Aggregate Strength

8/12/2019 Aggregate Strength

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INVESTIGATION OF TESTING METHODS TO DETERMINE LONG-TERM

DURABILITY OF WISCONSIN NATURAL AGGREGATE RESOURCES

GREGORY S. WILLIAMSONGraduate Student in Civil and Environmental Engineering, Virginia Polytechnic Institute and State University

Blacksburg, VA, USA

RICHARD E. WEYERS, Ph.D.Professor in Civil and Environmental Engineering, Virginia Polytechnic Institute and State University

Blacksburg, VA, USA

DAVID W. MOKAREM, Ph.D.

Research Scientist, Virginia Transportation Research Council

Charlottesville, VA, USA

DANIEL S. LANE

Research Scientist, Virginia Transportation Research Council

Charlottesville, VA, USA

ABSTRACT

The Wisconsin Department of Transportation (WisDOT) uses approximately 11,000,000

tons of aggregate per year for transportation projects. Therefore, being able to select durable

aggregates for use in transportation projects is of considerable importance. If the aggregate

deteriorates then the constructed facility will require premature repair, rehabilitation or

replacement. Realizing the importance aggregate durability and also those deficiencies in the

current WisDOT testing protocol may exist, it has been concluded that the durability-testing

protocol for Wisconsin aggregates needs to be updated.

This project has identified recent advances in the understanding and testing of aggregate

durability. An in depth literature review was conducted and from the compiled information a

laboratory testing program was developed.

From the test results it was found that the WisDOT aggregate testing protocol could be

reduced substantially by eliminating many of the testing requirements for aggregates that have

vacuum saturated absorptions of less than 2%. The Micro-Deval abrasion test is recommended

for inclusion in WisDOT testing protocols as a test to measure the abrasion resistance of

aggregate while the L.A. Abrasion test is better suited as a measure of aggregate strength.

Additional conclusions were made based on the durability testing conducted and an overall

testing protocol was developed.

Keywords: aggregate, durability, soundness, abrasion resistance, aggregate strength

Williamson, Weyers, Mokarem, and Lane 1


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INTRODUCTION

Aggregate is the most fundamental component of construction. It is used as an unbound

or lightly bound material in base courses and as a bound material in bituminous and Portland

Cement Concretes (PCC). Aggregate constitutes in excess of 90% of the volume of base courses

and bituminous concrete and 60 to 80% of the volume of Portland cement concrete. Aggregate

is exposed to a number of physical and chemically degrading forces during processing,

transporting, and construction as well as during the constructed facilitys life. As the main load-

carrying component of unbound, bituminous concrete, and Portland cement concretes, if the

aggregate fails, the facility fails to perform its design intent.

Durability is a term used to define resistance to the chemical and physical forces of

degradation to which a material is subjected throughout its service life. Given WisDOTs

investment in its transportation infrastructure, it is important that the aggregate testing protocol

be appropriate for the assessment of the long-term durability of constructed facilities. An ideal

protocol would neither accept non-durable materials nor reject sufficiently durable materials.

To ensure the durability of pavements and structures, WisDOT has used a number of test

methods to assess aggregate quality and durability. The test methods include gradation,

plasticity, resistance to abrasion (impact), soundness, and freezing and thawing resistance. Some

of the tests have been developed as aggregate quality assurance tests and others have been

borrowed from other materials testing programs. These tests have been in use for well over 50years and for the most part have served the highway industry well. However, these tests were

developed when high quality natural sources of aggregate were abundant and social and political

pressures on the use of industrial by-products and recycled/reclaimed materials were nonexistent.

In addition, some of these tests have been kept in use in the name of tradition and simplicity

rather than being replaced by other methods based on our ever-increasing understanding of the

science of aggregate durability. In light of these changes and advances in technology, WisDOT

sponsored a project to assess the adequacy of its aggregate testing protocol

BACKGROUND

The following discussion is presented to illustrate the underlying philosophy that was

used to develop the WisDOT aggregate durability testing protocol.



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WisDOT projects use aggregates as unbound pavement base courses, bituminous and

PCC pavements and structural concretes for bridges, box culverts, and retaining walls. Each one

of these facility components is exposed to a set of chemical and physical degrading forces during

construction and throughout the facilitys service life. For example, structural Portland cement

concrete aggregates are exposed to:

Abrasive forces while the aggregate is in a moist/wet state during stock piling,

transporting, batching, mixing, and placing of the concrete,

Tensile, shear, and compressive stresses during loading of the reinforced concrete

structure,

Chemical environments of a saturated solution of calcium hydroxide, sodium and

potassium hydroxide, and sulfates in the concrete,

Wetting and drying cycles of the concrete, and

Temperature changes including freezing and thawing of absorbed moisture of the

concrete.

