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CORPS OF ENGINEERS, U. S. ARM'VJtt. ••
21
MISSISSIPPI RIVER COMMISSION
SOIL COMPACTION INVESTIGATION
REPORT NO.1
COMPACTION STUDIES ON CLAYEY SANDS
TECHNICAL. MEMORANDUM NO. 3-,271
WATERWAYS EXPERIMENT STATION
VICKSBURG, MISSISSIPPI
PRICE $1.00
APRIL. 1949
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1. REPORT DATE APR 1949 2. REPORT TYPE
3. DATES COVERED 00-00-1949 to 00-00-1949
4. TITLE AND SUBTITLE Soil Compaction Investigation: Report No. 1: Compaction Studies onClayey Sands
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5b. GRANT NUMBER
5c. PROGRAM ELEMENT NUMBER
6. AUTHOR(S) 5d. PROJECT NUMBER
5e. TASK NUMBER
5f. WORK UNIT NUMBER
7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Army Corps of Engineers,Waterway Experiment Station,3903 HallsFerry Road,Vicksburg,MS,39180
8. PERFORMING ORGANIZATIONREPORT NUMBER
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14. ABSTRACT
15. SUBJECT TERMS
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Report (SAR)
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Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18
CORPS OF ENGINEERS, U. S. ARMY
MISSISSIPPI RIVER COMMISSION
SOIL COMPACTION INVESTIGATION
REPORT NO.1
COMPACTION STUDIES ON CLAYEY SANDS
TECHNICAL MEMORANDUM NO. 3-271
WATERWAYS EXPERIMENT STATION
VICKSBURG, MISSISSIPPI
MRC·WE5-100-APRIL 1949
APRIL 1949
Report No. Title Date
1 Compaction Studies On Clayey Sands April1949
PREFACE
This report is the first of a series of reports to be published on
various studies comprising a comprehensive soil compaction investigation.
This investigation was authorized by the Office, Chief of Engineers, in
May 1945 and performed by the Waterways Experiment Station in accordance
with "Instructions and Outline for Soil Compaction Investigation" dated
June 1945.
CONTENTS
PREFACE
PART I: INTRODUCTION •
Purpose of the Study Scope . • • . . . . . Definition of Pertinent Terms
PART II: TEST FILLS ....
Preliminary Survey Work . . • . Location and Preparation of Materials Construction • . . . . . . • . • .
PART III: FIELD SAMPLING AND TESTING
Procedure and Methods ...•••.
PART IV: lABORATORY TESTING OF UNDISTURBED SAMPLES
PART V: RESULTS OF FIELD AND lABORATORY TESTS
Method of Presentation of Test Data •..... Construction-Lift Moisture-Density Data Field In-Place, CBR, Moisture, and Density Test Data CBR, Moisture, and Density Data from Undisturbed Samples
Taken in Cylinders . . . . . . . . . . . Results of Unconfined Compression Tests
PART VI: DISCUSSION OF CBR TESTS •
PART VII: SUMMARY AND CONCLUSIONS
TABLES 1-5
PHOTOGRAPHS 1-24
FIGURES 1-30
1
1 1 3
7
7 10 12
23
23
26
27
27 27 29
30 35
37
4i
SOIL COMPACTION INVESTIGATION
CLAYEY SAND TEST FILLS
PART I: INTRODUCTION
1. Presented herein are the results of a combined field and lab-
oratory study on the compaction and stress-strain characteristics of a
clayey sand. This study is a part of a comprehensive soil compaction
investigation approved by the Office, Chief of Engineers, in May 1945,
and performed by the Waterways Experiment Station in accordance with
"Instructions and Outline for Soil Compaction Inveatiga'tion" dated June
1945. This report is the first of a series of reports to be published
on the various phases of the comprehensive investigation.
Purpose of the Study
2. The specific purposes of this phase of the investigation are
stated in subparagraphs 2-b and 2-c of the "Instructions and Outline"
as follows:
"2-b. Determination of the stress-strain characteristics of soils compacted in the field by equipment now readily available for compaction purposes.
"2-c. Determine the feasibility of the utilization of field compaction equipment of types now generally in use to obtain much greater compaction than is now generally required in fills."
Scope
3. The results of the investigation described in this report
2
provide a partial realization of the above-stated purposes. Objective "2-b"
was not completely realized inasmuch as only CBR and unconfined compres-
sion tests were performed. Triaxial compression tests were scheduled but
could not be performed because the samples could not be protected from
high summer temperatures and cracked and dried out. Additional work is
required to completely realize objective "2-c" because certain factors
that affect compaction were held constant in this investigation and must
be made variable in future work so that a complete determination of the
effect of all factors influencing compaction will be accomplished. Brief-
ly, the study was to consist of the following phases of work:
a. Preliminary survey work to locate a source of clayey sand material, and tests to determine the physical characteristics of various clayey sand mixes under dynamic and static compaction in the laboratory.
b. Construction of test fills of clayey sand using the following types of equipment for compaction: 34,500-lb D-8 tractor; a sheepsfoot roller loaded to produce 250, 450, and 750 psi; 19,500-lb wobble-wheel roller (1500 lb per wheel); 10,000-, 20,000-, and 40,000-lb rubber-tired wheel loads.
c. Field sampling and testing of test fills.
d. Laboratory tests on undisturbed samples procured from the test fills.
The variables present in any compaction work on a given soil with a given
type of equipment are: (1) weight of roller, (2) contact pressure, (3)
number of coverages, and (4) thickness of lifts. Items (1), (2), and, to
-a limited extent, (3) were investigated for compaction by sheepsfoot
rollers. Item (l) was investigated for compaction by rubber-tired
rollers. The other variables mentioned above but not investigated were
outside the scope of the tests described in this report.
Definition of Pertinent Terms
4. For purposes of clarity, various terms used in this report are
defined as follows:
3
Unit. A unit or test unit consists of an area of natural sub
grade or a portion of a compacted fill which is compacted during the test
at a given water content and under a given compactive effort with a given
piece of compacting equipment.
Section. A section (usually several units) is an area of natu
ral subgrade or a portion of a compacted fill constructed using one com
pactive effort at several water contents. A section, therefore, consists
of a test area which is utilized in determining all or a part of a
compaction curve for a given number of passes of a given piece of com
pacting equipment.
Compactive effort. This term can apply to either field or
laboratory compaction. In the case of laboratory compaction a compactive
effort consists of the application of a given amount of energy per unit
volume of compacted soil. The compactive effort can be varied in the
laboratory by changing the weight of the compacting hammer, number of
blows per layer, or number of layers of soil in the compaction cylinder.
In the case of field compaction a compactive effort consists of compaction
by a given piece of equipment passing a given number of times on a given
thickness of lift.
Trip. A trip of the compacting equipment refers to the pass
age of the equipment from one end of the compacted section to the other
in one direction only. The term "round trip" is used for designation of
a trip from one end of the section to the other and back.
4
Coverage. One coverage consists of one application of either
a wheel of a rubber-tired roller or a foot of a sheepsfoot roller over
each point in the area being compacted.
Pass. For a rubber-tired roller, pass and coverage are syn
onymous. For a sheepsfoot roller, one pass consists of one movement of
a sheepsfoot roller drum over the area being compacted. The sheepsfoot
roller used in this investigation re~uired about 18 passes to accomplish
one coverage.
Sheepsfoot roller. A double-drum, oscillating sheepsfoot roller,
Model AD-132, manufactured by the American Steel Works. By loading the
drums with increasing amounts of Baroid, foot contact pressures of 250 and
450 psi were obtained with one row of feet in contact with the ground.
Each drum is 60 in. in diameter and has eight 7-in.-long feet in a row.
The area of each foot is 7 s~ in.
Wobble-wheel roller. This term applies to a wobble-wheel roll
er loaded to 1495 lb per wheel on 13 wheels, or 19,440 lb gross weight.
Tires were inflated to a pressure of approximately 40 psi. This roller is
referred to hereafter as a 1500-lb wobble-wheel roller.
20,000-lb wheel load. This load was furnished by a Model Super
C Tournapull of 12-cu-yd capacity loaded to a gross weight of 80,000 lb,
or 20,000 lb per tire. Tires were inflated to a pressure of approximately
55 psi; contact pressure was approximately 65 psi; and contact area was
approximately 308 s~ in.
40,000-lb wheel load. This load was furnished by a Tournapull
of 32-cu-yd capacity, loaded to a gross weight of 160,000 lb, or 4o,ooo
lb per tire. Tires were inflated to a pressure of approximately 57 psi;
contact pressure was approximately 69 psi; and contact area under this
load was 580 sq in.
5
California Bearing Ratio or CBR. A measure of shearing resist
ance of soils to penetration which is determined by comparing the bearing
value obtained from an arbitrary penetration-type shear test with a stand
ard bearing value obtained on crushed rock (average value of a large number
of tests). The standard results are taken as 100 per cent and values ob
tained from other tests are expressed as percentages of the standard. CBR
may be modified by the terms laboratory, field in-place, soaked or unsoaked,
according to conditions under which the testa were made; or by the terms
design or evaluation, according to the purpose for which the test results
will be used.
D,ynamic compaction. Compaction of soil by the impact of a free
falling weight or hammer.
Static compaction. Compaction of soil by gradually increasing
the compacting pressure, applied by means of a piston covering the entire
surface of the specimen, up to any given amount. In the Porter static
compaction method this pressure is 2000 psi.
Standard AASHO compaction. In this report it is assumed that a
soil material is compacted by standard AASHO effort so long as the effort
or-work expended per unit volume of compacted soil is the same as that
specified by standard AASHO method T-99-38. In order to perform CBR
tests on compacted material and to study the effect of mold size, the
standard AASHO equipment and methods were varied. However, in all cases
the effort expended per unit volume of compacted soil is the same.
Modified AASHO compaction. A modification by the Corps of
6
Engineers of the standard AASHO compaction method, consisting of dynamic
compaction in a CBR mold (6-in. diam) using 55 blows of a 10-lb hammer
ralling 18 in. on each of five equal layers. In this report the size of
mold was increased to study the effect of mold size, and the number of
blows was increased accordingly. The work expended per unit volume of
soil was the same in all size molds.
7
PART II: TEST FILlS
Preliminary Survey Work
5. Several possible sources of the clayey sand material in the
immediate vicinity of Vicksburg were explored and samples of the material
were tested in the laboratory for determination of compaction and CBR
characteristics. It was found that none of these materials satisfied
requirements of a low-swelling clayey sand of low to medium plasticity.
A pit was finally located near Clinton, Mississippi, about 40 miles east
of Vicksburg, which satisfied the specifications for the type material
desired for test fills. The borings indicated that, in-general, the pit
had approximately 1 to 6 ft of clayey silt overburden, underlain by ap
proximately 2 ft of clayey sand containing 65-80% sand, which, in turn,
was underlain by a layer of clayey sand more than 20 ft in thickness con
taining approximately 80-90% sand. Trial mixes of the two clayey sands
were investigated in the laboratory and it was found that a blend of
approximately 20% of the material containing 65-80% sand and 80% of the
material containing 80-90% sand would yield a satisfactory material for
test purposes.
6. Classification data for this material are shown on fig. 1 from
which it can be seen that the blended material has a uniform gradation
in the fine and medium sand sizes and a plasticity index of approximately
2. Soil similar to this type of material is found in much of the south
eastern United States and has been used to a considerable degree as a
base course material in highway and airport construction. The material
has also been used to a great extent as surfacing on secondary roads.
8
7· The results of dynamic and static laboratory compaction and CBR
tests on the clayey sand in the unsoaked and soaked condition are shown
on figs. 2-5. A series of unconfined compression tests on specimens com
pacted dynamically and tested in the unsoaked condition were also performed
on this material, the results of which are shown on fig. 6. It can be
noted by reference to fig. 2 that modified AASHO maximum dry density is
approximately 122 lb per cu ft at an optimum water content of 10%, and
that standard AASHO maximum dry density is approximately 116 lb per cu ft
at an optimum water content of 11.5%· The corresponding CBR values for
these two compactive efforts are 65 and 15, respectively, in the unsoaked
condition (fig. 2). and 47 and 15, respectively, for the soaked condition
(fig. 3).
8. According to Part XII, Chapter 2, of the Engineering Manual,
this material if used as a base course would generally be required to be
compacted to 95% of modified AASHO maximum density at modified AASHO op
timum water content. For this condition, which is 116 lb per cu ft dr,y
density at 10% water content, the unsoaked CBR is 27, whereas the soaked
CBR is 22. It is interesting to note that under 2000-psi static com
paction, which is the original Porter or California method of compaction,
this material has an optimum water content of approximately 13% and a
maximum dry density of 112 lb per cu ft. The unsoaked CBR for the 2000-
psi static compaction is 17, whereas the soaked CBR is 19. The reason for
the soaked CBR being higher than the unsoaked CBR is the manner in which
the statically compacted specimens are prepared for test purposes. Ini
tially the material is placed in the CBR mold and compacted by one applica
tion of the piston under 2000 psi. The top of the specimen is then
9
subjected to a CBR penetration teat. A maximum dr,y density of 112 lb per
cu ft, an optimum water content of 13%, and an unaoaked CBR of 17 resulted
from this penetration procedure. After penetrating the top of the apeci-
men, the top inch of the material is scarified and a base plate placed on
top of the mold. The mold is inverted and the 2000-pai load reapplied on
what was previously the bottom of the specimen as initially compacted.
This additional compaction increased the average density of the mold up
to about 114 lb per cu ft, while still at the same optimum water content
of 13%. The material is then allowed to soak, at the end of which time a
CBR penetration test is performed. This test resulted in a value of 19%-
For convenience and ready comparison of densities, water content, and CBR
values, these data are tabulated as follows:
Maximum Opt. Unconfined Type of Dry w .c. Compressive Strength
Compactive Density Per CBR in Per Cent Lb per Sq In. Effort LbLCu Ft Cent Unsoaked Soaked Unsoaked
Modified AASHO 122 10 65 47 20
95% Modified AASHO
116 10 27 22 12
Standard AASHO 116.4 11.5 15 15 10
Porter static 112 13 17 (2000 psi) 114.5* 13 19
111 13 3
*High density value due to recompaction as discussed in paragraph 8.
9. It can be noted by reference to the above tabulation that the
CBR at 95% modified AASHO density is less than one-half of that obtained
at modified AASHO density. Under standard AASHO density ~he CBR is only
about one-fourth of that obtained under modified AASHO density. Also,
10
under modified AASHO the unconfined compressive strength is 20 psi in
the unsoaked condition, 12 psi at 95% of modified AASHO density, and 10
psi under standard AASHO density. The unsoaked CBR value of 17 obtained
on specimens compacted under 2000-psi static compaction is in the general
range of that obtained under standard AASHO compactive effort, but the
unconfined compressive strength of 3 psi is much lower than that ob
tained for standard AASHO effort.
