SVENSK STANDARD SS-EN 13286-47:2021

SS-EN 13286-47:2021SVENSK STANDARD

Språk: engelska / EnglishUtgåva: 3

Obundna och hydrauliskt bundna vägmaterial – Del 47: Provningsmetod för bestämning av CBR-värde, initialt bärighetsindex (IBI) och linjär svällning

Unbound and hydraulically bound mixtures – Part 47: Test method for the determination of California bearing ratio, immediate bearing index and linear swelling

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Fastställd: 2021-11-16ICS: 93.080.20

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Europastandarden EN 13286-47:2021 gäller som svensk standard. Detta dokument innehåller den officiella engelska versionen av EN 13286-47:2021.

Denna standard ersätter SS-EN 13286-47:2012, utgåva 2.

The European Standard EN 13286-47:2021 has the status of a Swedish Standard. This document contains the official version of EN 13286-47:2021.

This standard supersedes the SS-EN 13286-47:2012, edition 2.


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EUROPEAN STANDARD

NORME EUROPÉENNE

EUROPÄISCHE NORM

EN 13286-47

November 2021

ICS 93.080.20 Supersedes EN 13286-47:2012

English Version

Unbound and hydraulically bound mixtures - Part 47: Test method for the determination of California bearing ratio,

immediate bearing index and linear swelling

Mélanges traités et mélanges non traités aux liants hydrauliques - Partie 47: Méthode d'essai pour la

détermination de l'indice portant Californien (CBR), de l'indice de portance immédiate (IPI) et du gonflement

linéaire

Ungebundene und hydraulisch gebundene Gemische - Teil 47: Prüfverfahren zur Bestimmung des CBR-

Wertes (California bearing ratio), des direkten Tragindex (IBI) und des linearen Schwellwertes

This European Standard was approved by CEN on 5 July 2021. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION C O M I T É E U R O P É E N D E N O R M A L I S A T I O N E U R O P Ä I S C H E S K O M I T E E F Ü R N O R M U N G

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members.

Ref. No. EN 13286-47:2021 E

SS-EN 13286-47:2021 (E)


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Contents Page

European foreword ...................................................................................................................................................... 3

1 Scope .................................................................................................................................................................... 5

2 Normative references .................................................................................................................................... 5

3 Terms and definitions ................................................................................................................................... 5

4 Principle ............................................................................................................................................................. 6

5 Apparatus .......................................................................................................................................................... 6 5.1 Apparatus for specimen manufacture ..................................................................................................... 6 5.2 Additional apparatus for soaking procedure and measurement of swelling ........................... 6 5.3 Additional apparatus for determination of the California bearing ratio and

immediate bearing index ............................................................................................................................. 6

6 Test sample for the California bearing ratio and immediate bearing index tests .................. 7

7 Specimen manufacture for the California bearing ratio and immediate bearing index tests ...................................................................................................................................................................... 7

8 Curing for California bearing ratio test................................................................................................... 7 8.1 General................................................................................................................................................................ 7 8.2 Curing by prevention of evaporation ...................................................................................................... 8 8.3 Curing that permits full soaking ................................................................................................................ 8 8.4 Curing consisting of ‘prevention of evaporation’ followed by soaking ....................................... 9

9 Procedure for California bearing ratio and immediate bearing index determination ......... 9

10 Calculation and expression of results ................................................................................................... 10

11 Test report ....................................................................................................................................................... 11

Annex A (normative) Different Types of Force-Penetration Curves ....................................................... 12

A.1 Convex Upward Force-Penetration Curve ........................................................................................... 12

A.2 Force-Penetration Curve with Inflexion Point S at X < 7,5 mm .................................................... 13

A.3 Concave Upward Force-Penetration Curve with Inflexion Point S at X > 7,5 mm .................. 14

SS-EN 13286-47:2021 (E)


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European foreword

This document (EN 13286-47:2021) has been prepared by Technical Committee CEN/TC 227 “Road materials”, the secretariat of which is held by BSI.

