prEN 15732

Lightweight fill and thermal insulation products for civil engineering applications (CEA) - Expanded clay lightweight aggregate products (LWA)

This document specifies the assessment of characteristics for loose-fill expanded clay lightweight aggregate products (hereafter as: expanded clay LWA) intended to be used for application in civil engineering works.
This document covers the use of expanded clay LWA as:
-   lightweight fill and insulation materials in embankments for roads, railways and other trafficked areas;
-   lightweight backfill for structures.
This document specifies procedures for assessment and verification of constancy of performance (AVCP) of characteristics of the expanded clay LWA.
This document does not cover the expanded clay LWA:
-   which are intended to be used as thermal insulation in- and under buildings (already covered in EN 14063-1:2004).

Leichte Schütt- und Wärmedämmstoffe für bautechnische Anwendungen (CEA) - Produkte aus Blähton-Leichtzuschlagstoffen (LWA)

Dieses Dokument legt die Eigenschaften von Schüttdämmstoffen aus Blähton Leichtzuschlagstoffen (Blähton LWA) für bautechnische Zwecke fest. Ausgenommen sind Anwendungen als Wärmedämmung in und unter Gebäuden, die in EN 14063-1 erfasst werden. In dem vorliegenden Dokument wird die Anwendung von Blähton Leichtzuschlagstoffen als leichte Schütt  und Dämmstoffe an Straßendämmen, Schienenwegen und anderen befahrbaren Bereichen sowie ihre Anwendung als leichte Hinterfüllung für Bauwerke beschrieben.
Darüber hinaus beschreibt dieses Dokument die Produkteigenschaften und enthält Verfahren zur Prüfung, Bewertung und Überprüfung der Leistungsbeständigkeit (AVCP), Kennzeichnung und Etikettierung.
Dieses Dokument legt keine Anforderungsstufen für eine bestimmte Eigenschaft fest, die ein Produkt erreichen muss, um für einen bestimmten Anwendungszweck gebrauchstauglich zu sein.

Matériaux de remplissage légers et produits isolants thermiques pour les applications du génie civil - Produits à base de granulats légers d’argile expansée

Le présent document spécifie les caractéristiques concernant les produits en vrac à base de granulats légers d’argile expansée pour les applications du génie civil, à l’exclusion de leur utilisation comme isolant thermique dans et sous les bâtiments qui est traitée par l’EN 14063-1. Le présent document couvre l’utilisation des granulats légers d’argile expansée comme matériau de remplissage léger et matériau isolant dans les talus pour les chaussées, les voies ferrées et d’autres zones de circulation, ainsi que comme remblai léger pour les structures.
Le présent document décrit également les caractéristiques des produits et inclut les modes opératoires d’essai, d’évaluation et de vérification de la constance des performances (EVCP), de marquage et d’étiquetage.
Le présent document ne spécifie pas le niveau requis d’une propriété donnée devant être atteint par un produit pour en démontrer l’aptitude à l’emploi dans une application particulière.

Toplotnoizolacijski in lahki polnilni proizvodi za inženirske objekte - Proizvodi iz ekspandiranega glinenega agregatnega proizvoda (LWA)

General Information

• Status: Withdrawn
• Publication Date: 22-Feb-2021
• Withdrawal Date: 23-May-2021
• ICS: 91.100.60 - Thermal and sound insulating materials
• Technical Committee: CEN/TC 88 - Thermal insulating materials and products
• Drafting Committee: CEN/TC 88/WG 20 - Project development of WI 00088165.
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 17-Jun-2020
• Due Date: 28-Nov-2020
• Completion Date: 17-Jun-2020
• Directive: 305/2011 - Regulation (eu) No 305/2011 of the European Parliament and of the Council of 9 march 2011 laying down harmonised conditions for the marketing of construction products and repealing council directive 89/106/eec
• Directive: 89/106/EEC - Construction products
• Mandate: M/103 - Mandate to CEN/CENELEC concerning the execution of standardization work for harmonized standards on thermal insulating products
• Mandate: M/138 - Addendum to Mandate M/103 on Thermal Insulation Products
• Ref Project: oSIST prEN 15732:2008 - Light weight fill and thermal insulation products for civil engineering applications (CEA) - Expanded clay lightweight aggregate products (LWA)

Relations

• Revises: EN 15732:2012 - Light weight fill and thermal insulation products for civil engineering applications (CEA) - Expanded clay lightweight aggregate products (LWA)
• Effective Date: 21-Mar-2018

