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European Union Brite EuRam III

Light Weight Aggregates

EuroLightCon

Economic Design and Construction with

Light Weight Aggregate Concrete

Document BE96-3942/R15, June 2000

Project funded by the European Union

under the Industrial & Materials Technologies Programme (Brite-EuRam III)

Contract BRPR-CT97-0381, Project BE96-3942

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The European Union Brite EuRam III

Light Weight Aggregat es

EuroLightCon





Although the project consortium does its best to ensure that any information given is accurate, no liability or responsibil-

ity of any kind (including liability for negligence) is accepted in this respect by the project consortium, the authors/editorsand those who contributed to the report.

Acknowledgements

This report is an overall publication on LWA from Task 2 Light weight aggregates. The participants of task 2 were:Edda Lilja Sveinsdttir (IBRI, Task Leader), Arne Monsen (ExClay Int.), Erich Kwint (Vasim) and Karl-Christian Thienel(Lias Franken)

Information

Information regarding the report:Edda Lilja Sveinsdottir, Icelandic Building Research Institute, RB Keldnaholt, IS-112 Reykjavik, Iceland

Tel. +354 5707311, e-mail [email protected] regarding the project in general:

Jan P.G. Mijnsbergen, CUR, PO Box 420, NL-2800 AK Gouda, the NetherlandsTel: +31 182 540620, e-mail: [email protected]

Information on the project and the partners on the Internet: http://www.sintef.no/bygg/sement/elcon

ISBN 90 376 0118 9

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The European Union Brite EuRam III

Light Weight Aggregat es

EuroLightCon





Selmer Skanska AS, NOSINTEF, the Foundation for Scientific and Industrial Research at the

Norwegian Institute of Technology, NONTNU, University of Technology and Science, NO

ExClay International, NOBeton Son B.V., NL

B.V. VASIM, NLCUR, Centre for Civil Engineering Research and Codes, NLSmals B.V., NL

Delft University of Technology, NLIceConsult, Lnuhnnun hf., IS

The Icelandic Building Research Institute, ISTaywood Engineering Limited, GB

Lias-Franken Leichtbaustoffe GmbH & Co KG, DEDragados y Construcciones S.A., ES

Eindhoven University of Technology, NLSpanbeton B.V., NL

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BE96-3942 EuroLightCon 3

Table of Contents

PREFACE 4

SUMMARY 7

1 INTRODUCTION 8

2 NEW LWA MATERIALS 9

3 LWA PRODUCTS DATA SHEETS 11

3.1 General 113.2 Pumice and scoria 11

3.3 Expanded clay 113.4 Expanded glass 123.5 Expanded Shale and slate 123.6 Sintered and cold-bound Fly-ash 123.7 Blast furnace slag 12

4 TEST METHODS FOR LWA (CEN AND OTHER METHODS) 13

5 TESTING OF SELECTED TYPES OF LWA 16

6 RESULTS AND DISCUSSION 176.1 General 176.2 Results of LWA testing at IBRI 176.3 Results of LWA testing at Vasim 186.4 Results of LWA testing at ExClay 206.5 Results of LWA testing at Lias-Franken 206.6 Discussion 216.6.1 Freeze-thaw tests on LWA 216.6.2 Water absorption 22

6.6.3 Particle strength crushing resistance 236.6.4 Alkali-silica reactivity testing 236.6.5 General on requirements of LWA for structural concrete 23

7 REFERENCES 24

8 NOMENCLATURE 25

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PREFACEThe lower density and higher insulating capacity are the most obvious characteristics of Light-Weight Aggregate Concrete (LWAC) by which it distinguishes itself from ordinary NormalWeight Concrete (NWC). However, these are by no means the only characteristics, which jus-tify the increasing attention for this (construction) material. If that were the case most of the de-sign, production and execution rules would apply for LWAC as for normal weight concrete,without any amendments.

LightWeight Aggregate (LWA) and LightWeight Aggregate Concrete are not new materials.

LWAC has been known since the early days of the Roman Empire: both the Colosseum and thePantheon were partly constructed with materials that can be characterised as lightweight aggre-gate concrete (aggregates of crushed lava, crushed brick and pumice). In the United States, over100 World War II ships were built in LWAC, ranging in capacity from 3000 to 140000 tons andtheir successful performance led, at that time, to an extended use of structural LWAC in build-ings and bridges.

It is the objective of the EuroLightCon-project to develop a reliable and cost effective designand construction methodology for structural concrete with LWA. The project addresses LWAmanufactured from geological sources (clay, pumice etc.) as well as from waste/secondary ma-terials (fly-ash etc.). The methodology shall enable the European concrete and construction in-

dustry to enhance its capabilities in terms of cost-effective and environmentally friendly con-struction, combining the building of lightweight structures with the utilisation of secondary ag-gregate sources.

The major research tasks are:Lightweight aggregates: The identification and evaluation of new and unexploited sources spe-cifically addressing the environmental issue by utilising alternative materials from waste. Fur-ther the development of more generally applicable classification and quality assurance systemsfor aggregates and aggregate production.Lightweight aggregate concrete production: The development of a mix design methodology toaccount for all relevant materials and concrete production and in-use properties. This will in-clude assessment of test methods and quality assurance for production.Lightweight aggregate concrete properties: The establishing of basic materials relations, theinfluence of materials characteristics on mechanical properties and durability.Lightweight aggregate concrete structures: The development of design criteria and -rules withspecial emphasis on high performance structures. The identification of new areas for applica-tion.