With respect to temperature changes, an unconfined aggregate must be capable of

handling the stresses that are developed due to water freezing within the aggregate pore

structure. During the freezing of saturated aggregates bound together by Portland cement paste,

the pressure being created by the freezing water must not be sufficient to fracture the aggregate

nor be extruded into the surrounding cement paste at a rate which fractures the cement paste

(1). Of these three potential aggregate freezing and thawing destructive mechanisms, two are

related to the aggregate being bound within cement paste. An unbound aggregate test such as

soundness or the freezing and thawing test would not assess these aggregate performance related

aspects. This may be the reason why these tests have been poor predictors of the freezing and

thawing durability of certain aggregate types. It is noteworthy that the expulsion distance

mechanism may become more important in the future as more low permeable concretes are

produced which have denser aggregate-paste transition zones.

The above could be interpreted that it is necessary to test all concrete aggregates exposed to

freezing and thawing under saturated conditions in a concrete freezing and thawing test. This

will not be necessary because an aggregate with porosity below 0.3% produces expansions

within the elastic limits of the aggregate and surrounding cement paste (1). Thus, a concrete



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aggregate protocol may consist of a simple, precise test for water absorption and saturated

specific gravity to identify the very good and very poor aggregates and a freezing and thawing or

surrogate test for marginal aggregates.

However, since the freezing and thawing of base courses takes place in the unbound state,

the soundness test may be sufficient if the lack of precision aspects of this test can be addressed.

Also, PCC pavement aggregates need to be assessed for the propensity of D-cracking (durability

cracking), a somewhat different freezing and thawing property (2). D-cracking is cracking that

occurs along the edges or at the corners of concrete slabs due to the expansion of non-durable

coarse aggregates during freezing and thawing. The resulting deterioration is crescent shaped

cracks or spalls in the concrete.

Thus, the developed aggregate durability testing protocol is based on construction-service

life performance criteria. The protocol is then based on performance tests, which will

realistically simulate the field exposure and degradation process (3).

EXPERIMENTAL METHODS

Aggregate Performance Assessment Program

Aggregate performance durability issues may be categorized as physical or chemical.

Physical degradation mechanisms include:

Attrition during handling and construction,

Degradation under in-service loads, and

Environmental degradation from freezing and thawing, wetting and drying, and/or

thermal expansion and contraction.

Chemical degradation mechanisms include the following but are not assessed in this study:

Reactive oxides as CaO and MgO and sulfides as ferrous sulfide,

Alkali-silica reaction, and

Alkali-carbonate reaction.

Aggregate performance properties have a direct influence on the stability of aggregate

particles in the unbound and bound state. For example, an aggregate with a high porosity and

low permeability defines the aggregates freezing and thawing critical size whether in the



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unbound state or the bound state. An aggregate with a high porosity and high permeability may

not fracture as an unbound material but will degrade the binding forces in bituminous and PCC.

Thus, aggregate performance properties not only influence aggregate durability, but also the

durability of their inclusion material. Therefore, the proposed aggregate testing program is

presented for unbound, and bound aggregate such as bituminous concrete, PCC pavement, and

structural elements and their associated durability performance parameters.

Aggregate Physical Properties

Aggregate physical durability properties are typically inter-related. For example, both

freezing and thawing degradation mechanisms, aggregate fracture and degradation of binder-

aggregate forces occur when the aggregate has a high porosity. Porosity and absorption are

directly related, as are absorption and specific gravity. Aggregate that has a high specific gravitygenerally has a low absorption. These aggregates would generally have a high strength, high

abrasion resistance, and a high resistance to dimensional changes. Relative to physical

degrading forces, some aggregates may be accepted based on specific combinations of specific

gravity and absorption. The physical performance characteristics of other aggregates may have

to be determined by abrasion, strength, and freezing and thawing testing. Thus, the objective of

the proposed testing program is to develop a tiered aggregate assessment protocol.