Location and Preparation of Materials
Location of test site
10. Because of the proximity of the clayey sand pit to the Clinton,
Mississippi, Sub-Office of the Waterways Experiment Station, it was de
cided to construct the test fills on a portion of this reservation.
Pit operations
11. A total of approximately 15,000 cu yd of clayey sand mate
rial was needed for the tests. After stripping, it was found that soil
variations occurred rather frequently but that in general the soil con
sisted of the two types discussed in paragraph 5. According~y, the mate
rial was examined at the borrow pit by an inspector, who classified the
material as one or the other of the two basic types of clayey sand. The
soil was excavated by a dragline using a 1/2-cu-yd drag bucket and trans
ported to the test site by from three to six trucks of 3-cu-yd capacity.
Stock piles
12. The two clayey sand materials were stock-piled in adjoining
areas at the field site. The material was spread on each stock pile in
11
thin layers, approximately 3 in. thick, with four-directional blading to
produce intimate mixing and to crush out lumps. The water content of the
interior of both stock piles remained close to 10%. It was necessary to
air-dry the materials to reduce the water content to approximately 7% so
that the material would flow freely through the batching bins of the
mixing plant. Spreading and windrowing accelorated the drying. This
air-dried clayey sand was piled in the areas adjacent to the mixing plant.
During the latter part of the construction period an aggregate drier was
used to accelerate drying of the clayey sand for use in the dry units of
sections 8 and 9.
Mixing plant
13. The mixing plant consisted of a two-compartment aggregate bin
with a three-beam batching scale mounted above a pugmill driven by a
Diesel engine. A spray bar was installed over the pugmill and connected
to a water batching tank with manual controls and gage. Clayey sand was
loaded into the bins by a dragline equipped with a 1/2-cu-yd clamshell . bucket. The clayey sand batch was weighed out and dumped into the pugmill.
Water was added during the first part of the mixing period while the next
batch was being weighed. The size of the batch was established at 1250 lb
dry weight, which was sufficiently below the pugmill capacity to allow
operation at a uniform speed. Batch weights were computed on a dr,y basis
so that the setting of the scales was changed only with changes in the
stock-pile water contents and not with changes in the batch water content.
The plant produced 50 to 55 batches an hour when the stock-pile materials
were dry enough to flow freely. As the water content of the materials
12
increased from 6% to 8 or 9%, sticking and bridging acted to slow down
the :production.
Construction
Layout
14. The test sections as actually constructed are shown on the lay-
out on fig. 7. It can be noted that similar sections were :placed in the
same test area. This :permitted simultaneous construction of one section
of each ty:pe without traffic congestion. The ram:p and shoulder limits
were :placed to allow shoulder slo:pes of approximately 1 on 5 and ram:p
slo:pe of 1 on 10. A 20-ft transition of clayey sand was placed between
the ram:ps and the end units of the test section to receive the carry-
over of :pit materials and to permit the entry of compaction equipment
into the first unit at proper s:peed. Allowance was made on the 20,000-
and 40,000-lb wheel load sections for the large turnarounds required by
the Tourna:pulls. The test section number together with the type and
number of :passes of compaction equipment used is summarized below.
Test Section Compactive Effort in Construction Number Width-Ft Length-Ft Equipment Used No. of Passes
2 50 200 450-:psi shee:psfoot 9
3 40 200 250-:psi sheepsfoot 9
5* 30 200 D-8 tractor 3
6** 30 200 1500-lb wobble-wheel 6
8 30 200 20,000-lb wheel load 4
9 40 200 40,000-lb wheel load 4 on 1/2 section 8 on 1/2 section
* Section 5 constructed 2 ft high; all others 5 ft. ** Section 6 constructed in 3-in. lifts; all others constructed in 6-in.
compacted lifts.
13
It was originallY intended to construct a section with a 750-psi sheeps
foot roller and a section with an 8,000-lb wheel load. These sections
were eliminated however in the latter part of the program for reasons
that are discussed in paragraph 47.
Ground-water conditions
15. At the start of field construction in June 1945, the ground-
water table at the test areas was from 3 to 4 ft below the surface. In
October the depth to ground water was greater than 6 to 7 ft. This
change may be accounted for by normal seasonal fluctuation.
Subgrade preparation
16. The site was first cleared of brush and a system of connecting
surface drainage ditches was built. The subgrades of the test areas were
stripped of root-bearing topsoil and were scarified with a 24-in. disk
and a Killifer plow. The water content of the subgrade soil was gener-
ally above its standard AASHO optimum, and the areas were left to dry
during the period of clayey sand borrowing. From time to time they were
opened up, aerated, and resealed. It was finallY necessary to remove
1100 cu yd of wet subgrade soil and to replace it with material at a
lower water content. Compaction of the refill material was performed
with a tractor and wobble-wheel roller and the compacted areas were bladed
to finished grade with a motor patrol. This procedure resulted in a firm
subgrade satisfactory for the compaction test fills. All of the test .
areas were finished with slopes adequate' for the quick drainage of rain-
fall, using the natural ground surface to maximum advantage. Prior to
placing the first lift of clayey sand the subgrade surface was wetted to
14
restore proper moisture conditions.
Operation of compaction equipment
17. Sheepsfoot rollers. One sheepsfoot roller, an American Steel
Works Model AD-132, was used in order to obtain the unit foot pressures
required in construction of the clayey snnd sections. The operating speed
for all compaction equipment was first established at 3 mph. It was
desired to have the test sections compacted so as to cover a range of
density from approximately 95% of standard AASHO maximum density to
greater than 100% modified AASHO density, if possible. The nUmber of
passes to bo made with the 250- and 450-psi weights of sheepsfoot roller
was therefore selected by preliminary experimental tests with the 250-psi
roller. It was desired to approximate 95% of standard compaction with
this roller. A unit consisting of three 6-in. lifts was constructed
using the clayey sand at approximately standard AASHO optimum water con-
tent and compacted in lanes using 6 to 18 passes; The densities produced
in this unit were as follows:
Number Dry Density Water Content of Passes Lb[Cu Ft Per Cent
6 108.2 11.4· 9 110.3 11.4
12 112.0 12.0 15 113.4 12.5 18 114.3 11.2
The standard AASHO optimum density of the clayey sand was approximately
ll6 lb per cu ft. The number of passes constituting the sheepsfoot roller
efforts was established on the basis of these 250-psi data as nine, which
gave approximately 95% of standard AASHO density or 110 lb per cu ft.
15
The nine passes were performed in two series of trips; in the first aeries
the roller was offset one tractor tread width (22 in.) each trip. Thus,
when the tractor progressed completely across the section, the area had
received two coverages of the tractor and six passes of the roller; the
second series, offset two tread widths (44 in.) each trip, produced the
remaining three passes of the roller.
18. It has been stated previously that the nominal or "rated"
pressure intensity of sheepsfoot rollers is customarily computed with one
row of feet in contact with the ground. This condition seldom if ever
exists during actual operation. When the feet penetrate the soil more
feet come in contact with the ground and the contact pressure may be
reduced. For example, if the feet of the roller used in these tests
penetrate the ground to such an extent that the drum of the roller just
touches the ground, then the extremities of 24 teeth are below the sur
face of the ground. A penetration of only 4 in. will place the ex
tremities of 16 feet below the ground surface.
19. The distribution of the forces involved on the different rows
of feet of the roller is not known but is probably quite complex. It
is probable that the feet emerging from the soil carry no load whatever
on the face of the foot, but may have a pressure on the shank of the foot
due to a "kicking" action discussed in a later paragraph. The load car
ried by the feet as they penetrate the soil undoubtedly varies over wide
limits. It is probable that, with the roller in normal operation, a por
tion of the force required to pull the roller acts principally on the
feet that are forward of the center of the drum and in contact with the
soil. This force, while dependent on the weight of the drum, is an
16
addition to theforcesdeveloped by the dead weight of the drum acting
alone.
20. The greatest possible load that could be carried by the feet
occurs, during normal rolling operations, when the soil is so compact
that only one row of feet is in contact with the soil. The least possible
axial load applied to a row of feet during normal rolling operations would
result if the following assumptions are made: (1) the feet emerging from
the soil carry no load; and (2) each foot below and forward of the center
of the drum in contact with the soil carries an equal axial load. For the
roller used, six rows of feet are in contact with the soil when the drum
just touches the ground. Three rows of feet are emerging and are assumed
to carry no load. Three rows of feet are thus carrying the load and the
axial pressure is therefore one-third of the rated foot pressure.
21. Another factor to be considered that affects the performance
of a sheepsfoot roller, as explained below, may be called the effective
or pitch diameter. The effective diameter is determined by observing the
number of revolutions of the roller required for the roller to traverse
a given distance. It is probable that the effective diameter is not con
stant for a given roller but varies with the type of soil, water content,
and depth of penetration of the feet.
22. The drum of the roller used in this study was 66 in. in length
and 60 in. in diameter. The length of feet was 7 in., making the over
all diameter 74 in. There were 120 feet on the drum (30_rows at four
feet per row), and the end area of a foot was 7 sq in. If the effective
radius is taken as 37 in., one-half the over-all diameter, then the area
of a cylinder with a 37-in. radius and a 66-in. length is about 15,300
17
sq in. The total foot area is 840 sq in. so that the foot area is about
5-5% of the total area and about 18 passes of the roller are required
for one coverage.
23. It can be shown graphically, by construction of a cycloid,
that the feet of a roller enter and emerge from the soil in an almost
vertical position if the effective radius is taken as the distance from
the center of the drum to the outer end of the foot. Further, the roller,
in effect, pivots about the end of the foot directly beneath the center
of the drum and there is no relative horizontal movement between the face
of the foot and the ground. However, if the radius of the drum is taken
as the effective diameter, then the feet make a greater angle with the
vertical when they penetrate and emerge from the soil. Also, the pivot
point is now not at the outer end of the foot but at the point where the
foot joins the drum. The face of the foot now moves horizontally with
respect to the ground; the movement is to the roar, resulting in a kicking
or shovel action. It is reasonable to suppose that a greater force would
be required to tow the roller in the latter case. The actual effective
diameter probably lies between the two extreme values just pointed out.
24. It was stated in the preceding paragraph that the effective
diameter determined the position of the foot with respect to the vertical
as it entered and emerged from the soil. If the position from the ver
tical is appreciable, the side of the shank will contact the soil when
entering or emerging. This fact further complicates the computation of
actual foot pressures. If the side of the foot or the shank contacts the
soil they will carry some part of the load and the pressure on the face
of the foot (paragraph 18) will be further reduced.
18
25. Inasmuch as the feet always penetrate into the ground a cer-
tain distance it is obvious from the discussion presented in the preceding
paragraphs that when a layer of soil is compacted the pressure intensity
on the face of the foot is not equal to the nominal or rated pressure,
nor has the 1ayer received a complete coverage with the number of passes
used in the test. The stress developed in the soil beneath a roller foot
diminishes with depth below the face of the foot but, at the same time, the
area stressed increases. Thus, at some depth the areas subjected to stress
from adjacent feet on the roller begin to overlap and a complete coverage
results. However, the pressure intensity on the plane of such a complete
coverage is much less than the pressure at the face of the foot.
26. Pneumatic-tired rollers. It was desired that the equipmen~ used
for each wheel load should be capable of exerting approximately the same
contact pressure on the fill being compacted and the range of densities
desired was to be the same as that specified for the sheepsfoot rollers
(paragraph 17). The number of coverages to be made with the pneumatic-
tired rollers was therefore selected by constructing and testing an
experimental unit similar to that constructed with the 250-psi sheepsfoot
roller. The range of densities obtained in the clayey sand with a tire
load of 8000 lb is shown below:
Number Dry Density Water Content of Coverages LbLCu Ft Per Cent
2 111.8 14.0 4 114.'0 12.5 6 115.8 12.6
.8 116.1 12.1
These data indicate that two coverages of this wheel load produced a
19
density slightly greater than 95% of standard AASHO optimUm. However, in
the interest of obtaining uniform compaction, the tire-load efforts were
established at four coverages. Tire-load compaction was performed by
moving the equipment over one tire~print width per trip, the outside wheel
track thus meeting the inside wheel track.
27. Wobble-wheel roller. Compaction with the 1500-lb wobble-wheel
roller load was performed using six coverages in accordance with the
directive.
28. Tractor. Compaction with the 34,500-lb D-8 tractor was per
formed using three coverages, which was the number of tractor coverages
made in pulling the sheepsfoot roller nine passes, as discQssed in the
latter part of paragraph 17.
Fill construction
29. General. The clayey sand sections were built in the following
order:. (l) section 6, 1500-lb wobble-wheel load; (2) section 3, 250-psi
sheepsfoot; (3) section 5, 34,500-lb tractor; (4) section 2, 450-psi
sheepsfoot; (5) section 9, 40,000-lb wheel load; and (6) section 8,
20,000-lb wheel load. Mixing and placing of the material were continuous
during two 10-hr shifts, with two sections being worked simultaneously.
Compaction was carried out during daylight hours. The five units of each
section, planned to bracket the optimum water content of the clayey sand,
were arranged with water content increasing from south to north, down
slope. In the sections adjoining shoulders (sections 3, 5, 6 and 8) each
unit was entered directly from the shoulder, so that a minimum amottnt of
compaction would be caused by filling and spreading operations. For the
same reason, the interior sections (sections 2 and 9) were reached by the
20
end ramps, and filling progressed from the center unit to the ends.
Ramps and shoulders were brought up level with fills and were built by a
scraper with subgrade soil from nearby shallow borrows. No surfacing was
used on ramps and turnarounds.
30. Protective surface covering. .Each section was protected from
excessive evaporation and from rainfall by covering throughout the con
struction period. While allowance for evaporation was made in the mixing
water, the length of exposure was variable and unpredictable. The covers
used were 18 by 42 ft and 18 by 52 ft and were made of prefabricated bitu
minous surfacing (PBS) which was available in rolls 300 ft long and 3 ft
wide.
31. Placement procedure. Operations were begun with water content
determinations on the material ready for placement in the plant hoppers
and computation of batch quantities. The subgrade of the unit to be
built was uncovered and mixing and hauling started. The water content of
the mix was checked by grab samples from the second load and from every
eighth to ninth load thereafter. On the fill, each load was dumped in a
pattern based on the quantity of clayey sand computed for the unit lift
and the 2500-lb truck load. The material was spread and leveled by bull
dozers as soon as placed. A light tractor bulldozer was used in sections
3 and 6; a D-7 tractor bulldozer was employed in the other sections. Bull
dozers were used in preference to a motor patrol for this work, because of
their better maneuverability and low contact pressure. As rapidly as the
material was spread, the PBS covers were replaced, to remain until the
entire section was ready for compaction.