The project is being carried out in five technical tasks and a task for co-ordination/managementand dissemination and exploitation. The objectives of all technical tasks are summarised below.Starting point of the project, the project baseline, are the results of international research work

combined with the experience of the partners in the project whilst using LWAC. This subject is

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dealt with in the first task.Tasks 2-5 address the respective research tasks as mentioned above: the LWA itself, productionof LWAC, properties of LWAC and LWAC structures.

Sixteen partners from six European countries, representing aggregate manufacturers and suppli-ers, contractors, consultants research organisations and universities are involved in the Eu-roLightCon-project. In addition, the project established co-operation with national clusters andEuropean working groups on guidelines and standards to increase the benefit, dissemination andexploitation.

At the time the project is being performed, a Working Group under the international concreteassociationfib (the former CEB and FIP) is preparing an addendum to the CEB-FIP Model Code1990, to make the Model Code applicable for LWAC. Basis for this work is a state -of-the-artreport referring mainly to European and North-American Standards and Codes. Partners in theproject are also active in thefib Working Group.

General information on the EuroLightCon-project, including links to the individual project part-ners, is available through the web site of the project: http://www.sintef.no/bygg/sement/elcon/

At the time of publication of this report, following EuroLightCon-reports have been published:R1 Definitions and International Consensus Report. April 1998R1a LightWeight Aggregates Datasheets. Update September 1998R2 LWAC Material Properties State-of-the-Art. December 1998R3 Chloride penetration into concrete with lightweight aggregates. March 1999R4 Methods for testing fresh lightweight aggregate concrete, December 1999R5 A rational mix design method for lightweight aggregate concrete using typical UK ma-

terials, January 2000R6 Properties of Lytag-based concrete mixtures strength class B15-B55, January 2000R7 Grading and composition of the aggregate, March 2000R8 Properties of lightweight concretes containing Lytag and Liapor, March 2000R9 Technical and economic mixture optimisation of high strength lightweight aggregate

concrete, March 2000R10 Paste optimisation based on flow properties and compressive strength, March 2000R11 Pumping of LWAC based on expanded clay in Europe, March 2000R12 Applicability of the particle-matrix model to LWAC, March 2000R13 Large-scale chloride penetration test on LWAC-beams exposed to thermal and hygral

cycles, March 2000R14 Structural LWAC. Specification and guideline for materials and production, June 2000R15 Light Weight Aggregates, June 2000R16 In-situ tests on existing lightweight aggregate concrete structures, June 2000R17 Properties of LWAC made with natural lightweight aggregates, June 2000R18 Durability of LWAC made with natural lightweight aggregates, June 2000R19 Evaluation of the early age cracking of lightweight aggregate concrete, June 2000R20 The effect of the moisture history on the water absorption of lightweight aggregates,

June 2000R21 Stability and pumpability of lightweight aggregate concrete. Test methods, June 2000R22 The economic potential of lightweight aggregate concrete in c.i.p. concrete bridges,

June 2000

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R23 Mechanical properties of lightweight aggregate concrete, June 2000R24 Prefabricated bridges, June 2000R25 Chemical stability, wear resistance and freeze-thaw resistance of lightweight aggregate

concrete, June 2000

R26 Recycling lightweight aggregate concrete, June 2000R27 Mechanical properties of LWAC compared with both NWC and HSC, June 2000R28 Prestressed beams loaded with shear force and/or torsional moment, June 2000R29 A prestressed steel-LWAconcrete bridge system under fatigue loadingR30 Creep properties of LWAC, June 2000R31 Long-term effects in LWAC: Strength under sustained loading; Shrinkage of High

Strength LWAC, June 2000R32 Tensile strength as design parameter, June 2000R33 Structural and economical comparison of bridges made of inverted T-beams with top-

ping, June 2000R34 Fatigue of normal weight concrete and lightweight concrete, June 2000

R35 Composite models for short- and long-term strength and deformation properties ofLWAC, June 2000

R36 High strength LWAC in construction elements, June 2000R37 Comparison of bridges made of NWC and LWAC. Part 1: Steel concrete composite

bridges, June 2000R38 Comparing high strength LWAC and HSC with the aid of a computer model, June 2000R39 Proposal for a Recommendation on design rules for high strength LWAC, June 2000R40 Comparison of bridges made of NWC and LWAC. Part 2: Bridges made of box beams

post-tensioned in transversal direction, June 2000R41 LWA concrete under fatigue loading. A literature survey and a number of conducted

fatigue tests, June 2000R42 The shear capacity of prestressed beams, June 2000R43 A prestressed steel-LWA concrete bridge system under fatigue loading, June 2000

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SUMMARYThis report is an overall-report from the Task 2: Light Weight Aggregates (LWA), giving sum-marized information on the work involved in the task.

The over-all objective of the project that is directly involving aggregates was to develop a reli-able and cost-effective design and construction methodology for structural concrete with LWAof natural (pumice) as well as artificial aggregates (expanded clay or flyash).

The project work program contained the main innovation claimed for LWA:

1. The improvement of production processes regarding the cost, energy consume and friendli-ness to the environment.

2. Further development of LWA from waste materials.3. A classification system offering a correct and generally applicable relation between aggre-

gate properties and concrete performance.

According to this, Task 2 was performed. The following chapters address these issues; startingwith chapter 2 on the development of new LWA made from by-products or waste. This work isdescribed in details in the Proceedings of the Second International Conference on StructuralLightweight Aggregate Concrete (Kristiansand, 2000) and is only briefly told here.