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 15732:2008
01-februar-2008

Toplotnoizolacijski in lahki polnilni proizvodi za inženirske objekte - Proizvodi iz

ekspandiranega glinenega agregatnega proizvoda (LWA)

Light weight fill and thermal insulation products for civil engineering applications (CEA) -

Expanded clay lightweight aggregate products (LWA)
Leichte Schütt- und Wärmedämmstoffe für bautechnische Anwendungen (CEA) -
Produkte aus Blähton-Leichtzuschlagstoffen (LWA)
Ta slovenski standard je istoveten z: prEN 15732
ICS:
91.100.60
oSIST prEN 15732:2008 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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EUROPEAN STANDARD
DRAFT
prEN 15732
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2007
ICS 91.100.60
English Version
Light weight fill and thermal insulation products for civil
engineering applications (CEA) - Expanded clay lightweight
aggregate products (LWA)
Leichte Schütt- und Wärmedämmstoffe für bautechnische
Anwendungen (CEA) - Produkte aus Blähton-
Leichtzuschlagstoffen (LWA)

This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 88.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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 Management Centre has the

same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,

France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,

Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to

provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and

shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels

© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 15732:2007: E

worldwide for CEN national Members.
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prEN 15732:2007 (E)
Contents Page

Foreword..............................................................................................................................................................3

1 Scope ......................................................................................................................................................3

2 Normative references ............................................................................................................................3

3 Terms, definitions, symbols, units and abbreviated terms...............................................................4

4 Requirements.........................................................................................................................................5

5 Test methods..........................................................................................................................................8

6 Designation code.................................................................................................................................10

7 Evaluation of conformity.....................................................................................................................10

8 Marking and labelling ..........................................................................................................................10

Annex A (normative) Test for mechanical and physical properties of expanded clay LWA -

Triaxial Test for determination of shear strength properties..........................................................11

Foreword............................................................................................................................................................11

Annex B (normative) Test for mechanical and physical properties of expanded clay LWA —

Determination of the resistance to cyclic compressive loading ....................................................25

Annex C (normative) Test for mechanical and physical properties of expanded clay LWA —

Determination of the compressive creep ..........................................................................................31

Annex D (normative) Factory production control ........................................................................................36

Annex E (informative) Tabulated λλ -values of expanded clay LWA in lightweight fill

10,dry

applications ..........................................................................................................................................37

Annex ZA (informative) Clauses of this European Standard addressing the provisions of the EU

Construction Products Directive........................................................................................................38

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prEN 15732:2007 (E)
Foreword

This document (prEN 15732:2007) has been prepared by Technical Committee CEN/TC 88 “Thermal

insulating materials and products”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.

This document has been prepared under a mandate given to CEN by the European Commission and the

European Free Trade Association, and supports essential requirements of EU Directive(s). This document has

been progressed to CEN Enquiry even though a confirmation from the Commission that it can be considered as a

candidate harmonized standard is outstanding. An answer is being expected before the formal vote procedure. An

amendment to the answer to mandate M/103 is finalized.

For relationship with EC Directive(s), see informative Annex ZA which is an integral part of this document.

1 Scope

This standard describes the product characteristics and includes procedures for testing, marking and labelling.

This European Standard specifies the requirements for loose-fill expanded clay lightweight aggregate

(expanded clay LWA) products for Civil Engineering Applications excluding the use as thermal insulation in

and under buildings which are covered by European Standard EN 14063-1. The standard covers the use of

expanded clay LWA as lightweight fill and insulation materials in embankments for roads, railways and other

trafficked areas and as lightweight backfill for structures.

This standard does not specify the required level of a given property to be achieved by a product to

demonstrate fitness for purpose in a particular application. The levels required for a given application are to be

found in regulations or non-conflicting standards.
2 Normative references

The following referenced documents are indispensable for the application 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 932-1, Test for general properties of aggregates - Part 1: Methods for sampling

EN 932-2, Test for general properties of aggregates - Part 2: Methods for reducing laboratory samples

EN 933-1, Test for geometrical properties of aggregates - Part 1: Determination of particle size distribution -

Sieving method

EN 1097-3, Test for mechanical and physical properties of aggregates - Part 3: Determination of loose bulk

density and voids

EN 1097-5, Test for mechanical and physical properties of aggregates - Part 5: Determination of water content

by drying in a ventilated oven

EN 1097-6, Test for mechanical and physical properties of aggregates - Part 6: Determination of particle

density and water absorption

EN ISO 10456, Thermal insulation building materials and products – Determination of declared and design

values (ISO 10456:1999)
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prEN 15732:2007 (E)

