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1 Aggregates 42 Sampling and Preparation 42 Particle Size and Shape 42 Determination of Flakiness and Elongation 42 Density, Voids and Blking 42 Sondness and Chemical Tests 42 Mechanical Properties Aggregates comprise a significant proportion of all materials sed in the many different constrction processes, so it is important to determine the properties of different types of aggregates throgh effective testing and measrement. The reqired properties will vary from project to project, for example, resistance to polishing will be nimportant in a pavement base corse bt will be crcial in a wearing corse. However, the key criteria throghot are accrate and repeatable test procedres, and or range of aggregates testing eqipment has therefore been designed to help yo determine a wide range of factors. These inclde: particle size, shape and textre; relative, blk and compacted densities; sondness and resistance to chemical attack; and mechanical properties. 103

2 42 Aggregates - Sampling and Preparation of Aggregates Sampling and Preparation of Aggregates Sampling and preparation of aggregates and fillers is necessary for a variety of reasons inclding research, design and qality control. The main aim of sampling is to obtain a sample representative of the average qality. Sampling techniqes and procedres are described in varios Standards inclding BS 812:Part 101 and 102 and ASTM D75. Individal items of eqipment necessary for sampling and preparation are described in the Soils Section of the cataloge. Drying and Weighing EN Most test techniqes involve the se of drying ovens and balances. A comprehensive range of eqipment is described in the Laboratory Eqipment Section of the cataloge. Moistre Content The moistre content of aggregate is of importance e.g. when batching concrete or when compacting nbond materials to achieve a specified density. Accrate means of determining moistre content are specified in varios Standards and inclde methods sitable for se in the laboratory or on the constrction site. Individal items of eqipment necessary for determining moistre content are described in the Soils Section and the Laboratory Eqipment Section of the cataloge. Particle Size and Shape Among many of the applications to which aggregate lends itself is its se in economical concrete mixes, impervios, drable asphalts, macadams and road bases. Particle size, shape and textre can have considerable effects on varios design properties and are generally specified within certain limits. Ronded aggregate can lead to instability in a bitminos mixtre yet be ideal as a concrete aggregate where good workability of the mix is essential for placing and compaction. Determination of Particle Size EN933-1, BS 812; ASTM C136 A comprehensive range of sieves, sieve shakers and ancillary eqipment will be fond in the Laboratory Eqipment Section of the cataloge. The range of sieves offered incldes ISO 3310, BS 410 and ASTM E11 mesh sizes and frames. Determination of Sand Eqivalent Vale ASTM D2419; AASHTO T176 The test is sed to determine the relative proportions of clay-like or plastic fines and dsts in aggregate sed for constrction prposes. For Sand Eqivalent Apparats see Section 24. Sample Redction Riffling or qartering are the two methods most often sed to redce a blk sample to a representative size sitable for testing. Flatten the main sample A Riffling, normally sed for redcing material which is in a srface dry condition. B Qartering can be sed to redce damp material down to a qantity which can be frther prepared, e.g. by drying and then riffling. Description of Aggregates Shape Ronded- Water worn or shaped by attrition Irreglar- Natrally irreglar or partly shaped Anglar- Well-defined Flaky- Thickness is small relative to other two dimensions Elongated- Length is larger relative to other two dimensions Divide into qarters Textre Discard two opposite qarters Remix remainder and qarter again Contine process ntil a sample of the reqired size is obtained Glassy Conchoidal fractre Smooth Water worn or smooth de to fractre Granlar Uniform ronded grains Rogh Thickness is small relative to other two dimensions Crystalline Easily visible grains Honeycombed Visible pores and cavities 104 Tel: +44 (0) Fax: +44 (0) ele@eleint.co.k