Chapter 3 - LWA data sheets is a summary from the baseline report, sub-task 1.1, report BE96-3942/R1A, where data sheets of the commercially available LWAs that are produced in Europeare listed.

Chapter 4 test methods for LWA (CEN and other methods) - describes the current status of thestandardization work being carried out by the CEN. Other, national test methods used for LWAare also described.

Chapter 5 testing of selected types of LWA gives an overview of the testing that each part-ner of Task 2 performed on LWA.

Chapter 6 results and discussion is a discussion on the results obtained and the test methodsgiven a critical view.

Keywords

Lightweight aggregates (LWA), test methods for LWA, new LWA materials

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1 INTRODUCTIONThis report is an overall publication on LWA from Task 2: Lightweight aggregates, to be usedfor dissemination of results from this task.

The following objectives of the project are directly related to the LWA:To develop a reliable and cost-effective design and construction methodology for structuralconcrete with LWA of natural (pumice) as well as manufactured aggregates (expanded clay orsintered fly ash).

To further develop, improve and utilize the option of converting by-products or pollutants

into LWA. To reduce the depletion of traditional aggregate sources by further developing and improv-

ing the technology of utilizing natural sources.

To develop the application technology in order to obtain maximum utilization of the rawmaterials, i.e. to minimize the amount of waste from aggregate production.

The main innovation of the project that is claimed for LWA:

1. The improvement of production processes regarding the cost, energy consume and friendli-ness to the environment.

2. Further development of LWA from waste materials.

3. A classification system offering a correct and generally applicable relation between aggre-gate properties and concrete performance.

Task 2 was initially split up into three sub-tasks: Materials sources, environmental issues,Evaluation and classification system and Quality assurance for LWA production. The lastsub-task was later merged with the sub-task 3.3 Quality assurance for LWAC production andone report Structural LWAC. Specification and guideline for materials and production waspublished (BE96-3942/R14).

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2 NEW LWA MATERIALSSub-task 2.1 Materials sources, environmental issuescovered this part of task 2. Its objectivewas to identify and evaluate new and unexploited sources of raw materials for LWA productionthat can offer a combination of environmental and technical issues; i.e. utilizing waste and sec-ondary materials in a production of aggregates that can meet the relevant requirements for struc-

tural use.

Traditionally, concrete is being produced in close dependence on the quality of the aggregates -in the way nature and more or less adjusted/improved have provided this quality industrially.For LWAC there is a higher degree of industrial influence on the aggregate properties, but still a

significant dependence on the selection of good quality materials sources for production. How-ever, the total volume and the practical availability of acknowledged aggregate sources is rap-idly decreasing, at the same time as the volume of urban and industrial waste and secondary ma-terials is becoming an increasing matter of concern in great parts of Europe. Already successfulinitiatives have been taken by the concrete, cement and LWA industry to convert such secon-dary products into construction materials.

Most types of the LWAs that are used by the construction industry today are manufactured ma-terials, made from natural resources like clay and slate or from industrial by-products such as flyash and glass. The products are commercially available LWAs such as Leca, Solite (USA), Lia-por and Lytag.

In order to find potential new LWAs, some by-products and waste materials were tested in theproduction lines of Vasim in the Netherlands. Traditionally they produce Lytag, a type of sin-tered fly ash.

The work covers the following items:

The history of LWA production including the available materials, production methods andidentified re-uses of wastes in LWA production.

Identification of resources their locations, health risk regarding their production, commer-cial value and evaluation of the materials

Production of new LWA, reporting the trials and mix design and production methods Results of the production trials including specification of the new materials, health risk re-

garding leaching, manufacturing and evaluation for each application

Technology of the production of new LWA that covers suitable production methods on re-use of waste, investments and commercial consequence, recommendations and evaluation

The new LWA materials produced by Vasim were made from the following raw materials:

1. Fly-ash from burnt silt of sewage works2. Fly-ash from incineration of refuse3. Fly-ash from bio-mass conversion

4. Fly-ash from incineration of paper residue

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5. Pumice fines6. Spoil from polluted dredged harbours, rivers and canals7. Silt from quarries/sea gravel8. Silt from recycled concrete

9. Silt from water treatment works

Materials number 2, 4 and 6 were only produced in a laboratory scale as it was later decided thattheir full-scale production would never be allowed because of environmental issues. The otherpartners of task 2 did thus not test these LWAs.

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3 LWA PRODUCTS DATA SHEETS

3.1 GeneralIn the baseline report, report BE96-3942/R1a, most of the commercially available LWAs arelisted, that are produced in Europe. A datasheet is given for each material.