32. Compaction. Immediately prior to compaction the entire section
21
was uncovered and plowed with one pass of a Killifer plow, one pass of a
Seaman pulvimixer, and a second pass of the Killifer, as shown in photo-
graph 1. The water content of the loose layer was checked in samples from
the center of each quarter of each unit. In a few instances water content
adjustment was made by leaving the unit in question exposed while re-
covering the rest, or by sprinkling with a tank truck and repeating the
mixing and testing. The first pass of the compaction equipment followed
the final pass of the Killifer. In a representative number of lifts,
check water content determinations were made after rolling was completed.
When compaction operations were completed the section was again covered
and remained so until placement of the next lift began. After compaction
of the last lift in each section, the surface was dressed with a blade
when necessary and then covered with PBS mat. The compaction of each
section is described below.
a. Section 6 (1500-lb wobble-wheel load pulled b rubbertired tractor • This section was constructed in 3-in. compacted lifts with average water contents in the units, respectively, of 8, 10, 12.5, 14, and 15.5%. Because trucks and roller bogged down in the wet end of the section, the water contents were changed beginning with the third lift to 6, 8, 10, 12, and 14%. Compaction of the 14% material was difficult. The rubber-tired tractor and wobble-wheel roller were seldom able to cross this unit without being towed. The material was displaced considerably when being rolled, which resulted in a very rough surface condition which had to be graded after each third lift was compacted. A light tractor bulldozer or light motor patrol performed this work.
b. Section 3 (250-psi sheepsfoot roller pulled b D-8 tractor • This section was constructed in -in. compacted lifts with average water contents in the units, respectively, of 6, 8, 10, 12, and 14%. In the 12 and 14% materials the roller produced a large degree of springing, and in the 14% material the pickup of material was excessive. The roller appeared to walk out about 3 in. during compaction of the 10 and 12% materials.
22
c. Section 5 (34,500-lb D-8 tractor). Material in this section was placed in 6-in. lifts at water contents in the various units of 6, 8, 10, 12 and 14%. The D-8 tractor produced some rutting and shoving in the 14% material. Elsewhere the compacted surface was regular. Vibration in the fill due to the moving tractor was much more noticeable than in the fills compacted by the sheepsfoot rollers pulled with the same tractor.
d. Section 2 (450-psi sheepsfoot roller pulled by 34,500-lb D-8 tractor). Material in this section was compacted in 6-in. lifts at water contents in the various units of 6, 7.5, 9, 10.5, and 12%. In the 12% material the roller produced a large degree of springing in the fill and a heavy material pickup. Very little walk-out of the roller during compaction was observed. The appearance of the roller in the different units after the first and last (9th) pass is shown in photographs 2-11.
e. Section 9 (40,000-lb wheel load). Material in this section was compacted in 6-in. lifts at water contents in the various un~ts of 6, 8, 10, 12 and 14%. Although the west half of this section was compacted under four coverages of the wheel load and the east half was compacted under eight coverages of the load, the behavior under load and appearance of the two halves were very similar. The progressive deflection of the fill under this wheel load as the water content increased is shown in photographs 12-16 for the first coverage and in photographs 17-21 for the last four coverages. In the 12 and 14% material, the deflections resemble flood waves with the fill in motion for several feet in every direction from the moving wheel. The heavy ruts shown in the 14% material (photographs 16 and 21) were developed progressively but with shifting and reshaping under each successive trip.
f. Section 8 (20,000-lb wheel load). This section was constructed in 6-in. lifts at water contents in the various units of 6, 8, 10, 12, and 14%. This wheel load produced deflections of somewhat less than 2 in. in the material at 12%, and between 2 and 3 in. in the 14% water content. In the latter, rutting took place and increased with the number of coverages and in rolling it was difficult to keep the compaction equipment in line.
23
PART III: FIEIJ) SAMPLING AND TESTING
33. During construction, water content determinations were made on
the material in each lift, and sufficient density tests made to obtain
preliminary information on the trend of density in several lifts. Follow
ing construction, density and water content determinations were made at
6-in. intervals throughout the entire depth of fill and test pits staked
in each unit. In each test pit, field in-place CBR tests were performed
at three depths and undisturbed samples in quadruplicate were obtained in
CBR molds and in cubic-foot boxes adjacent to the field in-place CBR tests.
Test pit samples were not taken below a depth of 34 in., as density deter
minations showed that densities did not increase below a depth of about
12 to 18 in.
Procedure and Methods
34. Samples for the construction-lift water content and density
tests were obtained in thin-walled steel cylinders 3-3/4 in. in diameter
and 5 to 6 in. in length. The cylinders were fitted with a threaded
driving.cap, an extension pipe 1-1/2 in. in diameter, and a pipe cap,
and were driven with 12- or 14-lb sledge hammers. Samples for the density
tests made after construction at 6-in. intervals throughout the depth of
the section were also obtained by this method.
35. The field in-place CBR tests were conducted in accordance with
instructions in Appendix C, "California Bearing Ratio Test as Applied to
the Design of Flexible Pavements for Airports," Waterways Experiment
Station Technical Memorandum 213-1, dated 1 July 1945. The improved
truck-mounted apparatus, with a surcharge weight of 30 lb on a
24
10-in.-diam plate, was used in all tests. CBR tests were made in opposite
corners of the test pit at depths of 3, 12, and 17 in. in section 5
(tractor compaction), and at depths of 3, 12, and 24 in. in the other
sections. The truck was backed over the pit on tracks of pierced plank
landing mat which protected the pit edges and the sample locations from
traffic disturbance. Samples for the density tests made in connection
with the CBR tests were obtained in thin-walled steel cylinders, 3 in.
in diameter and 3 to 3-1/2 in. in length. These cylinders were driven
by the use of a light-weight drop-hammer arrangement. Preliminary tests
showed that no appreciable differences in densities were obtained when
samples of the clayey sand material were taken by a hammer-driven cylin
der and a hydraulically-driven cylinder. As a result of some compaction
due to driving, samples taken with a hammer-driven cylinder of a material
in a relatively loose condition may have a slight~y higher density than
samples obtained with a hydraulically-driven cylinder or those taken in
test pits as described in the following paragraphs. Because of the greater
ease and rapidity in obtaining samples, the hammer driving was resorted to
in one phase of the test procedure.
36. Undisturbed samples for laboratory tests were obtained in
wooden boxes and cylindrical molds at the same depths that field in-place
CBR tests were performed. The box samples were 9-in. cubes and were
obtained by digging out around a soil pedestal, trimming the pedestal to
an approximate 9-in. cube and encasing it in paraffin and a wooden box.
The cylindrical samples were 6 in. in diameter and 6 in. long and were
obtained in a similar manner, except that the soil pedestal was trimmed·
oversize and a 7-in.-diam cylinder with a 6-in.-diam cutting edge was
25
forced down on the pedestal, so that a true cylinder-shaped sample was
obtained, The annular space between the sample and cylinder was filled
with paraffin and the top of the sample covered with wax paper and sealed
with paraffin. The pedestals were then cut free and the bases trimmed
and sealed with wax paper and paraffin. Typical steps in the sampling
operations are shown in photographs 22 and 23.
26
PART IV: lABORATORY TESTING OF UNDISTURBED SAMPLES
37. As previously mentioned, the undisturbed samples that were ob
tained in cylindrical molds from the various test units were taken in
duplicate at each elevation where CBR field in-place tests were performed.
Upon receipt in the laboratory, one of these samples was penetrated in
the as-compacted condition, and the second sample was placed in the soak
ing tank for a period of four days. At the end of the soaking period the
sample was subjected to a CBR penetration test. Density and water con
tent determinations ·were performed on each sample received in the
cylindrical molds.
38. The undisturbed samples seQured in boxes from the different
test units were used for obtaining specimens for unconfined compression
tests, which were performed on the material in the as-compacted condi
tion. An effort was made to perform unconfined compression tests on
soaked specimens in order to obtain shear strength data on this type of
material when saturated. At first, however, it was not possible to use
soaked specimens for these compression tests due to the fact that the
specimens fell apart when the paper towel with which they were protected
during soaking was removed. At a later date a different procedure was
used and unconfined compression tests on soaked specimens were success
fully accomplished. The small un~onfined compression testing device and
sampling apparatus developed by Dr. M. Juul Hvorslev were used for the
performance of these tests. The samples were prepared by letting an
entire box sample soak and then obtaining test specimens from the box
by means of the thin-wall Hvorslev sampler.
27
PART V: RESULTS OF FIELD AND lABORATORY TESTS
Method of Presentation of Test Data
39. All test points from field determinations were plotted and a
smoo~h curve drawn through the points. In all water content-density
plots the curve was quite well defined. Points on the dry side of the
optimum water content were sometimes as much as 3-4 lb per cu ft above
and below the average curve for any given water content, but the varia
tions were much less on the wet side of optimum. Variations of this
magnitude occurred in spite of the carefully controlled placement pro
cedures and are to be expected in field-compacted soils; however, good
average values were obtained by making a sufficient number of determina
tions. Deviations from the average curve were somewhat greater in the
case of CBR data, but the data shown are believed to represent the CBR of
the soil as accurately as may practicably be obtained by means of a test
of this nature.
Construction-Lift Moisture-Density Data
40. As previously indicated, density and water content determina
tions were made on construction lifts in the test sections as they were
constructed. The results of these tests on five of the test sections
are shown in figs. 8-12 and are typical of the data obtained. These
data are shown in the form of moisture-density curves for different lifts
in a given section. As indicated, the curves shown for a given piece of
equipment were obtained from tests o~ samples obtained at the same time
28
after the construction of a particular lift. For instance, on fig. 9
the typical moisture-density data shown for lifts 3, 4 and 5 were devel-
oped from teat data obtained on samples taken from each of these lifts
immediately after construction of lift 6. In general, the moisture
density curves for the lifts close to the surface of the fill are more
rounded in the vicinity of optimum water content than those at two to
three lifts below the surface of the fill. It can also be noted that
there is a tendency for the density at optimum water content to increase
slightly with increase in depth down to about 12 to 18 in. At the 18-in.
depth the tractor, 250-pai aheepsfoot roller, and 450-psi sheepsfoot
roller sections all have the same maximum density of about 114 to 115
·lb per cu ft at optimum water content. I
This is equivalent to approximately
94% of modified AASHO maximum density. For these same pieces of equip-
ment at the 18-in. depth the optimum water contents are approximately
13.5, 13 and 11.5% for the tractor and the 250- and 450-psi sheepsfoot
rollers, respectively.
41. In the case of pneumatic-tired equipment, reference to figs.
11 and 12 indicates that the observations regarding shape of compaction
curves and increase in density with increase in depth just pointed out
for the tractor and sheepsfoot rollers appear to hold equally as well
for rubber-tired equipment. In comparing densities for the wobble-wheel
roller at 3-, 6- and 9-in. depths with densities for the 40,000-lb wheel
load, it can be noted that the maximum dry density for the wobble-wheel
roller section (built in 3-in. lifts) and for the 40,000-lb section
(built in 6-in. lifts) is approximately 116 lb per cu ft (95% modified
AASHO density) at a constant optimum water content of approximately 12%.
29
Thus, it appears that pneumatic-tired equipment gives slightly greater
densities for the clayey sand material than the tractor or sheepsfoot
rollers, and it also appears that the equal densities obtained under
pneumatic-tired equipment were obtained at the same optimum water content,
whereas equal densities obtained under the tractor and sheepsfoot rollers
were obtained at varying optimum water contents.
42. It can be noted by reference to figs. 8-12 that, for all prac
tical purposes, the maximum densities obtained with the different types
of equipment did not show any marked changes beyond a depth of about l2
to 18 in. On this basis it was decided that it would not be necessary to
perform field in-place tests or to take undisturbed samples at depths
greater than 24 to 34 in. Actually, when field sampling and testing
were performed the maximum depth for field CBR tests was approximately
24 in., but density samples taken in connection with these CBR tests
and undisturbed samples taken in cylinders and wooden boxes came from
depths of 24 to 34 in. because of the length of the samples.
Field In-Place, CBR, Moisture, and Density Test Data
43. The results of field in-place CBR tests and corresponding
water content and density determinations made on samples taken in
volumetric cylinders immediately adjacent to the point where the in-place
CBR test was performed are shown on figs. 13-19. The curves shown on
these figures illustrate the variation of field in-place CBR and density
with water content for three different depths. Moisture-density data
substantiate construction-lift data previously discussed, with the possible
exception that the optimum water content for the 450-psi sheepsfoot
30
roller section is approximately 12.5% instead of 11.5% and is therefore
more nearly·equal to the 250-psi sheepsfoot roller and tractor optimums
than the differences indicated by construction-lift data. Although no
20,000-lb wheel load, construction-lift data were previously shown, the
field in-place data for this wheel load shown on fig. 17 are in agreement
with the wobble-wheel and 40,000-lb wheel load data.
44. The field in-place CBR data shown on figs. 13-19 are tabulated
below: CBR at 12-In. Depth CBR at 24-In. Depth Max- Min- At Opt. Max- Min- At Opt.
Equipment imum imum w.c. imum imum w.c.
Tractor 13 3 6 14 3 4* 250-psi sheepsfoot 19 2 8 15 1 12 450-psi sheepsfoot 20 4 9 19 9 14 1500-lb wobble-wheel 18 6 6 18 1 8 20,000-lb wheel load 18 2 8 19 2 9 40,000-lb wheel load 22 2 6 22 2 6
(4 coverages) 40,000-lb wheel load 28 8 8 23 2 5
(8 coverages)
* 17-in. depth
It may be seen from the above tabulation that for the tractor and sheeps-
foot compaction there is an apparent increase in both the maximum CBR and
the CBR at optimum water content with increase in weight of compacting
equipment. The data for the rubber-tired rollers do not reflect any poai-
tive effect of increased compactive effort for the CBR at optimum water
content but do show a tendency for the maximum CBR to increase with in-
crease in compactive effort.
CBR, Moisture, and Density Data from Undisturbed Samples Taken in Cylinders
45. The results of CBR tests made on unso&ked and soaked samples
31
taken in CBR molds from the various unite are shown on figs. 20-26 •.
The moisture-density curves shown on these figures were obtained from
water content and density determinations made on the sample received in
each cylinder. It can be noted that these curves are not in exact agree
ment with similar curves shown on figs. 13-19. This difference is prob
ably due in part to the slight variations in density and water contents
existing in the fill. Data for curves on figs. 13-19 are from volumetric
samples taken immediately adjacent to field CBR tests, while data on figs.
20-26 are from undisturbed samples taken at another location in the
test pit. With the exception of the tractor section, the data for each
type of compaction equipment were obtained on samples taken at three
depths; samples in the tractor section were taken at only two depths.