This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 2022, and conflicting national standards shall be withdrawn at the latest by May 2022.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN 13286-47:2012.

In comparison with the previous edition, the following technical modifications have been made:

— editorial changes;

— a revised Clause 10 that provides more information for the possible force-penetration curves and where necessary their correction;

— a revised Annex A reflecting the revised Clause 10. The Annex A is normative.

This document is one of a series of standards as listed below:

— EN 13286-1, Unbound and hydraulically bound mixtures — Part 1: Test methods for laboratory reference density and water content — Introduction, general requirements and sampling

— EN 13286-2, Unbound and hydraulically bound mixtures — Part 2: Test methods for laboratory reference density and water content — Proctor compaction

— EN 13286-3, Unbound and hydraulically bound mixtures — Part 3: Test methods for laboratory reference density and water content — Vibrocompression with controlled parameters

— EN 13286-4, Unbound and hydraulically bound mixtures — Part 4: Test methods for laboratory reference density and water content — Vibrating hammer

— EN 13286-5, Unbound and hydraulically bound mixtures — Part 5: Test methods for laboratory reference density and water content — Vibrating table

— EN 13286-7, Unbound and hydraulically bound mixtures — Part 7: Cyclic load triaxial test for unbound mixtures

— EN 13286-40, Unbound and hydraulically bound mixtures — Part 40: Test method for the determination of the direct tensile strength of hydraulically bound mixtures

— EN 13286-41, Unbound and hydraulically bound mixtures — Part 41: Test method for the determination of the compressive strength of hydraulically bound mixtures

— EN 13286-42, Unbound and hydraulically bound mixtures — Part 42: Test method for the determination of the indirect tensile strength of hydraulically bound mixtures

SS-EN 13286-47:2021 (E)


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— EN 13286-43, Unbound and hydraulically bound mixtures — Part 43: Test method for the determination of the modulus of elasticity of hydraulically bound mixtures

— EN 13286-44, Unbound and hydraulically bound mixtures — Part 44: Test method for the determination of the alpha coefficient of vitrified blast furnace slag

— EN 13286-45, Unbound and hydraulically bound mixtures — Part 45: Test method for the determination of the workability period of hydraulically bound mixtures

— EN 13286-46, Unbound and hydraulically bound mixtures — Part 46: Test method for the determination of the moisture condition value

— EN 13286-47, Unbound and hydraulically bound mixtures — Part 47: Test method for the determination of California bearing ratio, immediate bearing index and linear swelling

— EN 13286-48, Unbound and hydraulically bound mixtures — Part 48: Test method for the determination of degree of pulverisation

— EN 13286-49, Unbound and hydraulically bound mixtures — Part 49: Accelerated swelling test for soil treated by lime and/or hydraulic binder

— EN 13286-50, Unbound and hydraulically bound mixtures — Part 50: Method for the manufacture of test specimens of hydraulically bound mixtures using Proctor equipment or vibrating table compaction

— EN 13286-51, Unbound and hydraulically bound mixtures — Part 51: Method for the manufacture of test specimens of hydraulically bound mixtures using vibrating hammer compaction

— EN 13286-52, Unbound and hydraulically bound mixtures — Part 52: Method for the manufacture of test specimens of hydraulically bound mixtures using vibro compression

— EN 13286-53, Unbound and hydraulically bound mixtures — Part 53: Methods for the manufacture of test specimens of hydraulically bound mixtures using axial compression

— CEN/TS 13286-54, Unbound and hydraulically bound mixtures — Part 54: Test method for the determination of frost susceptibility — Resistance to freezing and thawing of hydraulically bound mixtures

Any feedback and questions on this document should be directed to the users’ national standards body. A complete listing of these bodies can be found on the CEN website.