Aggregate Chemical Properties

While aggregate physical durability properties are generally inter-related, chemical

degradation mechanisms are typically dependent upon the mineralogical composition of the

aggregate. WisDOT officials have determined that chemical degradation mechanisms relating to

aggregate mineralogy are not a significant problem in Wisconsin. Therefore, the proposed

testing protocol does not contain any chemical durability testing.

LABORATORY TESTING

Current WisDOT Testing Protocol

WisDOTs current aggregate durability testing protocol is presented below in Table 1:



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Aggregate Test Selection

Selection of the tests was based upon the tests precision, repeatability, efficiency, and

predictive capabilities. Wisconsins current aggregate tests were also conducted for comparative

purposes. The tests selected were as follows:

Lightweight Pieces in Aggregate (ASTM C 123-98) (4)

Vacuum Saturated Specific Gravity and Absorption (Coarse)(Modified - ASTM C 127)

Sodium Sulfate Soundness (ASTM C 88) (4)

Frost Resistance of Aggregates in Concrete (ASTM C 666) (4)

Unconfined Freezing and Thawing of Aggregate (CSA A23.2-24A) (5)

Micro-Deval Abrasion (Coarse) (AASHTO TP 58) (7)

L.A. Abrasion (ASTM C 131-01) (4)

Aggregate Crushing Value (British Standard 813-Part 3) (6)

Crushed stone and gravel aggregates were all subjected to the same testing protocol. The

use of the same testing procedures for all sources will increase efficiency and will also

encompass the full spectrum of durability testing needs. Testing for Lightweight Pieces in

Aggregate is an important screening test used to determine the percentage of non-durable

aggregates for crushed stone and gravel samples, as excessive amounts of lightweight aggregate

will result in a reduction in durability. The test for Vacuum Saturated Specific Gravity (VSSG)

and Absorption (VSA) may be used as an indicator for aggregate soundness. VSSG and VSA

testing was selected in place of standard SG and absorption testing because it is a better predictor

of the long-term absorptions of aggregate in the field. Soundness tests that were investigated

were the Sodium Sulfate Soundness (ASTM C88), Unconfined Freezing and Thawing of

Aggregates (CSA A23.2-24A), and Frost Resistance of Aggregates in Concrete (ASTM C 666)

tests.

Unconfined Freezing and Thawing of Aggregate (CSA A23.2-24A) testing was carried out inplace of Soundness of Aggregates by Freezing and Thawing (AASHTO T 103) because it was

recommended over AASHTO T 103 and the Sulfate Soundness Test by Senior and Rogers (8).

The test has better precision and better correlation with field performance, which are among the

reasons cited for its recommendation. Additionally, the Canadian test requires only 5 freezing

and thawing cycles in comparison to the 25 required by AASHTO T 103.



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Testing of the resistance of aggregates to abrasion was conducted using both the L.A.

Abrasion test and the Micro-Deval test. The Micro-Deval test was selected because it can be

applied to both fine and coarse aggregates, and recent reports have shown that test results

correlate better with field performance records (9, 10, 11). Also, the L.A. Abrasion and Impact

Test includes the effects of impact on the aggregate sample, thus both the effects of abrasion and

impact are present in the test results. As a result, brittle aggregates may have a higher L.A.

Abrasion loss do to the impact forces in the test. There is no clear understanding on how to

interpret the results so that mass losses of the aggregate sample can be attributed to the abrasion

resistance or the impact resistance of the aggregate. If the Micro-Deval test is used, another test

must also be used to measure the aggregate strength. The British Aggregate Crushing test and

the L.A. Abrasion test have been chosen to assess the strength of the aggregate.

Although, not included in the testing program, aggregates which may be alkali carbonate

or alkali silica reactive are to be tested in accordance with ASTM C 1293 (Determination of

Length Change of Concrete Due to Alkali-Silica Reaction) (4). This recommendation is based

on the results of the literature review (12).

Laboratory Testing Program

Seventy natural aggregate samples, representing the full range of aggregate available in

Wisconsin, were collected for testing. Initially all 70 crushed stone and crushed gravel samples

were tested for VSSG and VSA in a test procedure similar to ASTM C 127. The modification

was to place the aggregate under a vacuum of 635 mm (25 in.) of mercury for 5 minutes prior to

saturating the aggregates. Aggregate saturation consisted of the introduction of tap water while

the aggregate was under vacuum and subsequent submersion in water for 24 +/- 1 hour. From

these results 30 aggregates were selected for further analysis throughout the range of the VSA

values. The selected aggregates were then subjected to the full suite of selected tests with one

exception. Only nine aggregates were tested in concrete for freezing and thawing durability

using ASTM C 666-97 (Resistance of Concrete to Rapid Freezing and Thawing) due to limited

time and resources. ASTM procedure C 666-97 was modified to 28 days of curing in lime

saturated water rather than the 14 days specified and the aggregate was saturated by soaking it in

water for 24 hours prior to the mixing of the concrete. These modifications were carried out to



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ensure complete saturation of the aggregate prior to freezing and thawing testing. This is

intended to simulate the worst-case field condition.