The data sheets contain information regarding:1. commercial name2. supplier/manufacturer3. general properties

4. densities5. crushing resistance6. water absorption7. loss on ignition8. chloride content9. sulphate content10.chemical composition11.production location12.number of years of experience of application in concrete

The following LWA products are listed in the document and classified according to their origin

/ process method:

3.2 Pumice and scoria Vikur (from Snfellsjokull) sizes 1-4 and 4-16 mm, supplier: Nesvikur, Iceland Hekla pumice, sizes 0-10, 4-16mm, supplier: Pumice Products Ltd., Iceland

Hekla pumice, F 8/16 W, B 0/9 W, F 0/8 W, supplier: Jarefnainaur hf., Iceland

Scoria, size 0-100 mm, supplier: AMC Lettsteinn ehf, Iceland

3.3 Expanded clay Ares, types 4, 5, 6, 8, supplier: Cementi Buzzi, Italy Argex, types 0.5/4, 4/10, 10/16, supplier; N.V. Gralex, Belgium

Arlita, types F3, F5, F7, A5, F3/3-8, F3/3-6, F5, F7, G3, A4g, A5m, supplier: Aridos Lig-

eros, S.A., Spain

Fibo, sizes 0-2, 2-4, 4-8, 8-16 mm both crushed and closed cubic rounded, supplier: FiboExClay Deutschland GmbH, Germany

Leca Austria, types NW 0-2, 0-4, NW 1-4 RK, NW 2-4, NW 4/8, HD 4/8, NW 8/12, HD8/12, supplier: sterreichische Leca Gestellschaft GmbH, Austria

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Liapor, types CS 0-4, CS 4-8, CS 8-16 K-Sand, supplier: Lias-Vintirov, Czhechia

Liapor, types 3, 4, 5, 6 (4-8), 6 (8-16), 6.5, 7, 8, 9.5, supplier: Lias-Franken LeichtbaustoffeGmbH and Lias Leichtbaustoffe Tuningen GmbH, Germany

Fibo, types 0-4 crushed, 4-8 mm DIN, supplier: Fibo Vrket, Denmark

KS 810 (8-10) and KS (10-20), supplier: Optiroc Oy Ab, Finland Leca, types 600 (4-12 mm), 700 (4-12 mm), 800 (4-12 mm), 600 Borge 4-12 mm,

Lttklinker 4-10 mm, LWA 2-4 mm, LWA 4-10 mm, LWA 10-20 mm, supplier: a.s. NorskLeca, Norway

3.4 Expanded glass Liaver, sizes 0.25-0.5, 0.5-1.0, 1-2, 2-4, supplier: Liaver, Germany

Poraver, sizes 0.25-0.5, 0.5-1.0, 1-2, 2-4, 4-8, supplier: Dennert Poraver GmbH,

Germany

3.5 Expanded Shale and slate Berwilit, sizes 0-2, 0-4, 2-4, 4/8 N, 4/8 S, 8/16 N, 8/16 S, supplier: Wittgensteiner

Blhschiefer GmbH & Co KG, Germany

Granulex, types 0.5/4, 4/10, 8/12, 10/20, 15/25, supplier: GEM, France Stalite, types 0.15/5, 1/13, 2/19, 5/25, supplier: Carolina Stalite Company, USA

Ulopor, sizes 0-2, 2-4, 4-8, 8-16, supplier: VTS GmbH, Germany

3.6 Sintered and cold-bound Fly-ash Aardelite, types 1400 2-4 I, 1430 4-8 I, 1400 4-16 I, 1430 8-16 I, supplier: Provag B.V.,

The Netherlands Fa-Light 5-15, supplier: Kyushu, Kyundensangyo, Kobe Steel, Japan

Lytag, types L2 Fines, 4-8 mm Granular, 4-12 mm Granular, 6-12 mm Granular, supplier:Lytag, United Kingdom

Lytag, types 0.5/4, 0.5/6, 0.5/8, 0.5/12, 4/8, 4/10, 4/12, 6/12, supplier: B.V. Vasim, TheNetherlands

Pollytag, types 0.5/4, 4/8, 4/12, 6/12, supplier: Pollytag SA, Poland

3.7 Blast furnace slag Grobalith, types 0-4 and 0-4 S (crushed), supplier: BauMineral GmbH, Germany

Safamolith, types 0/4 vA, M 0/4 vA, supplier: Safa Saarfilterasche-Vertriebes-GmbH,Germany

Steasint 0/4, supplier. Steag Entsorgungs-GmbH, Germany

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4 TEST METHODS FOR LWA (CEN AND OTHER METHODS)

The LWA will normally exhibit, in contradiction to other aggregates, higher permeability andporosity as well as lower strength and rigidity than the cementitious paste. Thus, the LWA willplay the major role with respect to concrete properties. Concrete density is a principal parameterand determined by the LWA used. For the concrete producer, a need is for more thorough in-formation on the aggregate. The great variety of materials, spanning manufactured aggregatesfrom a variety of sources - geological and waste deposits, natural deposits, further underlines theneed of a classification system.

One of the major objectives of Task 2 on LWA was to develop a classification and evaluationsystem being applicable for all types of LWA, regardless of sources and production technologyapplied. The system shall enable the industry to choose the cheapest LWA that fulfils the re-quired properties in any case. The material characteristics needed will be specified as well as thetest methods and quality criteria for the different LWA classes.

This objective was later changed to: to use the impact of the project to ensure that the classif i-cation and evaluation system being drafted by the TC-154- group on LWA (SC-5), will cover alltypes The reason for that decision was that the CEN-committee on LWA, called CEN/TC-154/SC-5, had been working on a standard for LWA since 1995 and the final standard fromthem is due by the year 2003. It was thus felt that the ELC project should not duplicate the work

of this committee, rather use its resources to ensure that the draft would cover all LWA types forstructural concrete.

The latest version of the proposed production standard for LWA, prEN 13055-1 for concrete,mortar and grout, is from February 2000, Doc. N 387. It specifies the properties and technicalrequirements for LWA, with the note that additional requirements may prove to be necessary forrecycled materials.