3 42 Aggregates - Determination of Flakiness and Elongation Determination of Flakiness and Elongation Aggregates which are flaky and/or elongated will often lower the workability of a concrete mix and may also affect long term drability. In bitminos mixtres flaky aggregate makes for a harsh mix and may also crack and break p dring compaction by rolling. Flakiness Sieves and Gages BS 812 EL Flakiness Gage constrcted of heavy gage sheet steel to the dimensions specified in BS 812. Weight 60 g. EL Set of Flakiness Sieves comprising 1 each, 4.9 mm, 7.2 mm, 10.2 mm, 14.4 mm,19.7 mm, 26.3 mm and 33.9 mm. Grid Sieves EN A series of grid sieves formed from 5 mm diameter steel parallel bars secrely fixed in a metal frame. Model Nmber Slot Width Passing Size Retained Size EL mm 80 mm 63 mm EL mm 63 mm 50 mm EL mm 50 mm 40 mm EL mm 40 mm 31.5 mm EL mm 31.5 mm 25 mm EL mm 25 mm 20 mm EL mm 20 mm 16 mm EL mm 16 mm 12.5 mm EL mm 12.5 mm 10 mm EL mm 10 mm 8 mm EL mm 8 mm 6.3 mm EL mm 6.3 mm 5 mm EL mm 5 mm 4 mm Elongation Index BS 812 This method classifies aggregate elongation by measring the length of individal particles. The test is not applicable to material retained on a 63.0 mm BS test sieve. EL Length Gage manfactred to the dimensions specified in BS 812. Weight 700 g. Determination of the Shape Index This method described in EN933-4 measres the ratio of length to width of individal aggregate particles sing a vernier calliper and a specially designed 3:1 length gage. EL Set of Flakiness Sieves EL :1 Shape Index Calliper. Weight 1 kg. Vernier Calliper see Laboratory Eqipment Section. EL Length Gage EL42-03 series Grid Sieve 105

4 42 Aggregates - Density, Voids and Blking Density, Voids and Blking As with any poros material, the vale obtained for the particle density of an aggregate will depend on the method of test and apparats sed. Different particle sizes within a sample often have different particle densities. The term particle density expressed in Mg/ m 3 is nmerically eqal to the specific gravity. Varios methods, depending pon the type and size of material to be tested, are specified in Standards for testing aggregate. Particle Density (specific gravity) and Water Absorption EN , , BS 812; ASTM C127; AASHTO T85 Method for aggregate between 63 mm and 5 mm. EL /01 Boyancy Balance g x 0.1 g spplied with frame, water tank and sspension hook. For V AC, Hz, 1 ph. Accessory EL Wire Basket with handle for BS 812 Relative Density. 200 mm diameter x 190 mm deep, 1.70 mm wire mesh. Particle Density (specific gravity) and Water Absorption BS 812; ASTM C128; AASHTO T84 Method for aggregate 20 mm and smaller The gas jar method described in BS 812 is sitable for all aggregates smaller than 20 mm in size and is particlarly sited to friable aggregates. The pyknometer method described in ASTM C128 is sitable for determining the particle density of samples of fine aggregates. The particle density of fillers can be determined sing the density bottle method specified for testing cement. EL Sand Absorption Cone made of brass to the dimensions given in BS 812, ASTM C128 and AASHTO T84. Weight 250 g. EL Tamping Rod for se with cone. Tamping face is 25 mm diameter and complies with BS 812, ASTM C128 and AASHTO T84. Weight 400 g. Blk Density Measres Manfactred from heavy gage steel these blk density measres comply with the reqirements of either BS 812 or ASTM C-29. Other than the 3 litre size, all measres incorporate carrying handles as standard. EL /01 Boyancy Balance EL Set of two measres Capacity 3 litre Standard BS 812; ASTM C29 Boyancy Balance 6000 g EL Set of three measres 7 litre Capacity BS 812 Standard The boyancy balance system developed by ELE consists of a rigid spport frame, incorporating a water tank monted on a platform. 10 litre BS 812-2, 3797, EN , ASTM C138 A mechanical lifting device is sed to raise the water tank throgh the frame height immersing the specimen sspended below the balance. 15 litre 30 litre BS 812; ASTM C138 BS 812; ASTM C138 The balance spplied may also be sed as a standard weighing device, ths providing a versatile and comprehensive weighing system in the laboratory. 106 Tel: +44 (0) Fax: +44 (0) ele@eleint.co.k