Selection of Aggregates

With the assistance of WisDOT officials, 70 natural aggregate samples were selected for

testing from across the state. Among the aggregates tested were unconsolidated deposits and

bedrock from different geologic groups. A variety of glacial deposits were tested because the

material often varies widely depending upon from which direction the depositing glacier

originated. It was also important to test bedrock from groups with good and poor field

performance ratings. The performance ratings of poor, intermediate, and good were based on

either field performance or test results. The performance ratings were designated by WisDOT

officials and should be verified due to their subjective nature. Figure 1 presents the sample sitelocations throughout the state of Wisconsin for both the pits and quarries.

The importance of testing the range of aggregate durability performance based on field

performance ratings cannot be over emphasized. It is often very easy to identify good and poor

performing aggregates based on laboratory test results. It is much more difficult to identify

aggregates that have adequate field performance histories but would be classified as intermediate

aggregate based on laboratory testing.

For the 30 aggregate samples that were selected for further testing it was important to

ensure that the full range of aggregate qualities was reflected in the sample set with an emphasis

on intermediate quality aggregates. The distribution of the aggregate samples tested was as

follows: 7 Poor, 13 Intermediate, and 10 Good

Once the sample distribution had been determined, the individual samples within the

performance categories were selected based on VSA data, as there is a strong relationship

between VSSG and VSA. Aggregates with low, moderate, and high absorption values were

selected from each group in order to be certain that aggregate qualities can be identified without

any dependence on absorption i.e. a poor aggregate with a low absorption can be identified as

poor just the same as a poor aggregate with a high absorption.



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TEST RESULTS

Vacuum Saturated Specific Gravity and Absorption

VSSGs and VSAs were determined for all 70 natural aggregate samples using the

modified version of ASTM C 127. VSA was then plotted against VSSG to investigate the

relationship (see Figure 2). The use of the VSA as a preliminary durability indicator will be

investigated in comparisons with other test data. As shown, there is a general linear relationship

between VSA and VSSG for carbonate rocks. The relationship was not investigated for

igneous/metamorphic rocks because of their tendency to have low absorptions regardless of

specific gravity. The siliceous granites and metamorphic aggregates have lower VSAs and

VSSGs and are shown with VSAs of about 1% and VSSGs ranging between 2.55 and 2.65.

Lightweight Particles in Aggregate

The percentage of lightweight particles in aggregate was determined using WisDOT

modified ASTM procedure 123-98. The ASTM procedure was modified to test only coarse

aggregate material retained on the 3/8 in. sieve. WisDOT sets a limit of 5% and 2% chert, with a

SSD specific gravity of less than 2.45, by mass for standard concrete and pre-stressed concrete,

respectively. Chert is a white or buff colored siliceous material that is highly porous and non-

durable. Freezing and thawing deterioration caused by chert tends to manifest itself in the form

of popouts. The percentages of chert were determined by petrographic analysis from those

aggregate samples that contained lightweight material (See Table 2).

L.A. Abrasion

L.A. Abrasion tests were performed using 500 revolutions in accordance with ASTM C

131-01. Figure 3 presents the relationship between L.A. Abrasion and VSA. The failure limits

are shown as solid lines. The dashed line represents the range for which all L.A. Abrasion values

will lie for VSAs of less than 2%.

As demonstrated, aggregate with VSAs of less than 2% will have a L.A. Abrasion value

of less than 35%, which is substantially lower than the 50% loss failure criterion used by

WisDOT. It should be noted that only one aggregate had a L.A. Abrasion value of greater than

50%.



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Micro-Deval

Figure 4 presents the relationship between VSA and Micro-Deval % loss. A loss of 18%

was used as the failure criterion as recommended by Kandhal and Parker for HMA (13).