According to the CEN-CENELEC Internal Regulations, the national standards organisations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

SS-EN 13286-47:2021 (E)


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1 Scope

This document specifies the test methods for the laboratory determination of the California bearing ratio and immediate bearing index.

The tests are appropriate to that part of the mixture up to a maximum particle size of 22,4 mm.

When immersion in water is specified as part of the curing of the specimen, this document also includes the determination of vertical swelling of the specimen before the determination of the California bearing ratio.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

EN 1097-5, Tests for mechanical and physical properties of aggregates - Part 5: Determination of the water content by drying in a ventilated oven

EN 13286-2, Unbound and hydraulically bound mixtures - Part 2: Test methods for laboratory reference density and water content - Proctor compaction

3 Terms and definitions

For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http://www.electropedia.org/

— ISO Online browsing platform: available at https://www.iso.org/obp

3.1 California bearing ratio ratio used to characterise the bearing capacity of a mixture, determined immediately after compaction, or after a period of curing

3.2 immediate bearing index immediate California bearing ratio test without surcharge

3.3 Proctor compactive effort compactive effort used in the Proctor test described in EN 13286-2

3.4 modified Proctor compactive effort compactive effort used in the modified Proctor test described in EN 13286-2

3.5 curing period of time and storage condition between manufacture and testing of the specimen for the California bearing ratio

SS-EN 13286-47:2021 (E)


http://www.electropedia.org/

https://www.iso.org/obp

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4 Principle

The relationship between force and penetration is determined when a cylindrical piston of a standard cross-sectional area is made to penetrate a specimen of a mixture, contained within a mould, at a given rate.

The California bearing ratio or immediate bearing index is calculated by expressing the force on the piston for a given penetration as a percentage of a reference force.

5 Apparatus

5.1 Apparatus for specimen manufacture

5.1.1 Proctor mould B with appropriate spacer disc, if required, conforming to EN 13286-2.

5.1.2 Rammer A or B, conforming to EN 13286-2.

5.1.3 Balance accurate to ± 0,1 % of mass weighed and capable of weighing up to 30 kg.

5.1.4 Apparatus conforming to EN 1097-5 for water content determination.

5.1.5 Miscellaneous apparatus including coarse filter papers, a steel straightedge, scrapers, etc.

5.2 Additional apparatus for soaking procedure and measurement of swelling

5.2.1 Base plate uniformly perforated for minimum 1 % of its surface.

5.2.2 Perforated top plate in aluminium alloy with adjustable stem to provide the seating for the stem of a dial gauge.

5.2.3 Unperforated top plate in aluminium alloy with a thickness (10 ± 1) mm with adjustable stem to provide the seating for the stem of a dial gauge.

5.2.4 Device for measuring the vertical expansion of the specimen for the California bearing ratio accurate to 0,05 mm.

5.2.5 Soaking tank, large enough to allow the Proctor mould B to be submerged, preferably supported on an open mesh platform.

5.2.6 Annular surcharge rings, each having a mass known to ± 100 g, an internal diameter of (53 ± 1) mm and an external diameter equal to the diameter of the mould minus 5 mm.

Alternatively half-annular segments may be used.

5.3 Additional apparatus for determination of the California bearing ratio and immediate bearing index

5.3.1 Cylindrical penetration piston with a diameter of (50 ± 0,5) mm, the lower end of which shall be of hardened steel.

5.3.2 Loading machine with a capacity of at least 50 kN capable of applying the test force through the piston at a penetration rate of (1,27 ± 0,20) mm/min.

The machine shall be equipped with a load-indicating device that can be read to 5 N or less.

SS-EN 13286-47:2021 (E)


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6 Test sample for the California bearing ratio and immediate bearing index tests

After sieving on a 22,4 mm sieve, approximately 7,5 kg of mixture shall be used for one test and water content determination. The quantity shall be weighed accurately so that the actual quantity used for the test sample can be determined after compaction by difference for checking purposes. NOTE It is possible that preliminary trials are necessary to ascertain the required quantity more closely.