EN 12524, Building materials and products – Hygrothermal properties – Tabulated design values

EN 13055-1, Lightweight aggregates – Part 1: Lightweight aggregates for concrete, mortar and grout

EN 13055-2, Lightweight aggregates – Part 2: Lightweight aggregates for bituminous mixtures and surface

treatments and for unbound and bound applications.
EN 13172, Thermal Insulation products - Evaluation of conformity

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 13501-1, Fire classification of construction products and building elements – Part 1: Classification using

test data from reaction to fire test

EN 13820, Thermal insulation materials for building applications - Determination of organic content

EN 14063-1, Thermal insulation materials and products – In-situ formed expanded clay lightweight aggregate

products (LWA) – Part 1: Specification for the loose-fill products before installation

prEN ISO 9229, Thermal insulation – Definitions of terms (ISO/DIS 9229:2005)
3 Terms, definitions, symbols, units and abbreviated terms
3.1 Terms and definitions

For the purposes of this document, the following terms and definitions apply. Other terms used for insulation

products are given in prEN ISO 9229.
3.1.1
expanded clay lightweight aggregate

Insulation material or product composed of lightweight granular material having a cellular structure formed by

expanding clay minerals by heat.
3.1.2
compressibility

Deformation at a certain load of a vibrated specimen, given as a load-deformation curve

3.1.3
compressive strength, CS(10)
The load where the deformation of a vibrated specimen is 10%
3.1.4
stiffness modulus

The stiffness modulus is given as the tangent to the load-deformation curve and shall be related to the level of

deformation.
3.1.5
compressive creep (CC)
Compressive creep is the deformation at a constant load in a specified time.
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prEN 15732:2007 (E)
3.1.6
compaction

Mechanical compression (e.g. by vibrator) of the installed insulation layer, expressed as a percentage of the

initial untreated layer thickness.
3.1.7
level

Given value, which is the upper or lower limit of a requirement. The level is given by the declared value of the

characteristic concerned.
3.1.8
class

Combination of two levels of the same property, between which the performance shall fall, where the levels

are given by the declared value of the characteristic concerned.
3.2 Symbols, units and abbreviated terms
Symbols and units used in this standard:
LD is the symbol of the declared level for loose bulk density
PS is the symbol of the declared level for aggregate size (mm)

CS(10) is the symbol of the declared level for compressive strength at 10 % deformation

CC is the symbol of the declared level for compressive creep
Abbreviated terms used in this standard:
LWA is Lightweight Aggregate
ITT is Initial Type Test
CEA is Civil Engineering Applications
4 Requirements
4.1 General

Product properties shall be assessed in accordance with Clause 5. To conform with this standard, products

shall meet the requirements of 4.2 and the requirements of 4.3 as appropriate.

Sampling of expanded clay LWA shall be performed according to EN 932-1 and splitting of samples according

to EN 932-2.

One test result on a product property is the average of the measured values on the number of test specimens

given in Table 1.
4.2 For all applications
4.2.1 Loose bulk density

Loose bulk density shall be declared and determined in accordance with EN 1097-3. The dry loose bulk

3 3

density shall be declared by the manufacturer with steps of 5 kg/m up to a density of 400 kg/m and thereafter

with steps of 10 kg/m . It shall be in the range of ±15% of the manufacturers declared value with a maximum of

3 3
± 100 kg /m .The value shall be expressed in kg/m .

NOTE The value of the density used for design purposes will be influenced by compaction and water content

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prEN 15732:2007 (E)
4.2.2 Particle size distribution
4.2.2.1 General

Particle size distribution shall be measured in accordance with EN 933-1, without washing, and shall be

declared in % by mass.
4.2.2.2 Aggregate size

The pair of sieve sizes between which the main proportion of the particles lies shall designate the size and

any undersize or oversize shall comply with clauses 4.2.2.3 and 4.2.2.4.
The sieve sizes in mm shall be selected from the specifications in EN 13055-2.

NOTE Normally the aggregate size for expanded clay LWA products will be in the range 0 mm - 32 mm.

4.2.2.3 Undersize
The content of undersize material shall not exceed 15% by mass.
4.2.2.4 Oversize
The content of oversize material shall not exceed 10% by mass.
4.2.3 Reaction to fire

Reaction to fire classification (Euroclasses) shall be determined in accordance with EN 13501-1.