As demonstrated, a failure limit of 18% may be too stringent and a limit of 25-30% may

be more appropriate for Wisconsin aggregate. Also, for aggregate with VSA less than 2% only

one has a % loss greater than 12%. Therefore, it is reasonable to conclude that aggregate with

VSA less than 2% will have a low Micro-Deval value.

Aggregate Crushing Value

Figure 5 presents the Aggregate Crushing Values of the aggregates tested with respect to

VSA. The British Standard suggests that the allowable aggregate crushing loss should be based

on the parent material. Average losses range from 16% for igneous material to 27% for

argillaceous limestone.

With no discernable relationship or recommended failure criteria it is not possible to

draw any conclusions from this data. However, for aggregates with a VSA of less than 2%, the

Aggregate Crushing Value is less than 22%.

Strength and Abrasion Test Comparison

A comparison of L.A. Abrasion and Micro-Deval test results demonstrated that there is a

linear relationship although not a strong one (See Figure 6). Thus, it can be reasoned that the

two tests are measuring different aggregate properties.

Figure 7 presents the relationship between L.A. Abrasion and Aggregate Crushing Value.

As shown, the two tests have a distinct correlation implying that the L.A. Abrasion test is more a

test of aggregate strength than of abrasion resistance. The results indicate that it may be

necessary to perform both the L.A. Abrasion Test and the Micro-Deval Test or possibly the

Micro-Deval and Aggregate Crushing tests.

The Micro-Deval, Aggregate Crushing Value, and L.A. Abrasion test results demonstrate

that the tests are measuring different physical properties of the aggregate. The Micro-Deval Test

measures the abrasion resistance of the aggregate while the L.A. Abrasion and Aggregate

Crushing Value measure strength.



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Sodium Sulfate Soundness

Figure 8 presents the relationship between VSA and sodium sulfate soundness loss with a

failure criterion of 12% loss, which is currently being used by WisDOT. There is no apparent

correlation between the two data sets.

As shown aggregates with VSA of less than 2% will have sulfate soundness losses of less

than approximately 5%. It should also be noted that the soundness test was only able correctly

identify 2 out of the 7 poor aggregates tested.

Unconfined Freezing and Thawing

Unconfined Freezing and Thawing of Aggregate tests were conducted in accordance to

Canadian Standard A23.2-24A. The failure criterion is a 10% loss after five cycles of freezing

and thawing, as stated in the Canadian Standards Association specification. Figure 9 presents the

relationship between VSA and freezing and thawing loss.

There is no apparent relationship between VSA and unconfined freezing and thawing

loss. A full third of the aggregates tested were greater than the failure limit of 10%. Present

WisDOT specifications for unconfined freezing and thawing limit the loss to 18% for AASHTO

T 103, which is similar to the Candian Freeze/Thaw test. Thus, a 15% loss limit appears to be

reasonable.

Freezing and Thawing in Concrete

The freezing and thawing of concrete specimens containing Wisconsin aggregate was

conducted in accordance with ASTM C 666 (Resistance of Concrete to Rapid Freezing and

Thawing). The failure criterion for ASTM C 666 is a reduction in the fundamental transverse

frequency of greater than 40%. Due to time constraints only 9 of the 30 aggregates were tested.

The aggregates selected for testing represented all three performance categories with samples

having low, moderate, and high absorptions. Of the nine aggregate samples tested, none failed.

The poorest performing aggregate reflected a 30% reduction in transverse frequency. It is useful

to note, however, the deterioration that occurs throughout the test. Those aggregate samples

containing chert resulted in more popouts in the concrete specimens, which is generally more of

an aesthetics concern rather than a structural problem. It may be necessary to conduct freezing

and thawing in concrete tests where lightweight aggregate particles are a concern because one



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aggregate, sandstone containing in excess of 16% lightweight aggregate, disintegrated during

the testing and left voids in the concrete where the aggregate once was.

CONCLUSIONS AND RECOMMENDATIONS

1. The absorption of an aggregate, while not directly related to the quality of the aggregate, can

still be used as a preliminary indicator of durability. Aggregates with vacuum saturated

absorptions of less than 2% do not need to be tested for L.A. Abrasion loss, Micro-Deval

loss, Unconfined or Confined Freezing and Thawing tests. They will still, however, need to

be tested for Lightweight Pieces in Aggregate.