It should be pointed out that all the test methods referred to in the prEN 13055-1 are designedfor normal weight aggregates (NWA), except a method for freezing and thawing that has beenfound to be suitable for some LWA. The method is described in prEN 13055-2 (Lightweightaggregates for unbound and bound applications excluding concrete, mortar and grout) Annex C.

The test methods referred to in prEN 13055-1 are listed here below and they are described anddiscussed where necessary.

EN 932-1. Tests for general properties for aggregates. Part 1: Methods for sampling.

prEN 932-2. Tests for general properties of aggregates. Part 2: Methods for reducing laboratory

samples.

prEN 932-5. Tests for general properties of aggregates. Part 5: Common equipment and cali-

bration.

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prEN 933-1. Tests for geometrical properties of aggregates. Part 1: Determination of particle

size distribution Sieving method.

prEN 933-2. Tests for geometrical properties of aggregates. Part 2: Determination of particle

size distribution Test sieves, nominal size of apertures.

prEN 933-10. Tests for geometrical properties of aggregates. Part 10: Determination of fines

grading of fines grading of fillers (air jet sieving).

prEN 1097-3. Tests for mechanical and physical properties of aggregates. Part 3: Determination

of loose bulk density and voids.


of the water content by drying in a ventilated oven.


of particle density and water absorption.

The description of this test method is the following: The test portion is dried in anoven at 110C to constant mass, and allowed to cool to ambient temperature. The ma-terial is then placed in pre-weighted pyknometer and weighted. The pyknometer isthen filled up with water at 22 +/- 1C and the aggregate is gently stirred by rollingand tapping the pyknometer. The water filled pyknometer with the test sample is thenweighted, and placed in a water bath at 22 +/- 1C. The operation is repeated after 2 hand 24 h.This test method and its limits are discussed further in chapter 6.

prEN 1744-1. Tests for chemical properties of aggregates. Part 1: Chemical analysis.

ISO 3310-1: 1990. Test sieves Technical requirements and testing. Part 1: Test sieves of

metal wire cloth.

ISO 3310-2: 1990. Test sieves Technical requirements and testing. Part 2: Test sieves of per-

forated metal plate.

prEN 13055-2. Lightweight aggregates for bituminous mixtures and surface treatments and for

unbound and bound applications excluding concrete, mortar and grout. Annex C: Guidance on

the freezing and thawing resistance of lightweight aggregates.

This proposal for a frost resistance test is derived from the German (DIN 52104-1)

freeze-thaw test. A test portion of LWA, having been soaked in water at atmosphericpressure, is subjected to 20 freeze-thaw cycles. This involves cooling down to below 15C in air and then thawing in a water bath at about 20C. After completion of thefreeze-thaw cycles, the LWAs are examined for any changes such as crack formationand/or loss in mass. The method differs from the earlier proposed prEN1367-1:1996method for normal weight aggregates, that involves freezing down to 17,5 C in iceand has on the other hand only 10 freeze-thaw cycles.The freeze-thaw tests on LWAs are discussed in chapter 6.

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prEN 13055-1. Lightweight aggregates for concrete, mortar and grout. Annex A: Determination

of a crushing resistance index. Determination of crushing resistance.

A sample is placed in a steel container and compacted by vibration. The test is thenperformed as an unconfined compression test where the load is continuously applied.

The force required is measured and expressed as the resistance to crushing. Furtherdiscussion is in chapter 6.

prEN 13055-1. Lightweight aggregates for concrete, mortar and grout. Annex B: Determination

of resistance to disintegration.

Until the proposed CEN-test methods will be adapted by most of the European coun-tries, different test methods for LWA are used in each country. The test methods thatwere used in this project and are not listed above, are as follows:

Freeze-Thaw resistance (prEN 1367-1:1996)

Test portion of single sized aggregates, having been soaked in water at atmosphericpressure, for 24 hours, is subjected to 10 freeze-thaw cycles. This involves cooling to17,5C under water and then thawing in a water bath at about 20C. After completionof the freeze-thaw cycles, the aggregates are examined for any changes (crack forma-tion, loss in mass, and if appropriate, changes in strength). The limits for frost resistantconcrete are

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5 TESTING OF SELECTED TYPES OF LWAIn order to obtain comparison between the LWA types used in the project, at least one type ofLWA was selected from each category of the commercially available materials and each of thenew materials from Vasim were tested as well. The partners from Tasks 2 and 3 did each severaltests on the same and/or different materials. Table 1 shows the selection of materials and wherethey were tested.

The task was split between the partners such that the new materials were all tested by Vasim andthen double-tested by the other partners, except material number 3, which was only tested by Va-sim. At IBRI, at least one type of each LWA was run through all the proposed LWA tests of prEN

13055-1 and the results from the producers are obtained on their own materials according to theprEN 13055-1 and/or their own, local methods.

The reason for this testing scheme was to obtain a good comparison by running all these LWAmaterials through the proposed CEN-standard methods, compare the results to the currently usedmethods and point out the differences/complications if any occurred.

Table 1. Selection of LWA materials tested

LWA- materials ExClay IBRI Lias-Franken Vasim

Leca 290 (ord) 4-10 mm, round x

Leca 700 4-8 and 8-12 mm xLeca 800 4-8 and 8-12 mm x

Liapor 3 4-8 mm x

Liapor 4 4-8 and 8-16 mm x

Liapor 5 4-8 x

Liapor 8 4-8 x

Liapor 9.5 4-8 x

Solite USA 4-16 mm x

Seyishla-scoria 4-8 and 8-12 mm xHekla pumice x

Snfellsjkull pumice xLytag (UK) 4-12 mm x

Lytag (NL) 0.4-4, 4-8, 6-12 mm x x

New material Vasim no. 1 x x

New material Vasim no. 3 x



New material Vasim no. 8 x x xNew material Vasim no. 9 x x

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6 RESULTS AND DISCUSSION

6.1 GeneralAll test results are listed in this chapter, as tested by the different partners, set up in separate

tables. The results are discussed in chapter 6.6.