NOTE Expanded clay LWA described in clause 3.1.1 of the standard is classified, without testing, as a class A1

product in accordance with Commission Decision 96/603/EC as amended by decision 2000/605/EC as it is demonstrated

that the product has an organic content less than 1 %, determined by EN 13820.
4.2.4 Durability characteristics
4.2.4.1 General

The appropriate durability characteristics have been considered and are covered in 4.2.4.2 to 4.2.4.6.

Note: The product is a clay mineral product burnt to clinkers in a stable structure.

4.2.4.2 Durability of reaction to fire against ageing/degradation
The reaction to fire performance of expanded clay LWA does not change with time.
4.2.4.3 Durability of thermal resistance against ageing/degradation
The thermal conductivity (4.3.3) of the product does not change with time.
4.2.4.4 Durability of compressive strength against ageing/degradation
The compressive strength of expanded clay does not change with time.
4.2.4.5 Durability of resistance to dynamic loads against ageing/degradation
The resistance to dynamic loads does not change with time.
4.2.4.6 Durability against chemicals and biological attack

The expanded clay LWA is a ceramic material and is durable against chemicals and biological attack.

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prEN 15732:2007 (E)
4.3 For specific applications
4.3.1 General

If there is no requirement for a property, described in 4.3.2 – 4.3.16, for a product in use, then the property

need not to be determined and declared by the manufacturer.
4.3.2 Thermal resistance and thermal conductivity

The thermal conductivity and thermal resistance shall be determined in accordance with EN 14063-1.

For light weight fill applications without thermal insulation requirements it is permitted to declare tabulated

thermal values in accordance with annex E.
4.3.3 Specific heat capacity

A typical value of 1000 J/kgK can be used for the specific heat capacity of expanded clay LWA, in accordance

with EN 12524.
4.3.4 Particle density

The particle density of the grains shall be determined in accordance with EN 1097-6, Annex C. It shall be in

the range of ± 15% with a maximum of ± 150 kg/m of the declared value.
4.3.5 Water content
The water content shall be determined in accordance with EN 1097-5.
4.3.6 Water absorption

The water absorption shall be determined in accordance with EN 1097-6, Annex C. Water absorption test

should be performed also with an immersion time of 28 days.
4.3.7 Compressibility and compressive strength

The compressibility, in terms of load-deformation curve, stiffness modulus, and the compressive strength

CS(10) shall be determined in accordance with EN 13055-2, Annex A. The stiffness modulus shall be given as

the tangent to the load-deformation curve and related to the level of deformation.

NOTE The compressive strength at 10% deformation is not a design value, it is used as a reference value for

material characterisation only. For characterisation of material properties the stiffness modulus and the load at a

deformation level at maximum 2% is more relevant.
4.3.8 Compressive creep

The compressive creep, in terms of deformation in % of the height of a vibrated sample, shall be determined

in accordance with Annex C. The load shall be applied in load steps corresponding to stress levels of 50kPa

from 50 kPa and upwards.
4.3.9 Shear strength – static loading

The shear strength properties shall be determined in accordance with Annex A. The method using the

pressure cell, annex A6, shall be used as reference test method.
4.3.10 Cyclic compression

The cyclic compression shall be determined in accordance with Annex B. The cyclic load shall be applied in

load steps corresponding to stress levels of 50kPa from 50 kPa and upwards. The results shall be given as

deformation in % related to the stress level.
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prEN 15732:2007 (E)
4.3.11 Shear strength – cyclic loading

The resilient modulus (elastic stiffness) and resistance to permanent deformations shall be determined by

cyclic triaxial tests. Cyclic triaxial testing shall be performed in accordance with EN 13286-7. The multistage

loading procedure (low stress level) shall be followed.

NOTE The development of permanent deformations is highly dependent on the stress history. This should be taken

into consideration when the results from the test are used.
4.3.12 Water permeability

The property is not measured because the open structure of the final product itself offers no substantial

resistance to the free movement of water.

NOTE Based on experience; the typical graded expanded clay LWA has a measured permeability greater than 10

m/s.
4.3.13 Water vapour transmission

The property is not measured because the open structure of the final product itself offers no substantial

resistance to the free movement of water vapour.

Note According to EN 12524 a typical water vapour diffusion resistance factor is 2.

4.3.14 Chemical content

The chemical content of the expanded clay LWA shall be determined in accordance with EN 13055-2.