2. The inclusion of ASTM C 123 (Lightweight Pieces in Aggregate) in the WisDOT aggregate

durability testing protocol is necessary in order to quantify non-durable lightweight material

percentages. This is important particularly for gravel resources where high variability inparent material is common. The WisDOT pre-established maximum allowable chert

percentages of 5% for normal concrete and 2% for pre-cast concrete are appropriate.

However, rather than specifying only chert with a SSD specific gravity of less than 2.45, it

would be best to limit all lightweight aggregate to 5%, and test those aggregates that fail in a

confined freezing and thawing test. For concrete structures where aesthetics are a concern

there should be no chert present in the aggregate to prevent popouts from occurring.

3. The L.A. Abrasion test was only able to identify the very worst aggregate sample as being

poor. This indicates that the L.A. Abrasion test does have some ability to predict

performance. From this data it can be concluded that the L.A. Abrasion test cannot directly

predict the overall performance of an aggregate, but it can accurately estimate a key

parameter, aggregate strength. The L.A. Abrasion test should continue to be used to evaluate

aggregate strength. Realizing that the Aggregate Crushing Value measures this same

parameter, it is not recommended that the Aggregate Crushing Value test be implemented at

this time.

4. The Micro-Deval test (AASHTO TP 58) with the recommended maximum allowable loss

limit of 18% rejects nearly 50% of all aggregates tested. It is clear, however, that more poor

aggregates are accurately classified than with the L.A. Abrasion test. For Wisconsin

aggregate it appears that a maximum allowable loss limit of 25% is more reasonable. The

Micro-Deval test should be added to WisDOT testing protocol to evaluate the abrasion



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resistance of aggregate, as this test more accurately models the degradation that occurs

during handling and mixing.

5. The Sodium Sulfate Soundness test (ASTM C 88) was able to correctly identify two out of

seven poor aggregates without rejecting any intermediate or good aggregates. The problem

with this test is that it is highly variable with a potential multi-laboratory difference between

two tests of 116%.

6. The Unconfined Freezing and Thawing test (A23.2-24A) data has no correlation with

Sodium Sulfate Soundness results. Due to the poor precision of the sodium sulfate test, it is

recommended that the unconfined freezing and thawing test be included in the WisDOT

aggregate testing protocol with an upper limit of 15% loss.

7. The Freezing and Thawing of Concrete test is recommended for aggregate that are to be used

in the bound state. This test helps to identify non-durable aggregates that may result in

popouts, aggregate deterioration, and cracking of concrete.

PROPOSED TESTING PROTOCOL

Based on the conclusions presented above proposed testing protocols have been

developed for unbound and PCC aggregates and are presented in Figures 10 and 11, respectively.

The testing protocols were developed with the aim of improving the aggregate durability testing

program while also reducing the amount of testing required. The results of the proposed testing

protocol in comparison with current WisDOT testing protocol are presented in Table 3. The

proposed testing protocol rejected more of the poor performing aggregate samples while

rejecting fewer good samples. Additionally, by using the proposed testing protocols the required

L.A. Abrasion testing can be reduced by 37% and the Unconfined Freezing and Thawing testing

can be reduced by 30% for the 30 aggregate samples tested.



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REFERENCES

1. Verbeck, G. and R. Landgren, Influence of Physical Characteristics of Aggregate on

Frost Resistance of Concrete, Proceedings, ASTM, Vol. 60, pp. 1063-1079.

2. Dubberke, W. and V. Marks, The Relationship of Aggregate Durability to TraceElement Content, Interim Report on Project HR-266, Iowa DOT, p. 12, Jan.

1984.

3. Frohnsdoff, G. and J. Clifton, Cement and Concrete Standards of the Future,

Workshop on Cement and Concrete Standards Report, NIST, p. 48, Oct. 1995.

4. ASTM, Annual Book of ASTM Standards. Vol. 04.02, ASTM, Philadelphia, PA,

2002.

5. CSA, Canada Materials and Methods of Concrete Construction/Methods of Test forConcrete: National Standards of Canada, CSA-A23.1-00 and CSA-A23.2-00,

August 2001.

6. British Standard, Testing Aggregates Part 110: Methods for determination of

aggregate crushing value (ACV), BS 812-110 1990, 1998.

7. AASHTO, 2000, Standard Specifications for Transportation Materials and Methods

of Sampling and Testing. Part II Tests: 1136.

8. Senior, S. A. and Rogers, C. A., 1991-2, Laboratory Tests for Predicting CoarseAggregate Performance in Ontario, Transportation Research Record 1301,

Washington, D.C.