The determination of the immediate bearing index shall be carried out no later than 90 min after mixing for all hydraulically bound mixtures but no sooner than 60 min where lime is used.

7 Specimen manufacture for the California bearing ratio and immediate bearing index tests

7.1 Clamp the mould, with extension collar attached, to the base plate. Insert the spacer disc over the base plate and place an anti-sticking medium such as coarse filter paper on top of the spacer disc. The California bearing ratio assembly shall be placed on a solid substrate e.g. concrete or plinth, prior to specimen manufacture. Compact the mixture into the mould using either Proctor or modified Proctor compactive effort in accordance with EN 13286-2.

NOTE It is normal but not universal practice to use a mould that requires the use of a spacer disc.

7.2 After compaction, remove the extension collar and carefully trim the mixture flush with the top of the mould with the scraper, checking with the steel straightedge. Patch with smaller size material any holes that may have developed in the surface during trimming.

7.3 Remove the baseplate and spacer disc (where used), weigh, and record the mass of the mould and mixture to the nearest 5 g.

NOTE In the case of mixtures lacking cohesion, it would be better to weigh the mould and mixture with the baseplate and spacer disc attached to avoid loss of mixture.

7.4 For immediate California bearing ratio and immediate bearing index tests, proceed to Clause 9, if not, the specimen shall be cured using one of the procedures described in Clause 8.

7.5 The material surplus to that required for the test specimen shall be used to determine, in accordance with EN 1097-5, the water content of the test portion.

8 Curing for California bearing ratio test

8.1 General

A curing period, which may be required between specimen manufacture and testing, shall consist of the storage of the specimens for a specified period of time in one of the following states:

a) a condition that prevents evaporation resulting in a loss of mass of more than 2 %;

b) a condition that permits full soaking of the specimens (immersion);

c) ‘prevention of evaporation’ [as in a)] followed by full soaking.

In each case, the type of curing, the average temperature and duration of storage shall be recorded and stated.

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8.2 Curing by prevention of evaporation

Curing by prevention of water loss by evaporation shall be carried out by one of the following methods:

a) storage in a climatic cabinet or room with a relative humidity of at least 98 %;

b) coating the ends of the specimen with wax;

c) placing the end caps on the mould and sealing them with petroleum jelly, silicon or tape;

d) or other appropriate methods.

Specimens shall be stored at (20 ± 2) °C or other specified temperature.

8.3 Curing that permits full soaking

8.3.1 Place a disc of coarse filter paper on the perforated baseplate, invert the mould containing the compacted specimen, and clamp the baseplate to the mould so that the specimen is in contact with the filter paper.

NOTE 1 The top of the specimen is now at the underside in contact with the filter paper.

NOTE 2 Where the specimen has been made in a mould that does not require a spacer disc, the collar is screwed to what is now the top of the mould and the joint sealed.

8.3.2 Place a filter paper on top of the specimen followed by the perforated top plate and the fitting of the requisite number of annular surcharge discs around the stem on the perforated plate. The use of surcharge will depend on circumstances and shall be specified accordingly.

NOTE A surcharge disc of mass 2 kg simulates the effect of 70 mm of superimposed construction.

8.3.3 Place the California bearing ratio assembly and specimen in an immersion tank filled with water, at a temperature of (20 ± 2) °C, to a level that allows free access of water to the top and bottom of the specimen.

8.3.4 Mount and secure the device for measuring vertical expansion of the specimen on the mould.

8.3.5 Take initial readings for swell and allow the specimen to soak for a minimum of 96 h. Maintain a constant water level during this period.

8.3.6 If required, measure expansion to 0,05 mm at suitable intervals of time depending on the rate of vertical swell and plot a graph of expansion against elapsed time or square-root of time.

NOTE Flattening of the curve indicates when swelling is substantially complete.