6.2 Results of LWA testing at IBRI

Table 2. Measurements made at IBRI according to test methods in prEN-13055 and others asindicated:

Materials/

Test methods

PumiceH

(4-8)

PumiceS

(4-16)

Scoria

(0-64)

Liapor 8

(4-8)

Lytag UK

(4-12)

Vasim 5

(4-8)

Vasim 8

(4-8)

Vasim 9

(4-8)

Solite US

(4-16)

Loose bulk(kg/m3)

304 368 693 807 765 793/825

954 937 769

Particle density(kg/dm3)

0,8 1,6 1,9 1,5 1,6 1,5 1,7 1,6 1,4

Moisture (%) 110 54 18 20 11 28,5 27,2 20,9 6,3

24 hr water

absorpt. (%)

19,3 9,9 6,3 12,1 8,6 21,8 10,8 11,9 8,4

Crushingresistance. (N/mm2 )

15,2 14,4 19,4

Freeze-thawresist. (%)prEN1367

1,9 1,4 0,2 0,6 0,7 1,7 0,3 0,1 0,2

Freeze-thawresist. (%) Nordtest

0,0 0,1 0,0 0,3 0,4 9,7 0,0 0,0 0,0

Freeze-thawresist. (%) DIN

3,0 2,4 0,9 0,9 1,0 1,7 - 0,4 0,4

Alkali reactivity(%exp.) ASTM

0,019 0,042 0,034 0,057 0,036 0,043 0,009 0,018 0,052

Resistance todisintegration (%) 2,26 1,39 0,98 0,25 2,23 0,14 0,3 0,3 0,45

Chloridecontent (%)

0,0037 0,0024 0,0008 0,0017 0,0022 0,0036 0,0014 0,0004

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6.3 Results of LWA testing at Vasim

Table 3. Results of LWA testing and concrete mix tests at Vasim on all new materials and Lytag

basic production

LWA-Materials Vasim 1

4-8 mm

Vasim 1

8-16 mm

Vasim 3

4-8 mm

Vasim 3

6-12 mm

Vasim 5

4-16 mm

Vasim 7

4-12 mm

Vasim 8

4-12 mm

Vasim 9

4-12 mm

Loose bulk density [kg/m] 840 850 710 720 720 780 740 760

Particle density [kg/m] 1470 1480 1360 1370 1230 1460 1370 1400

Particle geometry Clo-sphr Clo-sphr Clo-sphr Clo-sphr Clo-sphr Clo-sphr Clo-sphr Clo-sphr