9. Folliard, K.J. and Smith, K.D., 2003, Aggregate Tests for Portland Cement Concrete

Pavements Review and Recommendations. National Cooperative Highway

Research Program, Research Reports Digest No. 281, Transportation Research Board,

Washington, D.C.

10. Kandhal, P.S., and Parker, F., 1998, Aggregate Tests Related to Asphalt ConcretePerformance in Pavements. National Cooperative Highway Research Program,

Report No. 405, Transportation Research Board, National Research Council,

Washington, D.C.



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11. Saeed, A., Hall, J. and Barker, W, 2001, Performance-related Tests of aggregates

for Use in Unbound Pavement Layers. NCHRP Report # 453, National

Academy Press, Washington, D.C.

12. Williamson, G., Weyers, R. E., Mokarem, D., Lane, D., and Cady, P., Investigation

of Testing Methods to Determine Long-Term Durability of Wisconsin Aggregate

Resources Including Natural Materials, Industrial By-Products, and

Recycled/Reclaimed Materials. August, 2005.

13. Kandhal, P.S., and Parker, F., 1998, Aggregate Tests Related to Asphalt Concrete

Performance in Pavements. National Cooperative Highway Research Program,

Report No. 405, Transportation Research Board, National Research Council,

Washington, D.C.



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TABLES AND FIGURES

Figure 1 Pit and Quarry LocationsFigure 2 Vacuum Saturated Absorption vs. Vacuum Saturated Specific Gravity

Figure 3 Vacuum Saturated Absorption vs. L.A. Abrasion

Figure 4 Vacuum Saturated Absorption vs. Micro-Deval

Figure 5 Vacuum Saturated Absorption vs. Aggregate Crushing ValueFigure 6 L.A. Abrasion vs. Micro-Deval

Figure 7 L.A. Abrasion vs. Aggregate Crushing Value

Figure 8 Vacuum Saturated Absorption vs. Sodium Sulfate SoundnessFigure 9 Vacuum Saturated Absorption vs. Unconfined Freezing and Thawing

Figure 10 Aggregate Durability Testing Flowchart for Unbound Aggregate

Figure 11 Aggregate Durability Testing Flowchart for Bound Aggregate in PortlandCement Concrete

Table 1 Current WisDOT Testing Protocol

Table 2 Lightweight and Chert PercentagesTABLE 3 Current vs. Proposed Testing Protocol Comparison



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Quarry

Pit

FIGURE 1 - Pit and Quarry locations



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Vacuum Saturated Absorption vs. Vacuum Saturated Specific Gravity

R2= 0.7539

0

1

2

3

4

5

6

7

2.5 2.55 2.6 2.65 2.7 2.75 2.8 2.85 2.9 2.95 3

Vacuum Saturated Specific Gravity

VacuumS

aturatedAbs

orption

Igneous/Metamorphic Carbonate Linear (Carbonate)

FIGURE 2 - Vacuum Saturated Absorption vs. Vacuum Saturated Specific Gravity

Vacuum Saturated Absorption vs. L.A. Abrasion

R2= 0.572

0

1

2

3

4

5

6

7

0 10 20 30 40 50

L.A. Abrasion (% Loss)

VacuumS

aturatedAbsorption(%)

60

FIGURE 3 - Vacuum Saturated Absorption vs. L.A. Abrasion



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Vacuum Saturated Absorpt ion vs . Micro-Deval

R2= 0.8756

0

1

2

3

4

5

6

7

0 5 10 15 20 25 30 35 40 45

Micro-Deval (% Loss )

VacuumS

aturatedAbsorp

tion(%)

FIGURE 4 - Vacuum Saturated Absorption vs. Micro-Deval

Vacuum Saturated Absorption vs. Aggregate Crushing Value (VT)

R2= 0.547

0

1

2

3

4

5

6

7

10 12 14 16 18 20 22 24 26 28

Aggregate Crushing Value (% Los s)

VacuumS

aturatedAbsorpt

ion(%)

FIGURE 5 - Vacuum Saturated Absorption vs. Aggregate Crushing Value



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L.A. Abrasion vs. Mic ro-Deval

R2= 0.5623

0

10

20

30

40

50

60

0 5 10 15 20 25 30 35 40 45

Micro-Deval (% Loss)

L.A.