4.3.15 Freezing and thawing resistance

The freezing and thawing resistance of expanded clay LWA shall be determined in accordance with EN

13055-2 Annex B.
4.3.16 Release of dangerous substances
NOTE See Annex ZA.1.
4.4 Other requirements
4.4.1 Crushing resistance

The crushing resistance shall be measured in accordance with EN 13055-1 Annex A. Each vibration time shall

2 2

be 30 seconds and the result shall be expressed in N/mm , and in levels with steps of 0,05 N/mm up to 1,0

2 2
N/mm and thereafter with steps of 0,1 N/mm .

NOTE The crushing resistance is not a design value, it is used for quality documentation and factory production

control only.
5 Test methods
5.1 Sampling
Sampling shall be carried out according to the procedures given in EN 932-1.
5.2 Conditioning

If not otherwise prescribed in the test method, the test specimens shall be dried to constant mass at (110 +/-

5) ºC according to EN 1097-5.
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prEN 15732:2007 (E)
5.3 Testing
5.3.1 General

Table 1 gives the dimensions of the test specimens, the minimum number of measurements required to get one test

result and any specific conditions, which are necessary.
5.3.2 Thermal conductivity
Thermal conductivity shall be determined in accordance with EN 14063-1.
Table 1 —Test methods, test specimens and specific conditions
Clause
No. Title Test method Minimum number of Specific
test specimens to conditions
get one test result
4.2.1 Loose bulk density EN 1097-3 3
4.2.2 Particle size distribution EN-933-1 1
4.2.3 Reaction to fire EN 13820 See Annex ZA, reaction to fire class A1
without testing
(organic content)
4.3.2 Thermal conductivity In accordance with 14063-1
4.3.4 Particle density EN 1097-6, Annex C 2
4.3.5 Water content EN 1097-5 3 Not applicable for
ITT
4.3.6 Water absorption EN 1097-6, Annex C 2
4.3.7 Compressibility and compressive Compressibility and 3
strength compressive strength
(EN13055-2, Annex A)
4.3.8 Compressive creep Annex C 3
4.3.9 Shear strength –static loading Annex A 4
4.3.10 Cyclic compression Annex B 2
4.3.11 Shear strength –cyclic loading EN 13286-7 3
4.3.14 Chemical content EN 13055-2 1
4.3.15 Freezing and thawing resistance EN 13055-2, 3
Annex B
4.4.1 Crushing resistance EN 13055-1, Annex A 3
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prEN 15732:2007 (E)
6 Designation code

A designation code for the product shall be given by the manufacturer. The following shall be included except

when there is no requirement for a property described in 4.3:
Abbreviated term
– Expanded clay LWA Exp. clay LWA
– This EN standard number
prEN 15732
– Loose bulk density
LD “i”
– Particle size PS “i”

The designation code according to this standard for an expanded clay lightweight aggregate product is

illustrated by the following example:
Exp. clay LWA prEN 15732 – LD250 – PS(8-20)
7 Evaluation of conformity

The manufacturer or the authorised representative established in the EEA shall be responsible for the

conformity of his product with the requirements of this document. The evaluation of conformity shall be carried

out in accordance with EN 13172 and shall be based on initial type testing (ITT), factory production control

(FPC) by the manufacturer, including product assessment and tests of samples taken from the factory.

ITT shall be carried out in accordance with EN 13172 for all characteristics declared, as listed in Table 1.

FPC shall be made for the characteristics listed in Annex D.

If a manufacturer decides to group his products it shall be done in accordance with EN 13172.

The minimum frequencies of tests in the factory production control shall be in accordance with Annex D, Table

D.1. When indirect testing is used, the correlation to direct testing shall be established in accordance with

EN 13172.

The manufacturer or the authorized representative shall make available, in response to a request, a certificate

or declaration of conformity as appropriate.

NOTE For the EC certificate and declaration of conformity, as appropriate, see ZA.2.2.

8 Marking and labelling

Products conforming with this standard shall be clearly marked on the label on the packaging or on an

accompanying document, with the following information:
– product name or other identifying characteristic;

– name or identifying mark and address of the manufacturer or his authorised representative;

– date of delivery, manufacturing plant and/or traceability code;
– reaction to fire class
– designation code as given in clause 6;
– quantity of material, in m .
NOTE For CE marking and labelling see Annex ZA.3.
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prEN 15732:2007 (E)
Annex A
(normative)
Test for mechanical and physical properties of expanded clay LWA -
Triaxial Test for determination of shear strength properties
Foreword

This draft of static triaxial test for expanded clay LWA is based on the Draft European Standard, which

specifies a procedure for determining the behaviour of unbound mixtures of natural and artificial aggregates

used in road structures.
A.1 Scope

This test description specifies a triaxial test method for determination of strength and deformation properties of

expanded clay LWA and similar products. In a triaxial test an axial deviator stress and a static confining cell

pressure are imposed on a cylindrical specimen of the material. The test procedure shall simulate relevant

conditions and stress states for these materials, for example as found in layers beneath the surface of a

pavement section or structure.