46. Tho maximum density obtained in the cylinders from the tractor
compacted sections was about 112 lb per cu ft, whereas the maximum den
sity of the cylinder samples from the 250- and 450-psi sheepsfoot roller
sections was about 115 to 116 lb per cu ft, although the optimum water
content as determined by data from the cylinder samples was constant at
12% for all three pieces of equipment. In the case of the pneumatic
tired equipment it appears that the wobble-wheel roller developed an
average maximum dry density of 116 lb per cu ft at an optimum water
content of about 12%, whereas the 20,000- and 40,000-lb wheel loads
had equal maximum densities of approximately 117 lb per cu ft at a
slightly lower optimum water content of approximately 11.5%.
47. As previously mentioned, it was intended originally to construct
test sections with a 750-psi sheepsfoot roller and an 8000-lb rubber-tired
wheel load. However, it was decided to abandon the 750-psi sheepsfoot
32
rol~er section, since examination of the field data revealed that the
250- and 450-psi sheepsfoot roller sections did not show any significant
differences in maximum density and optimum water content.
48. MUch the same reasoning was followed in eliminating the section
to be constructed using the 8000~lb rubber-tired wheel load. The first
section built with pneumatic-tired e~uip.ment was the wobble-wheel roller
section. As pointed out before, the wobble-wheel roller produced maximum
densities only slightly greater than those obtained with the sheepsfoot
rollers. Because of the trend of the sheepsfoot roller data and the fact
that the 20,000-lb wheel load rubber-tired e~uipment was being used else
where, it was decided to construct the 40,000-lb wheel load section im
mediately after the construction of the wobble-wheel roller section. The
40,000-lb wheel load e~uip.ment produced densities practically e~ual to or
only slightly greater than the wobble-wheel roller. In scheduling the
remainder of the construction it was therefore decided to abandon the
section to be constructed with the 8000-lb wheel load but to include the
20,000-lb wheel load in order to have a better spread of rubber-tired
wheel loads and to obtain a check on the wobble-wheel and the 40,000-lb
wheel load data.
49. The range of unsoaked CBR values at optimum water contents ob
tained from tests made on cylinder samples showed no significant differ
ences from values obtained by field in-place tests. This factor will be
more fully discussed in paragraphs 57 to 63.
50. One significant trend seems to stand out for all types of
e~uipment. This is for the case of the soaked CBR values, where it can
be noted by reference to figs. 20-26 that the material on the dry side
33
of optimum water content swelled sufficiently on soaking to cause pro
nounced lowering of the CBR value over that obtained for the unsoaked
condition at the same as-compacted density and water content. It is
also important to note that for any given difference in water content
from optimum, the soaked dry-side CBR and the soaked wet-side CBR were
approximately equal, and that the maximum soaked CBR occurs at optimum
water content. Also, the soaked and unsoaked CBR values at optimum water
content are approximately equal.
51. The variations in CBR and density with water content for ma
terial compacted in the laboratory and in the field are summarized on
fig. 27 for one depth at which samples were taken in the field. All the
data obtained from field in-place tests and from soaked and unsoaked CBR
tests on undisturbed samples from the 12-in. depth for all types of com
paction equipment used are shown on this figure. A review of previous
figures shows no significant difference in density and CBR values for
samples taken at various depths. Therefore, for purposes of comparison,
the 12-in. depth was taken as being representative of all depths.
52. The curves shown on fig. 27 are the same curves shown on
figs. 13-26 for the 12-in. depth. Also shown on this figure are the
results of standard and modified AASHO laboratory compaction tests and
corresponding CBR-water content curves for material in the unsoaked con
dition, together with the Porter 2000-psi static compaction data and CBR
curves in the unsoaked condition.
53. It appears from the data shown on fig. 27 that the compaction
characteristics of the tractor, sheepsfoot roller, wobble-wheel roller
and heavy rubber-tired rollers are very similar to those obtained by the
dynamic laboratory method of compaction. In general, the maximum dry
densities obtained in the field are equal to or slightly less than those
obtained by standard AASHO compaction and 6 to 10 lb less than obtained
by modified AASHO compaction. As previously shown by the construction
lift, field in-place, and cylinder data in fig. 27, approximately 94 to
97% of modified AASHO compaction was obtained by the field equipment for
the number of passes used. The range of CBR values of field-compacted
material was also more nearly equal to those obtained from specimens
compacted by standard AASHO effort than by modified AASHO or Porter
2000-psi compaction.
54. The optimum water content, maximum dry density, and CBR for
dynamic and static laboratory compaction, and all of the data from field
test fills compacted with various types of equipment, are tabulated and
shown in table 1. This table was prepared by first listing the optimum
water content and density developed by standard and modified AASHO labora
tory compactive effort and each piece of field compaction equipment. Two
values are shown for the field data because water content and density
values corresponding to field in-place CBR values were obtained from
density tests made adjacent to tho penetration test and similar data for
the undisturbed cylinder samples were determined directly from the sample
tested. The CBR values listed under the heading of "Field Compaction" are
actual field test values. The CBR values shown for laboratory dynamic and
static compaction in a 6-in. mold were obtained from figs. 2-5 for the
water content and density values listed in the figure. Data for the 7.4-
in.-and 12-in.-diam molds were taken from a letter report dated l
October 1945 to Office, Chief of Engineers,_ subject 11 Preliminary Results
35
of Tests to Study the Effect of Mold Size on CBR." This table permits
a direct comparison of CBR values of material compacted in the laboratory
and in ~he field at the same water contents and densities. It is impor
tant to note that at optimum water content the CBR values for soaked
undisturbed samples are about equal to the unsoaked value except for the
250-psi sheepsfoot roller section.
55. As it has been general practice to specify that a certain
degree of compaction be obtained at modified AASHO optimum water content,
the densities and CBR values obtained in the field at this water content
are given in table 2. For the clayey sand used in this investigation,
the modified AASHO optimum water content is 10%. In the case of the data
for the field-compacted specimens, the data shown in tables 1 and 2 are
taken from fig~. 13-26 for the 12-in. depth. These data show that none
of the field equipment approached modified AASHO density at this water
content for the number of passes of equipment used. It further shows
that all field CBR values are more nearly equal to CBR values obtained
on dynamically compacted laboratory specimens than on statically
compacted specimens.
Results of Unconfined Compression Tests
56., The results of unconfined compression tests performed on 2-
by 4-in. specimens cut from the undisturbed test pit samples obtained
from various units are shown on figs. 28 and 29. These data are for
the clayey sand in the unsoaked condition. Tests were performed on
samples taken from three different depths in the test fills but there
was no significant difference in the dry densities obtained at the various
depths. Therefore, all teat points were plotted (water content vs dry
density and compressive strength) disregarding depth. This resulted in
a sufficient amount of reliable data to allow plotting of water content
density curves and to establish a trend of variation of unconfined com
pressive strength with water content. Points shown on figs. 28 and 29 are
averages of several points, which were arrived at by using the same pro
cedure as was used in plotting the water content-density curves and the
variation of CBR with water content curves for the field-compacted fills.
Results of these tests are summarized on fig. 30. A comparison of un
confined compressive strength of laboratory-compacted specimens with
field-compacted specimens is shown in table 3. It appears from the data
shown in this table that the field-compacted material has strength
characteristics very similar to those of dynamically compacted laboratory
specimens. This is also true in regard to the strain characteristics of
the material, as no appreciable differences in the stress-strain curves
were obtained from material compacted by dynamic effort in the laboratory
or by sheepsfoot rollers or rubber-tired rollers in the field.
37
PART VI : DISCUSSION OF CBR TESTS
57. In the letter report to the Chief of Engineers, dated 1 October
1945, subject "Preliminary Results of Teste to Study the Effect of M:>ld
Size on CBR", it was shown that CBR values decreased with increasing mold
size. Additional data obtained from the field teste reported herein
permit further conclusions regarding the effect of mold size on CBR values
and are discussed in the following paragraphs.
58. It is considered that variations in CBR values due to mold
size may be due to at least two causes: (1) the confining effect of the
mold during compaction of the specimen; and (2) the confining effect of
the mold during the penetration of the specimen. CBR values of the clayey
sand were obtained from three sources: namely,
a. Specimens compacted in molds in the laboratory and penetrated in molds.
b. Undisturbed field samples, compacted in the field by field equipment and penetrated in molds.
c. Field in-place tests, compacted in the field and penetrated in the field.
Thus, if CBR values from ~ and ~ are equal to each other and are higher .
than ~ it would appear that differences are due to the confining effect
of the mold during the penetration of the piston. On the other hand, if
b and c are equal to each other and are lower than ~ it would appear that
differences are due to the confining effect of the mold during compaction.
59. Table 4 presents the ratio of CBR values for field in-place,
mold, and laboratory tests. Data shown under "Optimum Water Content"
were computed from values given in table 1, and under "10% Water Content"
from table 2. Column (1) ~is the ratio of CBR values from laboratory
38
compacted and penetrated molds to values from field in-place tests. It
is apparent that the laboratory values are higher than the field in-place
values for all types of compaction equipment and that the values of the
ratios fall naturally into two groups consisting of the tractor-sheepsfoot
rollers and the pneumatic rollers. Similarly, it can be seen in column
(2) that laboratory-compacted values are appreciably higher than field
mold values. It is not possible to get a ratio of field in-place values
to mold values directly, as the densities are not equal (tables 1 and 2).
However, an approximation can be obtained by simply dividing the ratios
in column (2) by those in column (1), as shown in column (3). The values
obtained are not absolutely correct, as the water contents are not con~
stant, but are sufficiently accurate for purposes of comparison. A
comparison of CBR curves on fig. 27 for field in-place and cylinder tests
shows that the computed ratios are approximately correct. Summarizing,
it appears that at the optimum water content for pneumatic rollers,
unsoaked CBR values from laboratory tests are about 2.1 times us great as
from field in-place tests and 2.9 times as great as from tests on un
·disturbed mold samples. Also, the field in-place values are about 1.4
times as great as mold values. The same trend is evident for the tractor
sheepsfoot datu but the differences are not as great.
60. The fact that CBR values from tests on undisturbed molds are
lower than values from field in-place tests cannot be definitely explained.
The method of obtaining the undisturbed mold samples has been explained
in paragraph 35 and illustrated by photographs 22 and 23. During sam
pling, all confining effects of the surrounding soil are removed and the
sample is thus afforded an opportunity to expand or to rebound from the
39
constraining effect of the surrounding soil and to reach a state of equi
librium with no confinement. Therefore, it' is probable that undisturbed
samples when tested in CBR molds actually have less confinement than soil
that is tested in place.
61. The data from soaked specimens in columns (4) and (8) show
much the same trend as pointed out for the unsoaked data at optimum
water content. The unsoaked data for 10% water content, which is dry of
optimum, are rather erratic. Note, however, that column (7) agrees with
column (3), in that field in-place CBR values are higher than values from
undisturbed molds.
62. Referring to paragraph 58, it is believed that the effect of
mold size on CBR values is due to a great extent to the confining effect
of the mold during compaction, as condition a is definitely greater than
conditions b and c. Positive conclusions <::annot be made concerning the
confining effect of the mold during penetration, due to the uncertainties
of the confinement of undisturbed samples penetrated in molds.
63. The foregoing discussion is not intended to establish any fixed
relationship between CBR values from field in-place tests and conventional
laboratory values, as sufficient data are not available for this purpose.
It is believed that sufficient data have been obtained to show, for this
particular soil, that field in-place values and laboratory values cannot
be used interchangeably, and that caution should be used with CBR values
from in-place tests for ever,y soil until some relationship has been def
initely established. The results of unconfined compression tests show
that the strengths of material compacted in the laboratory and in the
field (table 3) are about equal. This fact tends to confirm the opinion
40
that the low field in-place CBR values are not a true measure of the
strength of the soil relative to the strengths shown by laboratory com
paction tests.
64. Another char~cteristic of this clayey sand worthy of note is
that the soaked CBR value at low densities is practically independent of
water content, as can be seen by the curves in.the right hand plot of
fig. 3. Table 5 shows the CBR value at 1% dry of optimum, at optimum,
and 1% wet of optimum water content for all types of compacting equipment.
Thus, changes in water content near optimum are not critical for this
material, insofar as CBR values are concerned.
41
PART VII: SUMMARY AND CONCLUSIONS
65. Based on the data presented in this report, the following
summary and conclusions appear to be warranted for the clayey sand
studied:
a. Due to the highly plastic character of the material passing the 200-mesh screen (plasticity index= 45), the material exhibited compaction characteristics of a fine-grained material rather than a sand, as illustrated by the marked effect of moisture content.
b. The following maximum dry densities, expressed as a percentage of modified AASHO maximum density, were obtained:
No. of Height of Modified AASHO Eg_uipment Passes Lift - In. Densit;r in ~
34,000-lb tractor 3 6 91-92 250-psi sheepsfoot 9 6 94 450-psi sheepsfoot 9 6 93-95 15,000-lb wobble wheel 6 3 94-95 20,000-lb wheel load 4 6 95 40,000-lb wheel load 4 6 94-96 40,000-lb wheel load 8 6 95-97
It is noted that only a slight trend for increase in compaction occurred with the use of heavier equipment. It is further noted that the rubber-tired equipment gave slightly higher densities than did the tractor or sheepsfoot rollers for the number of passes used. The sheepsfoot roller did not walk out with i~creasing number of pusses.
c. The optimum water contents, as developed by field equipment, were about equal to optimum water contents ob-tained by standard AASHO compaction as shown in the following tabulation:
Compactive Effort
Standard AASHO Tractor 250-pei sheepsfoot 450-pei eheepsfoot 15,000-lb wobble wheel 20,000-lb wheel load 40,000-lb wheel load
Optimum Water Content
11.5 12.0 12.0 12.2 11.7 11.5 11.5
42
d. The stress-strain curves from CBR testa of field-compacted material were much more similar to curves of laboratory, dynamically compacted material than to statically compacted material.
e. In general, CBR values of field-compacted material did not agree with CBR values from laboratory-compacted material but varied in a systematic manner (see table 4).
f. The maximum soaked CBR for field-compacted material occurred at field optimum water content and the curve is symmetrical about this point for a range of about 2% in water content.
TABLES
Table ~
SUMMARY OF OPl'IMUM WADR Ccm!ENT 1 DENSITI 1 AND C:BR FCB I.ABCmATaRY AND J'IEU) CCIIPACTIOH
ciil:if'ornia Beari.iii !!!t1o tc:aal Static fA})()ft: Opt1llium Per Cent Dynamic IA'borator.;-CO!!IJ!!:CtiiiiiK
Water Max:iJiium of Fie~d Compaction .4-in. 12-in. to:z Compaction& Content Dry Modif'ied Undisturbed 6-in. Diameter Diameter 6-in.