Aggregate size 4-8 mm 8-16 mm 4-8 mm 6-12 mm 4-16 mm 4-12 mm 4-12 mm 4-12 mm

Particle size distribution

Sieve (mm), rest %

20 - - - 0 - - -

16 - 0 0 16 0 0 0

12,5 0 29 0 7 33 2 5 0

8 5 92 3 85 62 69 64 41

6,3 - - 29 97 77 92 87 84

5,6 - - 49 97 84 95 91 91

4 93 99 92 98 96 98 96 96

2 99 100 97 98 99 98 97 98

1

0,5

0,125

Fines, < 0,063mm 0,5 0,4 2 1 0,3 1 2 1

Water absorption

30 minutes [% by mass] 31 30 14 16 24 13 16 14

24 hours [% by mass] 33 32 15 19 25 15 18 16

Crushing resistance

NEN 3543 5,2 MPa 4,8 MPa 5,5 MPa 5,0 MPa 5,1 MPa 7,0 MPa 6,1 MPa 6,8 MPa

Concrete mix-test

Cement: CEM I 32,5 R 320 kg 320 kg 320 kg 320 kg 320 kg 320 kg

W/c ratio: 0,47 150 litre 150 litre 150 litre 150 litre 150 litre 150 litre

Sand : 40% 761 kg 761 kg 761 kg 761 kg 761 kg 761 kg

LWA : 60% 213 kg 425 kg 205 kg 384 kg 530 kg 629 kg 590 kg 603 kg

Absorption water 61 litre 124 litre 30 litre 61 litre 143 litre 101 litre

Slump

Density kg/m (wet) 2054 kg 1911 kg 1904 kg 1961 kg 1928 kg 1937 kg

Cube strength 28 days 50,3 44,4 40,1 48,3 40,3 47,7

Tensile strength 28 days 3,5 3,2 3,2 3,6 3,0 3,5

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Table 3, continued

LWA-Materials Lytag

0,5-4 mm

Lytag

4-8 mm

Lytag

6-12 mm

Loose bulk density [kg/m] 780 780 760

Particle density [kg/m] 1420 1400Particle geometry Clo-sphr Clo-sphr Clo-sphr

Aggregate size 0,5-4 mm 4-8 mm 6-12 mm

Particle size distribution

Sieve (mm), rest %

20 - - -

16 - - 0

12,5 - 0 < 15

8 - < 15 % -

6,3 - - -

5,6 0 - > 85

4 < 15 > 85 -

2 55-75 > 97 >971

0,5 > 85

0,125

Fines, < 0,063mm < 5,0 < 2,0 < 2,0

Water absorption

30 minutes [% by mass] - 15 15

24 hours [% by mass] - 18 18

Crushing resistance

NEN 3543 - >5,0 MPa >4,0 MPa

Resistance to disintegration good good Good

Chloride content < 0,02 % < 0,02 % < 0,02 %

Sulphate content < 1,0 % < 1,0 % < 1,0 %Total sulphur content - - -

Loss on ignition < 5,0 % < 5,0 % < 5,0 %

Harmful components none none None

Concrete mix-test

Cement: CEM I 32,5 R 320 kg

W/c ratio: 0,47 150 litre

Sand : 32 % 622 kg

LWA : 68 % 177 kg 523 kg

Absorption water 32 litre 94 litre

Slump

Density kg/m (wet) 1918 kg

Cube strength 28 days 48,5Tensile strength 28 days 3,7

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6.4 Results of LWA testing at ExClay

Table 4. Leca materials and Vasims new materials 1, 7 and 8 tested at ExClay

Materials

Test method

L290

(4-10r)

L700

(4-8)

L700

(8-12)

L800

(4-8)

L800

(8-12)

asim 1

(8-16)

Vasim 7

(4-12)

Vasim 8

(4-10)Bulk density dry(kg/m3) prEN

291 669 659 803 772 825 748 810

Bulk density moist(kg/m3) prEN

322 670 660 805 775 1,65part-den

835 980

Moisture (%) prEN 10,7 0,1 0,2 0,2 0,4 29 11,6 211 hr water absorpt. (%) Ex-Clay method

9 10,1 10,1 7 9,4 28 15,7 11,6

24 hr water absorpt. (%)ExClay method

12 13,8 13,8 11 12,9 30 18,4 14,2

Filler (%)ExClay method 4,2 0 0,1 0,1 0,2 0 2,2 2,2

Fineness modulus ExClaymethod 6,24 5,75 6,69 5,75 6,7 6,75 6,21 6,12

Crushing resist. (N/mm2)ExClay meth

1,1 7,3 6,3 9,8 8,5 5,72 5,1 7

6.5 Results of LWA testing at Lias-Franken

Table 5. Liapor materials tested at Lias-Franken Leichtbaustoffe

Materials/

Test method

Liapor 3

(4-8)

Liapor 4

(4-8)

Liapor 5

(4-8)

Liapor 9.5

(4-8)Bulk density dry(kg/m3) prEN

327 414 490 922

Bulk density moist(kg/m3) prEN

331 420 503 945

Particle density(kg/dm3) prEN

0,61 0,79 0,91 1,65

Moisture (%) prEN 0,3 0,1 0,3 0,3

1 hr water absorpt. (%)prEN

12,5 10,8 8,0 6,5

24 hr water absorpt. (%)prEN

16,1 15,6 17,2 11,0

Crushing resist. (kN)DIN 4226-2

12,7 23,7 41,2 179,7

Crushing resist. (kN) prEN 14,5 28,3 55,1 325,3

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6.6 DiscussionResults that show the greatest difference between the test performed according to the proposedprEN 13055-1 and the national or local methods are from particle density and water absorptiontests as well as the crushing resistance tests. The relevance of these tests to concrete performanceis discussed in the Structural LWAC. Specification and guideline for materials and production-report BE96-3942/R14. Other tests that show different results are the three freeze-thaw tests thatwere carried out at IBRI.

6.6.1 Freeze-thaw tests on LWAAt some point during the work of CEN/TC154/SC5 on LWA, the freeze-thaw resistance methodprEN1367-1 was suggested to be used for LWA, but was then withdrawn from the draft of 13055-1. The reason for this is the following:The freeze-thaw method prEN 1367-1 is specially designed for normal weight aggregates. It ismostly based on the test method DIN-52 104, part 1, method N. The aggregates are submerged

in water and go through 10 cycles of freezing at -17,5 C and thawing at 20 C. This method isfully valid and has certain references to the performance of the final product made by normalweight aggregates (NWA), but does not seem to apply to the majority of LWA.

During this test, the LWA is totally submerged in water, thus saturating completely (or most of)the aggregate and when subject to - 17,5 C, the water expands when transformed to ice andbreaks the walls between the pores in the aggregate. NWA are not subjected to this harsh treat-ment as the water is not inside the sample, but only in what fractures might be there or otherweaknesses and therefore this test is excellent for this type of material to test its weaknesses.The porosity of a LWA is their benefit, not a weakness, and therefore most LWA in concrete, orother final structure, have good frost resistance as expected. Most LWAs designed for concrete

withstand very well the concrete freeze-thaw tests performed on them and LWAC have a recordof good durability even in harsh environments.

Several types of LWA that have been used for years and have proved good performance in theirfinal structures, fail the freeze-thaw test prEN 1367-1. These materials are for example naturalpumice and some types of Liapor and Leca.

In the latest version of prEN-13055-1 a new type of freeze-thaw test is included and requiredin the case of absence of long-term experience. This test is the method P of the German standardDIN-52 104, part 1 and is described here in chapter 4. Instead of testing the LWA submerged inwater/ice, it is frozen in air (after soaking in water) and thawed in a water bath. The cycles are20 instead of 10 and the freezing at 15 C instead of -17,5 C.

These two tests and the Nordtest method (see description in chapter 4) were all carried out onthe materials tested at IBRI. The results are summarized in figure 1.