Abrasion(%L

oss

)

FIGURE 6 - L.A. Abrasion vs. Micro-Deval

L.A. Abrasion vs . Aggregate Crushing Value (VT)

R

2

= 0.794

0

10

20

30

40

50

60

10 12 14 16 18 20 22 24 26 28

Aggregate Crushing Value (% Loss)

L.A.

Abrasion(%L

oss)

FIGURE 7 - L.A. Abrasion vs. Aggregate Crushing Value



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FIGURE 8 - Vacuum Saturated Absorption vs. Sodium Sulfate Soundness

FIGURE 9 - Vacuum Saturated Absorption vs. Unconfined Freezing and ThawingFIGURE 9 - Vacuum Saturated Absorption vs. Unconfined Freezing and Thawing

Vacuum Saturated Absorption vs. Sodium Sulfate Soundness

R2= 0.3249

0

1

2

3

4

5

6

7

0% 5% 10% 15% 20% 25% 30% 35%

Sodium Sulfate So

VacuumS

aturatedAbsorp

tion(%)

undness (% Loss)

Vacuum Saturated Absorption vs.

0

1

2

3

4

5

6

7

0 2 4 6

Unconfined Freezing

VacuumS

aturatedAbsorption(%)

Unconfined Freezing and Thawing

R2= 0.1773

8 10 12 14 16

and Thawing (% Loss)


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FIGURE 10 - Aggregate Durability Testing Flowchart for Unbound Aggregate

Abs

L.A. Micro

% Lightweight >5%

No

Yes

Yes

REJECT

ACCEPT

A

Yes

Uncon

S

No

Samples Accepted

(Based on WisDOT

performance ratings)

Poor 2

Intermediate 4

Good - 5

Samples Rejected

(Based on WisDOT


Poor 5

Intermediate 2

Good - 0

Samples Accepted

(Based on WisDOT


Poor 0Intermediate 7

Good - 5

Unconfined F&T >15%

Yes

No



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illiamson, Weyers, Mokarem, and Lane 23

FIGURE 11 - Aggregate Durability Testing Flowchart for Bound Aggregate in P

Absorption > 2

L.A. Abrasion >Micro-Deval >2

% Lightweight >5%

Ye

No

Yes

Yes

REJECT

ACCEPT

ACCEPT

N

START

No

F&T C 666 > 40%

reduction in Freq.

excessive Agg. De

Yes

No

Samples A

(Based on Wi

performa

Poor 2

Intermedia

Good - 5

ccepted

sDOT

nce ratings)

te 4

Samples Rejected

(Based on WisDOT



Good - 0

Samples Accepted

(Based on WisDOT



Good - 5

F&T C 666 > 40%

reduction in Freq. or

excessive Agg. Det.

Yes

No

W


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TABLE 1 Current WisDOT Testing Protocol

Test Failure Criterion

Lightweight Pieces in Aggregate (AASHTO T 113) (7) > 5% Chert

Sodium Sulfate Soundness (AASHTO T 104) (7) > 12% Loss

Soundness of Aggregates by Freezing and Thawing (AASHTO T 103) (7) > 18% Loss

L.A. Abrasion (AASHTO T 96) (7) > 50% Loss

Current WisDOT Testing Protocol

TABLE 2 - Lightweight and Chert Percentages

Sample # % Lightweight (3/8") % Chert Sample # % Lightweight (3/8") % Chert

2 12.91 0.00 24 2.14 0.23

4 0.00 0.00 55 4.62 1.62

6 0.00 0.00 57 9.09 0.00

8 2.25 0.21 59 9.20 0.00

10 0.00 0.00 60 3.08 2.50

50 16.19 0.00 31 8.38 1.78

52 7.80 0.00 33 0.5 0.00

11 3.41 1.58 36 0.00 0.00

12 2.35 0.56 39 0.00 0.00

13 0.5 0.00 40 3.86 3.86

14 0.5 0.00 42 5.45 1.25

16 0.5 0.00 48 4.79 0.65

19 1.28 0.23 64 5.38 0.00

21 0.5 0.00 68 0.95 0.85

22 5.24 1.83 69 0.5 0.00

TABLE 3 Current vs. Proposed Testing Protocol Comparison

Aggregate

Quality Rating Rejected Accepted Rejected Accepted

Poor 3 4 5 2

Intermediate 1 12 2 11

Good 1 9 0 10

Current WisDOT Testing Protocol Proposed Protocol

Aggregate Strength

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