Type of Per Density AASBO In ~lind. Samples Diameter Mold )t)ld )t)ld Diameter Mold CQ~~~PaCtion Egu1J!!!!nt Cent" LbLCU Ft Densitz Place oakedsoiked Unsoaked Soaked Unsoaked Uii&oaked Unsoaked w Modif'ied AASBO 10.0 122.2 100 65 47 52 19
Standard AASll> 11.5 ll6.2 95 15 15 14 4
Static 2000 psi 13.0 114.3 94 17 19
34,500-lb tractor 13.5b m.ob ~ 6 9 7 3 3 17 18 (3 coverages) 12.0C 1ll.5c 91 7 5 11 9 6 3 20 8
2,o-pa1 aheepsfoot 12.7 115.3 94 8 11 11 8 25 21 (9 passes) 12.2 114.5 94 12 8 12 11 10 4 28 l.8
450-pai aheepsfoot 12.4 m.5 93 9 9 10 7 4 25 17 (9 passes) 12.3 115.5 95 7 8 12 10 8 4 29 20
1500-1b wobble-whee~ 12.2 115.3 94 6 12 12 8 4 29 20 (6 coverages) 11.6 ll6.o 95 5 6 16 15 13 4 35 20
20,000-~b whee~ load 12.2 116.0 95 8 15 14 7 4 31 21 (4 coverages) 11.3 116.5 95 8 9 20 l.8 14 5 38 20
40,000-lb wheel load 12.2 ll6.2 95 6 15 14 6 4 31 21 ( 4 coverages) 11.5 117.0 96 1 8 24 20 14 5 38 21
40,000-lb wheel load 12.0 116.0 95 8 15 15 8 4 32 21 ( 8 coverages) 11.3 118.0 rn 13 13 32 23 15 5 4o 23
Botes: a IAborator;r OBR "t'al.ues correepond.ing to water contents and densities obtained in the field. b Water contents and densities correapcnUng to in-place OBR determined by volumetric samples taken adJacent to
teat location (parasraph 35) • c Water contents and densities correapcmd1ns to C:BR values of un41aturbed cylinder samples on which CBR teat was perf~ (parasraph 36). . Field data are frclll. 12-in. depth.
Table 2
SUMMARY OF DENSITY AND CBR FOR LABORATORY AND FIELD COMPACTION AT MODIFIED AASHO OPI'IMIJM WATER CONTENT
DyDamic Laborat~ COlllpa.ction Field Compaction CBRb Static Lab.
Dry Per Cent CBR 7.4-in. 12-in. Compaction CBBb Density of Mod. CBR Undisturbed 6-in. Diameter Diameter 6-in.
Type of at l~a AAsRO In Cllind. Samples Diameter Mold Mold Mold Diameter Mold Co~ction Eguipment w.c. Densitz Place Unsoaked Soaked Unsoaked Soaked Unsoaked Unsoaked Unsoak.ed Soaked
34,500-lb tractor 107 .• 5c 88 12 11 6 8 (3 coverages) 107.5d 88 9 6 11 6 8
250-psi sheepsfoot 109.5 90 19 12 9 11 3 17 8 (9 passe"') 110.5 90 14 8 12 10 12 4 22 9
450-psi sheepsfoot 108.5 89 16 11 8 10 4 12 7 (9 passes) 112.5 92 16 14 8 14 13 16 4 37 12
1500-lb wobble-wheel 110.0 90 15 -- 12 10 12 4 22 9 (6 coverages) 111.0 91 7 4 12 11 14 4 30 10
201 000-lb wheel load 110.0 90 13 12 10 12 4 22 9 (4 coverages) 113.2 93 10 6 15 14 18 4 39 13
401 000-1b wheel load 112.5 92 14 14 13 16 4 37 12 (4 coverages) 113-5 93 10 5 15 15 18 5 40 l3
4o,OOO-lb wheel load 111.0 91 16 12 11 14 4 30 10 ( 8 coverages) 115.2 94 15 10 22 19 . 22 6 45 16
Notes: a Modified AASHO optimum water content. b CBR values corresponding to densities obtained in the field at 1~ W .c. c Densities corresponding to in-place CBR determined by volumetric samples taken adjacent to test location
d (paragraph 35).
Densities corresponding to CBR values of undisturbed samples determined from cylindrical sample on which CBR test was performed (paragraph 36).
Field data are from 12-in. depth.
Type of Compaction Equipment
34,500-lb tractor (3 coverages)
250-pei sheepsfoot (9 passes)
450-psi sheepsfoot (9 passes)
Optimum
w. c. ~
11.5
1500-lb wobble-wheel 12.0 (6 coverages)
20,000-lb wheel load 11.7 (4 coverages)
40,000-lb wheel load 12.4 (4 coverages)
40,000-lb wheel load 11.0 (8 coverages)
Table 3
SUMMARY OF UNCONFINED COMPRESSION TEST DATA
Maximum Dry
Density Lb/Cu Ft
111.0
m.o
115.0
117 ·5
118.2
116.9
117 .o
Unconfined Compressive Strength Lb per Sq In.
Field Laboratory Uneoaked Soaked Unsoaked Soaked
6.1
6.0
6.0 6.0
9.3 10.6
7·5 11.5 7·5
9·5
ll.O 11.0
Dry Density 1~ w.c. 108.2
110.5
ll2.0
ll5.0
113.3
115.0
Unconf'. Comp:t-"ss. Strength Lb per Sq In.
at 1~ W.C • .:. Uneoaked Field Laboratory
8.8 8.2
10.1 7·5
10.0
ll.O 8.8
12.8 10.3
NOTE: All unconfined compressive strength data for the field were obtained from specimens cut from 9-in. cubic box samples. All laboratory unconfined compressive strength data were obtained from dynamically-compacted specimens. All laboratory values correspond to densities obtained in the field at the field optimum water content, and to 10~ water content (modified AASHO optimum) at the density obtained in the field.
Table 4
RATIO OF CBR VALUES FROM FIELD IN-PlACE, )I)IJ), AND lABORATORY TESTS
At Field QRtimum Water Content At 1~ Water Contenta
Unsoa.k:ed Soaked Unsoa.k:ed Soaked La.b.'D Lab. F.I.P. Lab. Lab. Lab. F.I.P. Lab.
Compaction F.I.P. MOld Mold Mold F.I.P. iiOid Mold MOld E!iui;2ment ~ll (2} Pl ~ ~5l ___@ ~7l ...@l
34,500-lb tractor 1.5 1.6 1.1 1.8 0.9 1.2 1.3 1.0 (3 coverages)
250-psi sheepsfoot 1.4 1.0 0.7 1.4 0.6 0.9 1.5 1.3 (9 passes)
450-psi sheeps:f'oot 1.0 1.7 1.7 1.3 0.7 1.0 1.4 1.6 (9 passes)
AVERAGE 1.3 1.4 1.1 1.5 0.7 1.0 1.4 1.3
1500-lb wobble wheel 2.0 3.2 1.6 2.5 0.8 1.7 2.1 3.0 (6 coverages)
20,000-lb wheel load 1.9 2.5 1.3 2.0 0.9 1.5 1.7 2.3 ( 4 coverages)
40,000-lb wheel load 2.5 3.4 1.4 2.5 1.0 1.5 1.5 3.0 ( 4 coverages)
40,000-lb wheel load 1.9 2.5 1.3 1.8 0.8 1.5 1.9 1.9 (8 coverages)
AVERAGE 2.1 2.9 1.4 2.2 0.9 1.6 1.8 2.5
Notes: a Modified AASBO optimum water content.
b Abbreviations in column headings have following meanings:
Lab. - Conventional laboratory CBR test in 6-in.-diam mold.
F.I.P. - Field in-place CBR test.
Mold - CBR tests QD. undisturbed samples taken in cylindrical :molds.
Table 5
CBR VALUES AT WATER CONTENTS DRY AND WET OF OPTIMUM
Compaction 3-in. Depth J2-in. Depth 24-in. Depth Equipment 1% Dry Optimum l% Wet l% Dry Optimum lop Wet lrfo Dry Optimum ltfr, Wet
250-psi sheepsfoot 7.0 8.0 8.0 8.5 8.0 7.0 8.0 10.0 10.0 (9 passes)
450-psi sheepsfoot 9.0 8.0 5.0 4.0 3.0 (9 passes)
1500-lb wobble-wheel 4.0 4.0 4.0 5.0 6.0 7.0 3.5 4.0 5.0 (6 coverages)
20,000-lb wheel load 5-5 6.0 5.0 6.5 9.0 6.5 8.0 10.0 8.0 (4 coverages)
40,000-lb wheel load 6.0 6.0 6.0 8.0 6.0 7.0 7.0 6.0 (4 coverages)
40,000-lb wheel load 10.0 lO.O 6.0 11.0 13.0 9.0 ]2.0 ll.O 7.0 (8 coverages)
34·, 500-lb tractor 2.0 3.0 (3 coverages)
4.0 6.5 5.5 3.0
Note: CBR values obtained from tests made on undisturbed samples.
PHOTOGRAPHS
Killifer plow and Seaman pulvimixer plowing material prior to compaction
-c ::c 0 -; 0 G> :::0 )>
-c :r: N
450-pei eheepefoot roller, first pa.ee, 6'1> water content
450-pei eheepefoot roller, first paee, 7-1/2~ water content
450-pei eheepsfoot roller, first pass, 9~ water content
450-pel sheepsfoot roller, first pass, 10-l/2~ water content
450-psi sheepsfoot roller, first pass, 12i water content
450-pei eheepefoot roller, ninth paee, 6% water content
450-pai sheepsfoot roller, ninth pass, 7-1/2~ water content
450-psi sheepsfoot roller, ninth pass, 9% water content
450-psi sheepsfoot roller, ninth pass, 10-1/2~ water content
"'0 :::r: 0 -f 0 G)
::0 )>
"'0 :::r:
450-pei eheepefoot roller, ninth pass, 12~ water content
40,000-lb wheel load, first coverage, 6% water content
40, 000- lb wheel l oad, first coverage , 8% water content
40, 000-lb wheel load, first coverage, 10~ water content
40, 000-lb wheel load, first coverage, 12% water content
40,000- lb wheel load, first coverage, 14~ water content
40,000-lb wheel load, fourth coverage, 6~ water content
00
40,000-lb wheel load, fourth coverage, 8% water content
40, 000-lb wheel load, fourth coverage, 10% water content
40,000-lb wheel load, fourth coverage, ~ water content
40,000-lb wheel load, fourth coverage, 14~ water content
Steps in obtaining undisturbed box samples in test pit
Steps in obtainine undisturbed cylinder samples in teet pit
PHOTOGRAPH 23
,
Steps in obtaining undisturbed cylinder samples in test pit
PHOTOGRAPH 24
FIGURES
., G1 c ::0 fT1
100
90
80
70
-.c 160 ~ a; c 50
LA: -c 4> :.l40 ...
Q..
30
20
10
Tyler Sieve Openinp in Inches Tyler Standard Sieve Numbers 3 2 15 105 074 053 037 3 4 6 8 10 14 20 28 35 48 65 100 150 200 I I I' I I I
r-.~ I I I I
['\
'\ L.L. PL. 'f.. I. S.G. ' 18 16 2. 8
\ M• T£1 IAL P I_CI~ /~( \
200 MESH t.t v.=-L.L. P.L. 'f.. I. 74 29 ~5
~
' 50 10 5 0.5 0.1 0.05 0.01 0.005 0.001
Grain Size in Millimeters
Large Gravel Medium Gravel · Silt Clay
CLASSifiCATION DATA FOR CLAYEY SAND
.., Ci c :XJ 1"'1
N
.... 1~0
12~
1-z ~ 100 a: Ill IL
!
"' 7!1
Ill u 0 Ill ~
~ a: a: 0 2!1 u
0
12!1
t: 120 ::> u a: Ill
liS IL
~ Ill ..J
! 110 ,.. !:: ~ z
10!1 Ill Q ,.. "' Q
100
10 IS 20
DYNAMIC COMPACTION IN 6-INCH-DIAMETER MOLD
325~~~~~~~~crii!JJ;~~~~~~~~ FIGURE BESIDE CURVE IS MOLDING WATER CONTENT
300
27S
22S
1-~200 u
"' Ill IL
! 17!1
~ u Q 1!:>0 Ill
t Ill
"' "'12!:> 0 u
100
75
50
25
130
ushPII~~~~~~~~~~DC~~ FIGURE BESIDE CURVE IS MOLDED DRY DENSITY
275
250
1-
~200 u «· Ill IL
! 175
"' Ill u Q 150 Ill
t Ill
~125 8
100
75
50
l!Q!L POINTS SHOWN OBTAINED BY IPITERI'OLATION
FROM DENSITY VS CBR Pl.OT.
O 5 6 7 8 9 10 II 12 WATER CONTENT IN PERCENT DRY WEIGHT
MOLDING WATER CONTENT VS DENSITY AND CBR
100 lOS 110 115 120 125 MOLDED DRY DENSITY IN LBS PER CU FT
DENSITY VS CBR MOLDING WATER CONTENT IN PERCENT DRY WEIGHT
WATER CONTENT VS CBR
o--o------
LEGEND SLOWS PER WEIGHT
~ ...L..A:a.B. ..I:IAYJiW!. !I 5 5 5 3
100 !Ill 26 12 12
IOL8S IOLI!S IOL8S IOL8S S.!:>LBS
DROP IN INCHES
18 Ill (MOD. AASHO) 18 18* 12
NOTES: SPI!:C.IIAEPIS TESTED AS MOLDED (U NSOAKED).
PI!:NETRATIDN SURCHARGE IOLBS.
* E:QUIV. TO STD. AASHO E:F"FORT
CBR, DENSITY AND WATER CONTENT DATA DYNAMIC COMPACTION, AS MOLDED
.. .. . ~ ~ -· -
DYNAMIC COMPACTION IN 6-INCH-DIAMETER MOLD •~o 130 130
FIGURE BESIDE CURVE IS MOLDINCO WATER CONTENT FIGURE BESIDE CURVE IS MOLDED DRY DENSITY
125 120 120
1-z ::l 100 110 110 "' Ill .... !