It is obvious from the figure, that the tests do show different results. It should be pointed outthat on the legends in figure 1, the new prEN-13055-2 test is the same as DIN 52104-1. Thereason for these different results is both the different temperatures used, different number ofcycles and difference due to submerging in ice or air.

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An explanation for the higher breakdown of LWA in the new test is that the cycles are twiceas many as in the prEN-test and even though tested in air, the material is soaked in water priorto testing. This causes the more porous materials (natural materials that do not have a burnt,glassy surface) to absorb water that expands during the freezing cycles.

The freeze-thaw resistance tests of LWA have not any proven relation to their performance inconcrete and these tests should be used for production control only.

6.6.2 Water absorptionIt was discussed by the EuroLightCon-partners that the test results from this test method do notgive the concrete-producers the absorption information they require for their mix-design. Thismethod gives the initial reading after 5 minutes and then 2 and 24 hrs. The initial (before the 5minutes) absorption is thus lost information as the very porous LWA do absorb most of theirmoisture in the very first minutes after immersion in water. Furthermore the material is com-

pletely dried prior to testing, which is very rare in reality as the LWA are usually in some moistcondition. They are either drying out or in the wetting stage and their absorption behaviour de-pends on which moisture condition they actually possess (see also report R14).The test method does only cover materials in the size range 4-31.5 mm and no test on the sandfraction is given or referred to. Report R14 (Structural LWAC. Specification and guideline formaterials and production) discusses this and gives a reference to an alternative method for test-ing the particle density of LWA sand.

Figure 1. Difference between the three freeze-thaw tests performed on the LWAs at IBRI

Frost resistance

0,0

2,0

4,0

6,0

8,0

10,0

12,0

PumiceHLiapor8

Lytag Scoria PumiceSSolite Vasim5

Vasim8Vasim9

Weightloss(%

prEN 1367-1

NordtestDIN52104-1

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6.6.3 Particle strength crushing resistanceAs pointed out in the report R14 no method exists to measure the strength of LWA directly. In-stead the crushing resistance test is taken as an indirect measure for particle strength.

From the results presented in chapter 5.5 on Liapor material, it is obvious that the method usedhas a large impact on the results. There, both the prEN method is used and the method from theGerman LWA standard. The difference is large, and increases as the materials have highercrushing resistance. It was observed in addition, that the already high standard deviation for thestrength values was even higher for the new test procedure in prEN 13055-1 for strong sphericalLWA (e.g. Liapor 9.5). Thus it may be concluded that the new test gives sometimes less reliablethan the old test procedure.

It is also pointed out in the mentioned report that the crushing resistance should not be consid-ered for the prediction of concrete strength as in general; there does not exist any correlationbetween the crushing resistance and the concrete strength. The determination of crushing resis-

tance is intended only for production control.

6.6.4 Alkali-silica reactivity testingThe prEN 13055-1 does not give reference to any test method for alkali-silica reactivity, butbriefly discusses the phenomena. The potential alkali-silica reactivity is explained in the report3.3 and some methods discussed.

The ASTM-1260 test on alkali-silica reactivity has been used to measure the potential alkalireactivity of NWA as well as of LWA. It is measured on mortar bars made with the aggregate tobe tested. The bars are immersed in 1N-NaOH solution at 80C. The test takes only 14 days. It

has been considered to be a rather harsh test for determining if the aggregates are reactive ornot. The expansion limits are < 0,1 % for very good performance but if the sample shows morethan 0,2 % expansion they fail the test.

In task 2.2, nine samples of different types of LWA were tested according to ASTM-1260. Thematerials were chosen from each category: expanded clay, expanded glass and natural materialsas well as some experimental LWAs made of recycled materials (see table 2, chapter 8.2). Allsamples pass the test with very low expansions of only 0,01-0,06 %.

6.6.5 General on requirements of LWA for structural concrete

The producers in Task 2 all share the opinion that the information on the LWA itself is of im-portance, but only tells half the story of the LWA when incorporated in LWAC. Therefore thetests on LWA should be limited to basic needs for the mix-designer of the concrete and the pro-ducer should give information on the limits for their material instead. This is further explainedin report R14.

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7 REFERENCES

EuroLightCon. Baseline report data sheets. Report BE96-3942/1A, 1997

EuroLightCon. Structural LWAC. Specification and guideline for materials and production. Re-port BE96-3942/R14

CEN/TC154/SC5 DOC. N 387: Lightweight aggregate for concrete, mortar and grout prEN13055-1. Working document revised February 2000.

CEN/TC154/SC5 DOC. N 378: Lightweight aggregates. Part 2: Lightweight aggregates forunbound and bound applications excluding concrete, mortar and grout. Draft prEN 13055-2.Working document revised October 1999.

Nordtest Method NT-Build 485 "Aggregates: Frost resistance test using 1% NaCl", approved1998-11 (UDC: 666.97,691.3; Proj.1214-95; ISSN0283-7153)

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8 NOMENCLATURELWA Lightweight aggregateLWAC Lightweight aggregate concreteNWA Normal weight aggregateNWC Normal weight concretew/b water binder ratiow/c water cement ratio

CEB Comit Euro-international du BtonCEN Comit Europen de Normalisation

CTR Cost Time Resources (form)ELC EuroLightConEN European StandardFIB Fderation Internationale du BtonFIP Fderation Internationale de la PrcontrainteTC Technical Committee (CEN)

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