8.3.7 At the end of the soaking period, take final measurements and calculate the final swell as a percentage of the initial height of the specimen.

8.3.8 On completion of soaking, remove the expansion measuring device from the California bearing ratio assembly and specimen, remove the California bearing ratio assembly and specimen from the tank, and allow the specimen to drain for (15 ± 1) min.

8.3.9 Remove the surcharge discs (if used) and perforated top plate and baseplate, weigh, and record the mass of the mould and specimen.

NOTE See Note to 7.3.

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8.4 Curing consisting of ‘prevention of evaporation’ followed by soaking

Curing consisting of ‘prevention of evaporation’ followed by soaking shall be carried out as described in 8.2 and 8.3 except that after storage to prevent loss of water, the wax or end caps shall be removed from the specimen as appropriate prior to storage in a soaked condition.

9 Procedure for California bearing ratio and immediate bearing index determination

9.1 This method describes the procedure for determining the California bearing ratio or immediate bearing index of the specimen whether or not it has been cured as described in Clause 8.

9.2 Attach the baseplate to the mould such that the baseplate is in contact with the original top of the specimen and the bottom face is exposed and can be tested, and place the mould on the lower plate of the testing machine.

9.3 For immediate bearing index determination or California bearing ratio determination after a period of curing without surcharge, proceed to 9.5.

9.4 For California bearing ratio determination with surcharge, place the requisite number of surcharge weights on the specimen. If the specimen has been soaked previously, the surcharge shall be equal to that used during the soaking period (see 8.3.2). To prevent upheaval of the mixture into the hole of the weights, place just one surcharge disc on the mixture prior to seating the penetration piston, after which, place the remainder of the surcharge weights.

9.5 Depending on the expected California bearing ratio/immediate bearing index and if necessary, apply a seating force to the piston as follows:

— Ratio/index up to 5 %: 10 N,

— Ratio/index greater than 5 %: 40 N.

Record the reading of the force measuring device as the initial zero reading.

9.6 Secure the penetration dial gauge or similar device in position and record the initial zero reading.

9.7 Apply the load on the penetration piston so that the rate of penetration is approximately 1,27 mm/min. Record the load readings at penetration increments of 0,5 mm up to a total penetration not exceeding 10 mm.

9.8 After the test has been completed, remove the specimen from the mould. Determine the average water content of the specimen. Each water content sample shall weigh not less than 100 g for fine grained mixtures and 500 g for coarse grained mixture and shall be determined in accordance with EN 1097-5.

NOTE If the sample has been soaked, the water content after soaking will generally exceed the initial water content. Because of the possibility of water content gradients in the soaked specimen, it is also possible that the value changes along the length of the specimen.

SS-EN 13286-47:2021 (E)


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10 Calculation and expression of results

10.1 Plot each value of force as ordinate against the corresponding penetration as abscissa and draw a smooth curve through the points.

10.2 Different types of force-penetration curves are possible which may or may not require correction in order to establish the California Bearing Ratio/immediate bearing index.

10.3 The normal type of curve is convex upwards and needs no correction (Annex A, Figure A.1). From the test-curve read off the forces in kN corresponding to the 2,5 mm and 5 mm penetration. Express these as a percentage of the reference forces at these penetrations, 13,2 kN and 20 kN respectively. Take the higher percentage as the California bearing ratio/immediate bearing index value.

10.4 When the initial part of the curve is concave upwards, which may be due to surface irregularities, a correction shall be made by drawing a tangent to the curve at the point of the greatest slope i.e. the point of inflexion, S (Annex A, Figures A.2 and A.3).

10.4.1 Where S < 7,5mm (Annex A, Figure A.2), take the intersection of this tangent and the penetration axis as the new origin, Q. The corrected force/penetration curve to be used in the calculations shall be this tangent from where it cuts the penetration abscissa to its point of contact with the curve and hence the curve itself. Thus the corrected curve shall be represented by QST, with its origin at Q, from which a new penetration scale can be marked.