"' 75 100 100
ID ~ u POINTS. SHOWN OBTAINED BY INTER POLATIOI'( 0 F"ROM DENSI TV VS CBR PLOT. Ill 50 eo 110 t; Ill
"' "' 1- 1-0 25 ~eo z eo u Ill
u u
"' "' Ill Ill .... .... 0 ! 70 ! 70
"' "' ID ID u u
124 0 60 0 60 Ill ... t; t;
1- ... "' IL 120 "' 50 ~50 "' :;) 0 s u u
"' ... 40 .... 116 40
on ID ...1 . ! 110 30 30 > !:: on z
105 20 ... 20 0
> "' 0
100 10 10
1155 10 I !I 20 011!1 100 10~ 110 11!1 120 12!1 130 06 7 a g 10 II 12 13 WATER CONTENT IN PERCENT DRY WEIGHT MOLDED DRY DENSITY IN LBS PER CU FT MOLDING -TER CONTENT IN PERCENT DRY WEIGHT
MOLDING WATER CONTENT VS DENSITY AND CBR DENSITY VS CBR WATER CONTENT VS C8R !..~~~NO
IILOWS PER W!:IGHT DROP IN NOTES: SPECIMENS SOAKED I'ROM TOP !,.AYERS ~ ~ INCHES o--- !I 100 .10 LIIS 18 AND BOTTOM .
o--- !I !1!1 10 LIIS IIICMOO. MSHQ) SOAKING AND PENETRATION CBR. DENSITY AND WATER CONTENT DATA, - 5 26 lOLilS Ill SURCHARGE IDLBS. .,...___..._ !I 12 10 Lilli 1a• DYNAMIC COMPACTION. SOAKED - 3 12 5.!1LIIS 12 i1< EQUIV. TO STD. AASHO EI'I'ORT
...., G) c ;o ,...,
~ 1-z .. u a: .. .. ~ a: II u 0 .. 1:) .. a: a: 0 u
1-.. ~ u a: .. .. ., II ...J
~ > !::: ., z .. 0
> a: 0
STATIC COMPACTION IN 6-INCH-DIAMETER MOLD 150
FIGURE BESIDE CURVE IS MOLDIN,; WATER CONTENT FIGURE BESIDE CURVE IS MOLDED DRY DENSITY
125
100
75
50
25
0
130
120
110
300
275
250
1-
~200 u a: .. .. ~ 17!1
a: II u o ISO .. 1:) .. ~ 12!1 0 u
100
7$
50
2
100 0 0 5 10 15 100
WATER CONTENT IN PERCENT DRY WEIGHT
MOLDING WATER CONTENT VS DENSITY AND CBR
LEGEND
110 120 130 MOLDED DRY DENSITY IN LBS PER CU FT
DENSITY VS CBR
o--- 4000 PSI
D--- 2000 PSI
- IOOOPSI
NOTES: SPECIMENS TESTED M> MOLDED (UNSOAKED)
PENETRATION SURCHARGE 10 LBS.
STATIC. LOAD APPLIED F"RO!ol ONE END ONLY.
o ISO .. t .. a: a: 125
8
100
75
50
25
0
1!Q!L POINTS SHOWN OIJI"AINED BY INTERPOLATION
FROM DENSITY VS CBR PLOT .
6 7 II 8 10 II 12 13 MOLDING WATER CONTENT IN PERCENT DRY WEIGHT
WATER CONTENT VS CBR
CBR, DENSITY AND WATER CONTENT DATA STATIC COMPACTION , AS MOLDED
... z ... .... a:: ... G.
~ a:: Gl .... 0 ... ... .... ... a:: a:: 0 ....
! >... iii z
&0
50
40
30
20
10
0
130
STATIC COMPACTION IN 6-INCH-DIAMETER MOLD
&0
5!1
!10
45
... ~ 40 .... a:: ~ ~ 35
a:: Gl .... o30 ... t ... a:: 0::25 0 ....
20
I !I
FIGURE BESIDE CURVE IS MOLDING WATER CONTENT
!10
... z40
~ r ~35
II: Ill .... o30
t ... a:: 11:25
8
20
Ill
FIGURE BESIDE CURVE IS MOLDED DRY DENSITY
~ POINTS SHOWN OBTAINED BY INTERPOLATION
F'ROM DENSITY VS CBR PLOT .
Ill
115
... 110 10 10 0
>-a:: 0
!I
~ 0 0 5 10 15 100
WATER CONTENT IN PERCENT DRY WEIGHT
MOLDING WATER CONTENT VS DENSITY AND CBR
LEGEND
110 120 130 MOLDED DRY DENSITY IN LBS PER CU FT
DENSITY VS CBR
o--- 4000 PSI
IJo-- 2000 PSI
- 1000 Pill
NOTES: SPECIMENS SOAKED FROM TOP AND BOTTOM.
SOAKING AND PENETRATION SURCHARGE 10 LBS
STATIC LOAD APPLIED I'ROM f:ACH END 01' SAMPLE.
II
0 II 7 II 8 10 II 12 13 MOLDING WATER CONTENT IN PERCENT DRY WEIGHT
WATER CONTENT VS CBR
CBR. DENSITY AND WATER CONTENT DATA , STATIC COMPACTION. SOAKED
...., C) c ::0 , 0)
eo ... > iii "' 50 ... a:: II. ::E....: Ofli 40 Ua;
oz w-z k:'l: 30 Zto-01-' uz zw :Ill:
20 .... ., :::!
~ >< 10
~
0
12!1
.... ... :I u a:: ... II. 120
"' • ..J
! )-
!::
"' z 115 Ill
0
)-a:: 0
5 10 15 20 WATER CONTENT IN PERCENT DAY WEIGHT
DYNAMIC COMPACTION
FIGURE BESIDE CURVE IS MOLDING WATER CONTENT
eo
110
10
0 110 115 120 125
iii 50 a: z
... > :1 35
I 8 30
~ ~ 25 0 u z :I
10
0
FIGURE BESIDE CURVE IS MOLDEO DAY DENSITY
l!!ru;. POINTS SHOWN OBTAINED BY INTERPOLATION
FROM DENSITY VS COMPRESSIVE STRENGTH PLDT.
I 7 8 II 10 II 12 13 MOLDING -TEA CONTENT IN PERCENT DRY WEIGHT
MOLDING W.C. VS DENSITY AND COMP STRENGTH MOLDED DRY DENSITY IN LBS PEA CU FT
DENSITY VS COMPRESSIVE STRENGTH WATER CONTENT VS COMPRESSIVE STRENGTH
LEGEND BlOWS
PER ~ ~
o-- $ 58 o-- $ 27 A-- 5 13
WEIGHT DROPIN ~ INCHt.S
5.5 12 5.5 12 !1.5 12
NOTE$: SP~C.IIoU:NS C.OMPAC.TED IN 3..Cl-INCH-DIAMETER MOLD.
TESTED A5 MOLDED (UNSOAKED). VARIATION OF UNCONFINED COMPRESSIVE STRENGTH WITH DENSITY AND WATER CONTENT
,~,~, «>'
I 40'
I 4q I 40' llO'i 120'1 ~· 40'
I 40'
I 40'
I 40'l01
/ I
~~ /' ~ I I I
~ ...L.J1/i.&. ~ ~ ~ ~ ~ ~ ~
SECTION 6
0: SECTION 2 WOBBLE-WHEEL ROLLER
~ ~ ~ § ~ ~ 450-PSI SHEEPSFOOT ROLLER .J ~ ::> SECTION 3 0
~ :I: 250-F'St SHEEPSrOOT ROLLER
SECTION 9
"' I!!) fill ~ li!l gii] ~ I ON/0 0: 1£1 1!§1 (!!! ~ [i] ...!..!!!L!!J.. 40.()00·LB WHEEL LOAD. SAME
"' NO. CF COIIERAGES AS SEC. BON 0 l1iZI ~ !i4l ~ 5§1 ONE SIDE AND OOUBLE THIS
~ .J
I ::> NO. ON THE OTHER SlOE. I
~ 0 SECTION 8 :I: ~ ~ ~ ·IS!! ~
®= "' 20,00D·LB WHEEL LOAD.
I "'j I [§
PLAN <6-PLAN
50' 40' ~I I 1 ..
NOTE:
NUMBERS IN SQUARES INDICATE TEST
QT SEC.2 \ SEC.J ~ PIT AND UNIT NUMBERS.
-J ~5' -H-s• I JO',I, J()',,. 40' I Jq,l SECTION A-A L~ SEco\sEcs~
AREA I -l~s·~~ SECTION C-C
,~1~1,4~,1 ~·l4o·. I ~·
1~1 ABEA 4
SHOULDER / I OM J ' [t~ [!] ~ ~ ~ 1m
r !..!!! SECTION 5
j_~~ I I 34,500-LB TRACTOR
....... I ON J t / ION5~10N5
SHOULDER ®- I -1 2'
"' PLAN SECTION B-B
AREA 3 LAYOUT OF TEST AREAS
120
115
110
1- 105 LL..
~ u a: 100 w m tl.
(f)
ID _J
110 z
>-1-(f) 105 z w 0
>- 100 a: __ 0 115
110
105
100
FIGURE 8
SAMPLES TAKEN AFTER CONSTRUCTION OF LIFT 4
I"
5
j) ....
/ .... , .....:n ' /
/
' v
v /
~ r-.l_
v, 1'.. / 1\.
I'¥ ~
c ~
v .... v
"' ;.. :l ./ ' / -...
/ /
/ t1
hoo 10 15 20 WATER CONTENT IN PERCENT DRY WEIGHT
0
0
TYPICAL MOISTURE-DENSITY DATA FROM CONSTRUCTION LIFTS
SECTION 5 - 34,500-LB TRACTOR- 3 COVERAGES
LifT 3 DEPTH 6''
LIFT 2 DEPTH 12~'
LIFT I DEPTH 18''
120
115
110
1-...... 105 ::> u
a: 100 w
ll. 115
U) 10 ...J
z 110 ->-1--U) 105 z w 0
>- 100 a: 0 115
110
105
100
SAMPLES TAKEN AFTER CONSTRUCTION OF' Ll F'T 6
1-......
"""' p.
t;1
J ,. ~
'f"' 1..;'
I-' ~
b ~ ~"'-m
r ....
Lf 1/
1.1 ~I;'
v
""' 1--"t--
h
~
tr v
7 v
/'J
5 10 15 20 WATER CONTENT IN PERCENT DRY WEIGHT
TYPICAL MOISTURE-DENSITY DATA FROM CONSTRUCTION LIFTS
SECTION 3- 250-PSI SHEEPSFOOT ROLLER -9 PASSES
LIFT 5 DEPTH 6 11
LIFT 4 DEPTH 12''
LIFT 3 DEPTH 18''
FIGURE 9
120
I 15
110
1-~ 105 ::> u a:
100 w a. I 15 (/) co ...1
z 110
>-1-(/) 105 z w 0
>- 100 a: 0 115
110
105
100
FIGURE 10
SAMPLES TAKEN AFTER CONSTRUCTION OF LIFT 6
, ' l
;:J
/ " j..
(
/ (t/
:) .... I .
~
)'-lj
/
/
/ 1: '
'S 0 I/
II
I
/t)
I
1/
If
50 10 15 20 0 WATER CONTENT IN PERCENT DRY WEIGHT
TYPICAL MOISTURE-DENSITY DATA FROM CONSTRUCTION LIFTS
SECTION 2 -450-PSI SHEEPSFOaT ROLLER-9 PASSES
LIFT 5 DEPTH 6 11
LIFT 4 DEPTH 12''
LIFT 3 DEPTH 1811
rr5
110
ro5
~ ~
roo 3 120
a: w Q.
115 Cl)
10 .J
z 110 ->-~
Cl) 105 z 120 w 0
>-a: 115 0
110
105
roo
SAMPLES TAKEN AF'TER CONSTRUCTION OF L1 FT 7
p ~ , , ' /
~ ~
~
:) , /
}
1/ ..... ~ 1/ .Cl
1/ /
t)l' ~
~
ru
':\ol
L /
~ \,
~ I"
/ J)
, ¥
5 10 15 20 WATER CONTENT IN PERCENT DRY WEIGHT
TYPICAL MOISTURE-DENSITY DATA FROM CONSTRUCTION LIFTS
LrrT 6 DEPTH 3''
L I F'T 5 DEPTH 6''
LIF'T 4 DEPTH 9 11
SECTION 6- !,500-LB WOBBLE -WHEEL LOAD- 6 COVERAGES
FIGURE II
120
115
110
t 105
::::> 120 u a: w 115 ll..
(/) m _J
z 110
>-1- 105 (/)-z 120 w 0
>-a: 115 0
110
105
100
SAMPLES TAKEN AFTER CONSTRUCTION OF LIFT 5
v ...... - CDI 't:fd~
"" / ~~ I ·,
',(
~
\.
~---- 8 c ov. E"H4 G.~. ... ~ "(~
v if'!'-. ~---'r-4 cc Ill E". ~- IGES 1/ ..&.
/ l<.l' '-v I'
1/ 1.. , /
11'1 ~ 1-~--" 8 iOII ~f?, IG ~p
v~ 1/ \
I 4 c: rc v. ~.-~ IG~ 1"'1 ~
v \ / ~ "' \
~ 1/ r'l \
/
/ II
lS I
......
5 10 15 20
WATER CONTENT IN PERCENT DRY WEIGHT
TYPICAL MOISTURE-DENSITY DATA FROM CONSTRUCT ION LIFTS
LIFT 4 DEPTH 6''
LIFT 3 DEPTH 12"
LIFT 2 DEPTH 18"
SECTION 9-40 7000-LB WHEEL LOAD -4 AND 8 COVERAGES
FIGURE 12
...... (;) c ::0 1"'1
w
1-z "' u a: "' a. ~
a: 01 u
0
"' 1-u "' a: a: 0 u
50
40
30
20
10
0
DEPTH 3"
>z "' u a:
"' a.
~ a:
50
40
30
20
10
125
mtmmt~mm
~ 115 ., ., .J
~ 110
,.. >-
~ 105
"' 0
,.. :5 100
95 5 10 15
::: 120
:> u a: ~ 115
"' ., .J
~ 110 ,.. t II)
z 105
"' 0
,.. a: 0 100
20
DEPTH 12"
1- 50 z "' <.) a: ~ 40
~ a: "' 30 u
0
"' >-u 20
"' a: a: 0 u
10
0
~ 115
"' "' .J
~ 110
,.. ':: ~ 105
"' 0
,.. a: 0 100
DEPTH 17"
5 10 15 20 WATER CONTENT IN PERCENT DRY WEICHT WATER CONTENT IN PERCENT DRY WEICHT WATER CONTENT IN PERCENT DRY WEICHT
NOTES; WATER CONTENT VALUES USED IN CBR VS WATER CONTENT PLOTS WERE OBTAINED FROM DISTURBED SAMPLES TAKEN IMMEDIATELY BENEATH CBR PENETRATION PISTON.
WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT VS DENSITY PLOTS WERE OBTAINED FROM UNDISTURBED VOLUMETRIC SAMPLES TAKEN IMMEDIATELY AD~ACENT TO CBR TEST
VARIATION OF FIELD IN-PLACE CBR AND DENSITY WITH WATER CONTENT
SECTION 5-34,500-LB TRACTOR-3 COVERAGES
DEPTH 3" DEPTH 12 II DEPTH 24" 60 60 60
~0 ~0 50 ....
!Z !Z z "' u "' "' a: u u
40 a: 40 a: 40 II! "' w
a. a. ~ !: ~ a:
30 a: 30 a: 30 10 u 10 10 u u 0 0
"' 0 .... "' "' u 20 .... 20 tJ 20
"' u "' a: a: "' a: a: a:
0 0 a: u u 0
10 10 u 10
0 0 0 '
12!> 125 125
120 120 120
.... ... .... ... t-::> 115 115 ... 115 u ::> ::> a: u u
"' a: a: a. "' w 110 a. 110 a. 110 .,
10 "' :3 .J 10 .J .J
!: 105 !: 105 ~ 105 >- >- >-.... t- t: iii iii "' z z z "' 100 w 100 w 100 0 0 0
9!> 95 5 10 15 20 ~ 10 15 20
95 5 10 15 20
WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT
NOTES: WATER CONTENT VALUES USED IN CBR VS WATER CONTENT PLQlS WERE OBTAINED fROM DISTURIIED SAMPLES TAKEN IMMEDIATELY 8ENEATH CBR PENETRATION PISTON.
VARIATION fiELD IN-PLACE CBR AND WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT VS OF DENSITY PLOTS WERE OBTAINED FROM UNDISTURBED VOLUMETRIC DENSITY WITH WATER CONTENT SAMPLES TAKEN IMMEDIATELY AD..JACENT TO C8R TEST.
SECTION 3- 250-PSI SHEEPSFOOT ROLLER- 9 PASSES
...., C) c .::0 ,., (]I
60
50 ,... z w u cr 40 w 0..
~ a: 30 ID u 0 w ,... u 20 w a: a: 0 u 10
0
125
,... 120 ...
:::> u cr w 0..
115
U)
Ill -'
~ 110
>-1-iii z 105 w 0
>-a: 0 100
95
NOTES:
DEPTH 3" 60
50
,... z w u 40 a: w 0..
~ a: 30 ID u 0 w ,... 20 u w a: a: 0 u 10
0
125
,... 120 ... ::> u a: 115 w 0..
en Ill -' 110 ~ >-1-iii 105 z w 0
>-a: 0 100
95 5 10 15 20 5
WATER CONTENT IN PERCENT DRY WEIGHT WATER
WATER CONTENT VALUES USED IN CBR VS WATER CONTENT PLOTS WERE OBTAINED FROM DISTURBED SAMPLES TAKEN IMMEDIATELY BENEATH CIIR PENETRATION PISTON.
WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT VS DENSITY PLOTS WERE OIITAINED FROM UNDISTURBED VOLUMETRIC SAMPLES TAKEN IMMEDIATELY ADJACENT TO CIIR TEST.
DEPTH 12" DEPTH 24 11
60
50 ,... z w u a: w 40 0..
~ cr 30 ID u 0 w ,... u 20 w a: a: 0 u
10
0
125
,... 120 ....
:::> u a: w 115 0..
en !D -' ~ 110
,_ ,... iii z 105 w 0
>-a: 0 100
95 10 15 20 5 10 15 20
CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT
VARIATION OF FIELD IN-PLACE CBR AND DENSITY WITH WATER CONTENT
SECTION 2- 450-PSI SHEEPSFOOT ROLLER- 9 PASSES
"T1 C) c ::0 ,..,
... z w 1.)
!>0
~ 40 n.
~
a: Ill 1.)
0 w ... 1.) w a: a: 0 1.)
30
20
10
0
t 120
:> 1.)
a: w Q.
"' Ill ...J
115
110 ~
>... iii 10!> z w 0 ,.. g 100
DEPTH 3"
... z w 1.) a: 40 w n.
~ a: 30 Ill 1.)
0 w t; 20 w a: a: 0 1.) 10
0
... 120 "-:> 1.)
f5 115 0.
"' Ill ...J
~
>...
110
iii 10!> z w 0
>-:5 100
10 I!> 20
... z
~ 40 w 0.
~ a: Ill 1.)
0 w t; w a: a: 0 1.)
30
10
0
... 120 "-:> 1.)
5 115 Q.
"' Ill ...J
110 ~
>... ~ 10!> w Cl
,.. g 100
9!> !> 10 I!> 20
95~~~5~~~~~~10~~~~~~15~~~~~~2~0
WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT
NOTES: WATER CONTENT VALUES USED IN CBR liS WATER CONTENT PLOTS WERE OBTAINED FROM DISTURBED SAMPLES TAKEN IMMEDIATELY BENEATH CBR PENETRATION PISTON.
WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT VS DENSITY PLOTS WERE OBTAINED FROM UNDISTURBED VOLUMETRIC SAMPLES TAKEN IMMEDIATELY ADJACENT TO CBR TEST
VARIATION OF FIELD IN-PLACE CBR AND DENSITY WITH WATER CONTENT
SECTION 6- 1,500-LB WOBBLE-WHEEL LOAD-6 COVERAGES
., C) c ;:o M
60
50 1-z w u IX w 40 Q.
~ IX 30 m u 0 w 1- 20 u w IX a: 0 u
10
0
125
1- 120 .... :> u a: 115 w Q.
Ill ., ..J 110 ~ > 1:: Ill 105 z ~ >-a: 100 0
95
NOTES:
DEPTH 3" 60
50 1-z w u IX 40 UJ Q_
3: IX 30 m u 0 w t- 20 u w IX a: 0 u 10
0
125
1- 120 .... :> u IX 115 w Q.
II) ., ..J
110 ~ >-t-in 105 z w 0
> IX 100 0
5 10 15 95
20 5 WATER CONTENT IN PERCENT DRY WEIGHT WATER
WATER CONTENT VALUES USED IN CBR VS WATER CONTENT PLOTS WERE OBTAINED FRO"' DISTURBED SA ... PLES TAKEN I"'"'EDIATELY BENEATH CBR PENETRATION PISTON.
WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT vs DENSITY PLOTS WERE OBTAINED FRO"' UNDISTURBED VOLU ... ETRIC SA ... PLES TAKEN I"'"'EDIATELV ADJACENT TO CBR TEST.
DEPTH 12" DEPTH 24" 60
50 t-z UJ u IX UJ Q_
40
~ IX
30 Ill u 0 w t- 20 u UJ a: IX 0 u
10·
0
125
1- 120 .... :> u IX 115 w Q_
Ill Ill ..J 110 ~
>-t: II) 105 z UJ 0
>-IX 100 0
95 10 15 20 5 10 15 20
CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT
VARIATION OF FIELD IN-PLACE CBR AND DENSITY WITH WATER CONTENT
SECTION 8-20,000-LB WHEEL LOAD-4 COVERAGES
DEPTH 3" DEPTH 12" DEPTH 24" &0 60 60
~0 1-~0
1-~
1-z z z "' "' "' u u u
"' a: a:
"' 40 "' 40 "' 40 Q. Q. Q.
~ ~ ~
a: a: a: Cll 30 Cll 30 Cll 30 u u u 0 0 0 ... ... ... 1- 1-
20 1-
20 u 20 u u "' ... "' "' a: a: a: a: a: 0 0 0 u u u
10 10 10
0 0 0
125 125 125
1- 120 1- 120 120 ... 1-::>
... IL
u ::> ::> u u "' a: a: "' liS 115 115 Q. ... "' Q. Q.
"' "' "' 10 .J 10 Cll
.J .J
~ 110 "!: 110
"!: 110
>- >- >-1- t: 1-iii
"' iii z lOS z 105 z 105
"' ... ... 0 0 0
>- >- >-
"' a: a: 0 100 0 100 0 100
95 5 10 15
95 20 5 10 15 20
95 5 10 15 20
WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT
NOTES: WATER CONTENT VALUES USED IN CBR VS WATER CONTENT PLOTS WERE OBTAINED FROM DISTURBED SAMPLES TAKEN IMMEDIATELY BENEATH CBR PENETRATION PISTON.
WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT VS VARIATION OF FIELD IN-PLACE CBR AND DENSITY PLOTS WERE OBTAINED FROM UNDISTURBED VOLUMETRIC DENSITY WITH WATER CONTENT SAMPLES TAKEN IMMEDIATELY ADJACENT TO CBR TEST.
SECTION 9-40,000-LB WHEEL LOAD-4 COVERAGES
DEPTH 3" DEPTH 12" DEPTH 24" 60 60 110
50 .... 50 50 .... z .... z w z w u w u a: u a: w a: w 40 0. 40 w 40 0. 0.
!: !: !: a: a: a: en 30 en 30 en 30 u u u 0 0 a w w w .... .... 1-u 20 u 20 u 20 w w w a: a: a: a: a: a: 0 0 0 u u u
10 10 10
0 0 0
125 125 125
1- 120 t 120 .... 120 ' ... ...
::> ::> ::> u u u a: a: a: w w 115 0. 115 w 115 0. 0. ., "' "' en en ..J en ..J ..J
! 110 !: 110 !:
110
,.. ,.. !::
,.. .... 1-in en iii z 105 z 105 z 105
"' w w a a a ,.. ,.. ,..
a: a: a: 0 100 a 100 a 100
85 5 10 15 20
95 5 10 15 20
95 5 10 15 20
WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT ORY WEIGHT
NOTES: WATER CONTENT VALUES USED IN CBR VS WATER CONTENT PI..OTS WERE OBTAINED FROM DISTURBED SAMPLES TAKEN IMMEDIATELY BENEATH CBR PENETRATION PISTON.
WATER CONTENT AND DENSITY VALUES USED IN WATER CONTENT vs VARIATION OF FIELD IN-PLACE CBR AND DENSITY PI..OTS WERE OBTAINED FROM UNDISTURBED VOLUMETRIC DENSITY WITH WATER CONTENT SAMPLES TAKEN IMMEDIATELY AO.JACENT TO CBR TEST.
SECTION 9-40,000-LB WHEEL LOA0-8 COVERAGES
., C) c ::0 1""1
1\) 0
t-a z"' w"' u• a:O w"' 11.
~ a: Ill u 0 ... t-a uw "'"' 0:< a:o Olll uz
t... :> u a: w 11.
"' Ill ...1
z
:>
20
10
0
20
10
0
125
120
II!!>
110
>!: "' 105 z ... a >-a: 100 a
20 a t-W Z"' w< uo O:lll 10 w a.
~ a: 0
uw
"'"' a:< a:O a"' u~ 10
DEPTH 12"
a t-w Z.:
20
W< uo ~(/') 10 a.
~ a: 0 Ill u 0
~e 20
"'"' a:< a:O O"' u; 10
0 0
t- 120 t- 120
DEPTH 17"
... ...
:> :> ~il~8EEEilll338EEiil33~~ii~~Effi~ u u ~ w ... a. a.
~ ~
~ ~ >t-<ii 105 z w a >-~ 100
>-~ 105 z w 0 ,.. ~ 100
~ DATA AT THIS DEPTH NOT OBTAINED.
95~~~5~~~~~~10~~~~W-~1~5~~W-~~20. 95 5 10 15 20
95 5 10 15 20
WATER CONTENT IN PERCENT DRY WEIGHT
NOTE: ALL WATER CONTENT, DENSITY AND CBR VALUES SHOWN ABOVE WERE OBTAINED ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS.
WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT
VARIATION OF CBR AND DENSITY WITH WATER CONTENT ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS
SECTION 5-34,50Q-LB TRACTOR-3 COVERAGES
.., C) c ::0 f'1
1\)
DEPTH 3" 30
>- zo z::l
"'" U< ~ ~ 10 II.
~
"' ., 0 u 0 w ~ s 20
"'" 0:<( a:o 0111 u ~ 10
0
IZfl
.... IZO .. :;) u
"' ... Ill> II.
"' ., ..J
~ 110
>-'::
"' 105 z w 0
>-a: 100 0
115 5 10 15
WATER CONTENT IN PERCENT DRY WEIGHT
NOTE: ALL WATER CONTENT, DEN!.ITY AND CBR VALUES SHOWN A80VE WERE OBTAINED ON UNDISTURBED SAMPLES TAI\f:N IN C8R MOLDS.
30
>- zo zo w"' v" "'~ ~en 10
~ a: .,
0 <J
0 .... 88 20
~~ 8 ~ 10
0
IZ5
>- IZO ... :;) <J
a: w 115 II.
"' ., ..J
~ 110
>-':: "' 105 z w 0
>-a: 100 0
zo Qfl 5
WATER
DEPTH 12" DEPTH 24" 30
t- 0 20 zw
"'" v< a:O ~ U) 10
~ a: ., 0 <J
0 w t c 20
"'"' "'" a:< oo u"' ;,o
0
IZ5
>- IZO ... :;) u
"' "' 115 II.
"' ., ..J
~ 110
>-'::
"' 105 z w 0
>-
"' 100 0
10 15 zo 95 5 10 IS zo
CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT
VARIATION OF CBR AND DENSITY WITH WATER CONTENT ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS
SECTION 3-250-PSI SHEEPSFOOT ROLLER- 9 PASSES
..., G) c :;o 1"'1
1\) 1\)
30
020 ....... zx loJ<( 00 a: I/) 10 "' Q.
!: a: 0 ., 0
0 .... t; s 20 "'x ~(§ 011) oz 10
:::>
0
125
1- 120 u. :::> 0
a: 115 .... Q.
Ill Cll _J 110
!: > !: 105 II) z "' 0
> a: 100 0
95
NOTE
DEPTH 3" 30
0 20 ........ 2:.:: "'-< oo f!illl 10 Q.
! a: ., 0 0
0 .... 8~ 20 a: X a:-< oo olll z 10 :::>
0
125
.... 120 "-:::> 0
a: 115 .... Q.
II) ., _J 110
!: > ....
105 iii z .... 0
>-a: 100 0
5 10 15 20 95
5 WATER CONTENT IN PERCENT ORY WEIGHT WATER
ALL WATER CONTENT, DENSITY AND C8R VALUES SHOWN ABOVE WERE 08TAINED ON UNDISTUR8ED SAMPLES TAKEN IN C8R MOLDS.
DEPTH 12" DEPTH 24" 30
1- 20 zo tj~ a:~ :till 10
~ a: ., 0 0
0
"' 1-~f;3 20 a:x ~(§ Olll ~ 10
0
125
1- 120 "-:::> 0
a: 115
"' Q.
II) ., _J 110
!: > 1-iii 105 z .... 0
>-a: 0
100
10 15 20 95
5 10 15 20 CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT
VARIATION Of CBR AND DENSITY WITH WATER CONTENT ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS
SECTION 2-450-PSI SHEEPSFOOT ROLLER-9 PASSES
., G) c ;D fTI
N w
30
20 0 .......
z" w~ li!lll 10 w II.