This method is applicable to specimens prepared by compaction in the laboratory, where various compaction

methods may be used to obtain the wanted porosity. This method applies to mixtures, in which all particles

have a maximum size of 1/5 of the specimen diameter.

The test methods provide stress paths and tables and plots of stress versus strain. The test results are used

to interpret the strength properties (friction angle φ and cohesion c) of the expanded clay LWA aggregate

under a variety of test conditions, such as different moisture and stress states. The properties determined with

this procedure can be used with classical procedures of limit state soil mechanic to establish the stability or

bearing capacity of the structure.

The resilient properties (Young's modulus and Poisson ratio) determined with this procedure can accordingly

be used with currently established linear elastic layered system theories to calculate the structural responses

of pavement structures.

The development of relationships to aid in interpreting and evaluating test results is left to the engineering or

office requesting the test.
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prEN 15732:2007 (E)
A.2 Definitions, symbols and abbreviations

For the purposes of this test description the following definitions and symbols in Table A.1 apply.

Table A1 — Symbols and definitions
Symbol Definition Explanation and equations Unit
Normal stress kPa
σ Total axial stress, major principal kPa
stress in active compression tests
Total radial stress, minor and i.e. the applied confining pressure in kPa
intermediate principal stress in active the triaxial chamber or the vacuum
compression tests inside the specimen when no triaxial
chamber is used
Deviatoric stress i.e. difference between total axial and kPa
total radial stress in compression test
P Mean normal stress kPa
p = (σ + 2 * σ )/3
1 3
Linear strain %
ε ∆h / H , H = the total height or the
0 0
gage length
Resilient or recovered axial strain %
Permanent axial strain %
Resilient or recovered radial strain %
Permanent radial strain %
r r r r
Resilient or recovered volumetric strain %
ε ε = ε + 2 * ε
v v 1 3
p p p p
Permanent volumetric strain %
ε ε = ε + 2 * ε
v v 1 3
r r r r
Resilient or recovered shear strain %
ε ε = 2 * (ε - ε )/3
q q 1 3
p p p p
Permanent shear strain %
ε ε = 2 * (ε - ε )/3
q q 1 3
Change in linear strain %
dt Change in time s
E Resilient modulus kPa
Poisson ratio -
Friction angle
Cohesion kN/m
Dry density kg/m
Maximum dry density kg/m
dmax
A.3 Test principle

The triaxial test is used to determine the strength properties (friction angle φ and cohesion c) of expanded clay

LWA. In static triaxial tests a monotonic axial deviator stress and a static confining cell pressure are imposed

on a cylindrical unbound specimen of the material to simulate the average stress range in an unbound layer or

structure. For the determination of these properties, no pre-conditioning phase is needed. The specimen has

to be tested at known density and moisture condition.

This test provides a means of evaluating the properties of expanded clay LWA materials, under a variety of

test conditions, such as different moisture and stress states, that realistically simulate the conditions that exist

in pavements or structures.

It is not possible to study the permanent behaviour of material with this test procedure.

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prEN 15732:2007 (E)

NOTE The resilient properties provide the basic constitutive relationship between stresses and resilient strains of

flexible pavement construction materials for use in structural analysis of multilayer pavement systems.

NOTE There are certain limitations inherent in using triaxial tests to simulate the stress and strain conditions of the

unbound mixture in the field when a wheel moves over the surface of a pavement.

NOTE Non-uniform stress conditions within the test specimen are imposed by the specimen end plates.

NOTE It has been shown that different methods of reconstituting specimens to the same density may result in

significantly different deformation properties. Hence the preparation method is important.

A.4 Apparatus
A.4.1 Triaxial apparatus
A.4.2 Triaxial test with cell

The pressure chamber capable for testing of expanded clay LWA are similar to most standard triaxial cells,

except that they are somewhat larger to facilitate larger samples and the internally mounted load and

deformation measuring equipment. The cells should allow for additional outlets for the electrical leads from the

measuring devices. An example of a triaxial test apparatus and the corresponding terminology is given in

Figure A1.

Air, water or silicon oil may be used as the chamber fluid. Water is suitable only if the electrical cables and

connections of the instrumentation are fully sealed.
A.4.3 Triaxial test with
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