10.4.2 Where penetrations greater than 7,5 mm are required to obtain a corrected value for 5 mm penetration, i.e. S > 7,5 mm, then the correction should be made from 7,5 mm (Annex A, Figure A3). This correction shall apply even if a point of inflexion is not achieved before 10 mm penetration.

10.5 California bearing ratio/immediate bearing index shall be recorded as in Table 1.

Table 1 — Reported California bearing ratio/immediate bearing index value

California bearing ratio/immediate bearing index range Nearest

%

0 to 9 0,5

10 to 29 1

> 29 5

NOTE If the operator plots the force penetration curve as the test is being carried out, the test can be terminated when the indicated California bearing ratio/immediate bearing index falls below its maximum value. Thus if the California bearing ratio / immediate bearing index at 2,5 mm was seen to be 6 % but by 3,5 mm penetration it was seen to have fallen below this value, the test could be stopped and the result reported as follows:

— 2,5 mm penetration 6 %;

— 5,0 mm penetration < 6 %.

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11 Test report

The report shall contain the following information:

a) sample identification;

b) California bearing ratio/immediate bearing index value(s) obtained and in the case of the California bearing ratio with surcharge, the mass of the surcharge used during the test;

c) compactive effort;

d) water content and dry density of the specimen at preparation;

e) water content of the specimen at the time of test;

f) age of specimen at test and where applicable the duration of curing time and or soaking time;

g) conditions of curing and storage (temperature, time description) if applicable;

h) amount of expansion during soaking and the surcharge used during soaking if applicable;

i) time to maximum expansion if measured;

j) Type of force-penetration curve;

k) California bearing ratio/immediate bearing index was determined in accordance with this document.

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Annex A (normative)

Different Types of Force-Penetration Curves

A.1 Convex Upward Force-Penetration Curve

Key X Penetration in mm Y Force in kN

Figure A.1 —Convex Upward Force-Penetration Curve (no correction necessary)

Table A.1 — Determination of the CBR/Immediate Bearing Index value in Figure A.1

Penetration Force Reference Force CBR/Immediate

Bearing Index Value F Fref

mm kN kN %

2,5 3,0 13,2 23

5,0 4,8 20 24

The CBR/Immediate Bearing Index value is 24 %.

SS-EN 13286-47:2021 (E)


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A.2 Force-Penetration Curve with Inflexion Point S at X < 7,5 mm

Key X Penetration in mm Y Force in kN Q New origin of coordinates S Inflexion point T End of curve QST Corrected Force-Penetration-curve

Figure A.2 — Force-Penetration Curve with Inflexion Point S at X < 7,5 mm


Corrected Penetration Depth

Corrected Force Reference Force CBR/Immediate Bearing Index value F Fref

mm kN kN %

3,7 2,4 13,2 18

6,2 4,6 20 23


SS-EN 13286-47:2021 (E)


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A.3 Concave Upward Force-Penetration Curve with Inflexion Point S at X > 7,5 mm

In the case that the new origin of coordinates is higher than 2,5 mm (Figure A.3), the computation of the CBR or the Immediate Bearing Index value is determined as follows:

— the penetration depth at 5 mm corresponds to the corrected value for the 2,5 mm penetration depth

— the penetration depth at 7,5 mm corresponds to the corrected value for the 5,0 mm penetration depth

Key X Penetration in mm Y Force in kN Q New origin of coordinates S Inflexion point of curve T End of curve

Figure A.3 — Force-penetration curve with inflexion point S at X > 7,5 mm


Corrected Penetration Depth

Corrected Force Reference Force CBR/Immediate Bearing Index value F Fref

mm kN kN %

5,0 1,05 13,2 8,0

7,5 4,8 20 24


SS-EN 13286-47:2021 (E)


Anteckningar/Notes


SVENSK STANDARD SS-EN 13286-47:2021

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