~ a: 0 ID u 0
~e 20 w>< a:~ "'Ill Oz u::> 10
0
12~
1- 120 ... ;:) u a: II~ ... II.
Ill ID ..J 110 ! ,.. !: Ul z 105 ... 0
> ~ 100
9~
NOTE:
DEPTH 3" 30
0 20 ....... d wo ~~~~ 10 w Q.
~ a: 0 ID u 0
~e 20
"" ~~ gill ..,z 10 ::>
0
12!1
1- 120 ... ::> u a: 115 ... II.
Ill ID ..J
!: 110
,.. 1-iii 105 z ... 0
> a: 0 100
95 !I 10 15 20 5
WATER CONTENT IN PERCENT DRY WEIGHT WATER
ALL WATER CONTENT, DENSITY AND CIIR VALUES SHOWN AIIOVE WERE OIITAINED ON UNDISTURIIED SAMPLES TAKEN IN CIIR MOLDS.
DEPTH 12" 30
DEPTH 24"
20 0
!z~ tl~ 0::111 10 w II.
! a: 0 ID u 0 w t;B 20 w" a:~ gill uz
::> 10
0
125
1- 120 ... ;:) u a: II~ ... II.
Ill ID ..J
z 110
,.. 1-iii 105 z ... 0
> a: 100 0
95 10 I~ 20 5 10 15 20
CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT
VARIATION Of" CBR AND DENSITY WITH WATER CONTENT ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS
SECTION 6-J,Soo-LB WOBBLE-WHEEL LOA0-6 COVERAGES
DEPTH 3" DEPTH 12" DEPTH 24" 30 30 30
20 20 0
20 ,_o 0
~~ ,_..,
z"' Z:.:: ..,.: "'< 1.)~ w< uo ffitJ'I 10
uO 10 "'"' 10 oc"' ..,
a. w Q.
Q.
~ ~ ~
oc 0 0 oc 0 oc "' Ill
"' 1.) 1.) 1.)
0 0 0
"' UJO 20 ~EJ 20 t::J 20 tiw
"':<: w:.:: w"' "'< a:< oc< a:o a:O a:O O<ll Q<ll o"' uz uz 10 uz 10 :l 10 :l :l
0 0 0
125 125 125
... 120 ,_ 120 ,_ 120 ... ... "-::> :::l ::> ' 1.) 1.) 1.)
a: 115 a: 115 a: 115 .., .., w Q. a. !l.
ell <I) <I)
"' "' "' -' -' -' 110 110 110
~ ~ ~
>- >- >-,_ ,_ ,_ iii 105 iii 105 iii 105 z z z UJ UJ w 0 0 0
>- ,.. ,.. a: 100 a: 100 a: 100 0 0 0
95 95 95 5 :o 15 20 5 10 15 20 5 10 15 20
WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT
NOTE: ALL WATER CONTENT, DENSITY AND CBR VALUES SHOWN ABOVE WERE OBTAINED ON UNDISTURBED
VARIATION OF CBR AND D'ENSITY WITH WATER CONTENT SAMPLES TAKEN IN CBR MOLDS.
ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS SECTION 8-20,000-LB WHEEL LOAD-4 COVERAGES
30 DEPTH 3"
30 DEPTH 12"
30 DEPTH 24"
1-o 20 t- 0 20 t-O 20 ZUJ Zw zw
"'"' "'"' "'"' <)<( <)<( <)<(
a:o a:o o::o wUl 10 ~"' 10 :rU) 10 Q_
~ ~ ~
"' cr a:
Ill 0 Ill 0 Ill 0 <) <) <)
0 0 0 w "' "' t; 0 20 ~8 20 tJ 8 20
"'"' "'"' "'"' "'"' 0::<( a:< .,...: 0 a:o oO 00 0<1'1 u"' u"' u; 10 ; 10 ;10
0 0 0
125 125 125
t-120 t- t- 120 ... ... 120 ...
::> ::> ::> u u u
"' "' "' w a. 115 w 115 w 115
0. Q_
"' U) U) Ill _J Ill Ill
...J ...J
~ 110 ~
110 ~
110 ,.. ,.. >-~ U)
t- t-z 105 U) 105 U) 105
"' z z 0 w w
0 0 ,.. >- >-
"' 100 "' a: 0 0 100 0 100
95 95 95 5 10 15 20 5 10 15 20 5 10 15 20
WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT
NOTE. ALL WATER CONTENT, DENSITY AND CBR VALUES SHOWN ABOVE WERE OBTAINED ON UNDISTURBED VARIATION OF CBR AND DENSITY WITH WATER CONTENT SAMPLES TAKEN IN CBR MOLDS.
ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS SECTION 9-40,000-LB WHEEL LOAD-4 COVERAGES
DEPTH 3" DEPTH 12" DEPTH 24" 30 30 30
1-020 !Z 020 t-o 20 zw
~~ ~ll! tl~ V< :i~ 10 ~~10 ~5ll0 Q.
:!: :!: ~
a: a: a: CD 0 CD 0 CD 0 u u u
0 0 0 ... ... ... ...
l;jo 20 te20 :.le2o ... ~ "'"' "'"' a:< "'< 8~ :!i~ :!i~ 0 ~10 u~ 10 ~10
0 0 0
1211 1211 1211
... 120 ... 120 ... 120 ... ... ... :;) :;) :> u u u a: a: 1111
a: 115 .. 11!1 "' ...
Q. ... Q. .., II) II)
II Ill Ill ...1 .J .J
! 110 :!: 110
~ 110
> > >-... ... ... w; 10!1 iii 10!1 iii 105 z z z .. "' ..
0 0 0
> >- >-a: 100 a: 100 a: 100 0 0 0
8!1 !I 10 I !I 20
8!1 5 10 15 20
9!1 5 10 15 20
WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DRY WEIGHT
NOTE: ALL WATER CONTENT, DENSITY AND CBR VALUE$
VARIATION OF DENSITY !HOWN AIIOVE WERE OBTAINED ON UNDISTURBED CBR AND WITH WATER CONTENT SAMPLE$ TAKEN IN CBR MOLDS.
ON UNDISTURBED SAMPLES TAKEN IN CBR MOLDS SECTION 9-40p00-LB WHEEL LOAD-8 COVERAGES
.., G) c ;o fTI
1-z ... u a: ... Q.
; a: Ill u
Q ... t ... a: a: 8
20
Q 10 ... " c 0 .,
0
30
0 ... 1- 20 u ~ :ll 0 1.) 10
Cl)
c
0
12S
... ""120 :J u
a: ~II!;
Cl) ID .J
110 !; ,. 1-iii lOS z ... Q
,. a: 100 Q
9S
-
~
FIELD IN-PLACE TESTS 20
10 Q ......
Z" ... ~ ~CI) 0 ... Q.
~
a: 30 ID u Q
~ fl2o Ul-lo.ll.)
:f~ 0:1; uo 10
u
"' c
5 10 o5 05
12S
1- 120 ... ;) 1.)
15 115 Q.
., ID .J 110 ; ,. 1-iii lOS z ... Q
,. a: tOO Q
95 5 10 IS s
LEGEN{2 34,SOO·LB TRACTOR - 3 COVEP.AGES ZSO•PSI SHEEPSFOOT ROLLER -9 PASSES 450-PSI SHEEPSfOOT ROLLER -9 PASSES STD. AASHO EI'FORT MOO. AASHO EfFORT 2,000-PSI STATIC PRESSURE 1,500-LB WOBBLE-WHEEL LOAD- 6 COVERAGES ZO,OOO·LB WHEEL LOAD- 4 COVERAGES 40,000-LB WHEEL LOAD- 4 COVERAGES
CYLINDER TESTS FIELD IN-PLACE TESTS CYLINDER TESTS 20 20
.
Q 10
Q 10
. ...... ... ... Z" z" ... ~ ...~ l;?., li?CI) 0 0 ... "' Q. Q.
!; z a: 30 30 a: Ill Ill u u Q Q
~ ~20 ~~20 ....... Ut-a:U "'u a:~ a:c a: a. 0::~; 0::1;
' u 0 10 uo 10
u u Cl) ., . c c
10 I!; 05 10 15 05 10 15
125 12!;
IZO IZO ... ... ... ... :;;)
u :;;)
a: II 5 1.) liS a: .... .... -...: II. Q. ..
"' ., ~ 110 ~ 110
; ! ,. ,. t:1os Cl) ~lOS z z .... .... Q Q
i'i1oo ~ 100 Q Q
9S 9S 10 IS s 10 IS s 10 IS
WATER CONTENT IN PERCENT ORY WEIGHT
NOTE: I'IELO DATA SHOWN ARE FOR TESTS AND SAMPLES TAKEN IZ INCHES BELOW TOP OF
AND COMPACTED FILLS. COMPARISON Of FIELD LABORATORY COMPACTION AND CBR
, C) c ;:o Pl
1\)
(X)
<I)
a.
~
I:
~
25
~ 20
Iii ~
0 10 u 0 ... z ;;:: z 0 u z :::>
1-...
0
120
:::> 115 u a: "' 0.
110 <I) Ill .J
z ,.. 1-iii z
105
~ I 00 ,.. a: 0
34,000-LB TRACTOR
10 15 20 WATER CONTENT IN PERCENT DRY WEIGHT
NOTES: TESTS PERFORMED ON 211
BY 411
SPECIMENS CUT FROM UNDISTURBED TEST PIT SAMPLES. ALL SPECIMENS TESTED AT THE IN-PLACE WATER CONTENT AND DENSITY.
<I) a. z I: 25 I-
" z w a: 20 Iii
0 ... z ;;: z 0 u z :::>
1-...
0
120
a 115
a: ... 0.
<ll II 0 Ill .J
!: 105
250-PSI SHEEPSFOOT 450-PSI SHEEPSFOOT ;;; 30 0.
~
I: 25
1-.., z "' a: 20 1-<I)
w > iii 15 <I)
"' a: 0. ::ll 0 10 \J
0 w z
5 ;;: z 0 u z :::> 0
125
12 0
1-"-:::> 115 u a: w a. <I)
II 0 ., .J
~ 105
>-1-iii z w .oo 0
>-a: 0
955 ~=·-iii
: 100
1155 10 15 20 10 15 20
WATER CONTENT IN PERCENT DRY WEIGHT WATER CONTENT IN PERCENT DFiY WEIGHT
VARIATION OF UNCONFINED COMPRESSIVE STRgNGTH AND DENSITY WITH WATER CONTENT
UNDISTURBED SAMPLES
., G) c ::0 f11
1\) co
1500-LB WOBBLE WHEEL ROLLER 20,000-LB WHEEL LOAD AFTER 4 PASSES 40,000-LB WHEEL LOAD AFTER 4 PASSES 40,000-LB WHEEL LOAD AFTER 8 PASSES
~ Q.
:I: tCJ z UJ
30
a: 20 lii w > iii 15
"' w a: Q.
~ 10 \)
0 w z 5 t;: z 8 z ::> 0
125--
t-120 ' ...
_j 110 z
>-1-iil1o.; z "' 0
>-15100
10 15
"' Q.
~
:I: t-CJ z w a: 1-
"' w > iii
"' w a: Q_
::!: 0 \)
0 w z t;: z 0 \) z ::>
25
20
I~
10
5
0
125
t 120
::> \)
a: 115 "' Q.
~ Ill _J 110
~
>-1-
~105 w 0
>-15100
95 5
NOTES' TEST PERF"ORMED ON 2' BY 411
SPECIMENS CUT FROM UNDISTURBED TEST PIT SAMPLES.
ALL SPECII\4€NS TESTED AT THE IN-PLACE WATER CONTENT AND DENSITY.
'
10 15 WATER CONTENT IN
~ ~ ~ ~
~ ~ 25 25
I I 1- t; CJ z z w w a: 20 a: 20 1- tii "' w w > 15 > 15 iii iii ~ "' w w a: a: Q. Q. ::!:
10 ::!: 10 0 0 \) \)
0 0 w "' z 5 ~ 5 t;: "-z z 0 0 \) \)
z z ::> 0 ::> 0
125 125
t;:l20 t;:120
::> ::> \) \)
:5 115 ~ 115 Q. Q.
"' ~ Ill Ill _j _j
110 110 ~ ~ >- >-1- 1-
~ 105 ~105 w "' 0 0
>- >-15100 ~100
95 95 5 10 15 5 10 15
PERCENT DRY WEIGHT
VARIATION OF UNCONFINED COMPRESSIVE STRENGTH AND DENSITY WITH WATER CONTENT
UNDISTURBED SAMPLES
...... (;) c ;o f'T1
w 0
30 ;; ... ~ %
~ .. at: t;
20
.. > Oi .. 1& .. at: ... 2 8 10
Q .. z ;;: z 0 u z ~ 0
... 120 ... a at: ~ 11!1
~ ! 110
... ... Oi z 10&
:!: ,.. ! 100
.. Q.
z % 25 ... " z :1! 20 t; .. > ~ 1!1
"' at: ... 2 0 10 u 0
"' z ;;:
~ ::> 0
1- 120 ... ::> 0
a: ~ 115
~ .J
! 110
... 1-
~ 105
"' 0 ,.. at: 0 100
& 10 15 20 WATER CONTENT IN PERCENT ORY WEIGHT
"' > :: 15
"' a: Q.
2 8 10
0
"' z .. z 0 0 z ::> 0
... 120 ... :::l 0
a: "' 115 Q. .. II) .J
z 110
... .... iii z 105
"' 0
lr 0 100
5 10 15 20 WATER CONTENT IN PERCENT DRY WEIGHT
5 10 15 20 WATER CONTENT IN PERCENT DRY WEIGHT
WATER CONTENT VS DENSITY AND UNCONFINED COMPRESSIVE STRENGTH
LEGEND
WATER CONTENT VS DENSITY AND UNCONFINED COMPRESSIVE STRENGTH
WATER CONTENT VS DENSITY AND UNCONFINED COMPRESSIVE STRENGTH
~--~-~-.--
D----
34,500-LB TRACTOR -3 COVERAGES 250-PSI SHEEPSFOOT ROLLER-II PASSES
45Q-PSI SHEEPSFOOT ROLLER-9 PASSES l,&oo-LB WOBBLE-WHEEL LOAD-II COVERAGES 40,000-LB WHEEL LOAD-4 COVERAGES 40,000-LB WHEEL LOAD·& COVERAGES
MODIFIED AASHO STANDARD AASHO
VARIATION OF UNCONFINED COMPRESSIVE STRENGTH AND DENSITY WITH FIELD COMPACTION EQUIPMENT