5 42 Aggregates - Sondness and Chemical Tests Sondness and Chemical Tests The presence of organic matter and certain chemicals can have a considerable inflence on the strength and drability of concrete. The ability of aggregates to resist excessive change in volme (sondness) de to physical changes in the environment is also of importance. Knowledge of these potentially harmfl factors will ensre that precations can be taken at the mix design stage of a project. Chloride Content: Rapid method Qantab chloride titrators can be sed for estimating the chloride content of aqeos soltions. They are sitable for site testing and qality control of aggregates reqiring less than 30 mintes to obtain a reslt. EL Qantab Chloride Titrator Strips. Type 1175 titration range 0.005% to 0.1% (30 to 600 ppm) NaCl. Pack of 50. Weight 10 g. EL Qantab Chloride Titrator Strips. Type 1176 titration range 0.05% to 1% (300 to 6000 ppm) NaCl. Pack of 40. Weight 10 g. Slphate Content: Rapid method A qalitative or semi-qantitative test is recommended for determining slphate ions in aqeos soltions. Slphate test strips are convenient measring devices for preliminary assessment of slphate content. EL Slphate Test Strips. Detection range 200 to 900 mg/l. Pack of 100. Weight 10 g Sondness of Aggregates BS 812; ASTM C88; AASHTO T104; EN The sondness of aggregates to physical changes cased by the environment is important to the long-term drability characteristics of concrete. Excessive changes in volme can be cased by freezing and thawing, thermal changes at temperatres greater than freezing, and cycles of wetting and drying. Hydrometers and Wire Baskets see Laboratory Eqipment Section. Organic Imprities in Fine Aggregate ASTM C40 If aggregate contains organic imprities it may not be sitable for inclsion in concrete. Organic imprities, sally tannic acid and its derivatives, may interfere with the chemical reactions of hydration. Imprities are more likely to be fond in fine (sand) aggregate. EL Glass Bottle. 12 once (300 ml approx) capacity, gradated at 2, 4 and 7 once positions. Complete with screw cap. Weight 340 g. EL Color Standard with five organic color transparencies monted in a holder. EL Qantab Chloride Titrator Strips Special Note: Sodim Hydroxide pellets are reqired bt not spplied by ELE. EL Color Standard 107

6 42 Aggregates - Mechanical Properties Mechanical Properties The diverse range of aggregates available to the engineer makes it essential to select a material that is adeqate for a given application. The following eqipment is designed to determine varios mechanical characteristics that need to be known in order to select the most sitable and economic type of aggregate. Aggregate Impact Vale (AIV) BS The apparats has been designed in a particlarly heavy dty form, with specially hardened steel srfaces for minimm wear. The assembly is heavily plated to ensre corrosion resistance and forms a rigid frame arond the qick-release trigger mechanism which ensres an effective free fall of the hammer when released. A bilt-in conter atomatically indicates the nmber of blows delivered. The apparats is spplied complete with cylindrical measre 75 mm diameter x 50 mm deep, and a steel tamping rod 16 mm diameter x 600 mm long. EL Aggregate Impact Vale Apparats Aggregate Crshing Vale (ACV) and Ten Percent Fines Vale (TFV) BS , 111 These tests are a measre of the crshing properties of aggregate and se the same basic eqipment. The ACV test reqires a standard load of 400 kn to be applied over a period of 10 mintes while the TFV test measres the force reqired to prodce a specified depth of plnger penetration. ACV/TFV Standard Test EL Aggregate Crshing Vale Apparats comprising 150 mm nominal diameter steel cylinder, plnger and base plate spplied complete with metal measre and tamping rod. Weight 16.6 kg. Spare Tamping Rod see EL ACV/TFV Test for Aggregate Smaller than 10 mm EL Aggregate Crshing Vale Apparats comprising 75 mm nominal diameter steel cylinder, plnger and base plate spplied complete with metal measre and tamping rod. Weight 3.5 kg. Spare EL Tamping Rod. 8 mm diameter x 300 mm long with ronded end. Weight 350 g. EL Aggregate Impact Vale Apparats EL & EL Aggregate Crshing Vale Apparats 108 Tel: +44 (0) Fax: +44 (0) ele@eleint.co.k

7 42 Aggregates - Mechanical Properties Los Angeles Abrasion Machine EN , ASTM C131, C535 Eropean and ASTM methods Revoltion conter Safety ct-ot Fll width cover The Los Angeles Machine comprises a heavy steel cylinder, rotated abot its horizontal axis. The cylinder incorporates a removable internal shelf, as specified in the ASTM and EN test methods. The ELE Los Angeles Machine s heavy dty steel cylinder is manfactred from strctral steel plate conforming to S275 of EN 10025:1993. EL /01 Los Angeles Abrasion Machine The filling apertre is provided with a cover and a safety stop btton is prominently positioned. The machine is fitted with a revoltion conter and steel tray for specimen nloading. Spplied withot abrasive charges which shold be ordered separately. EL /01 Los Angeles Abrasion Machine. Less charges. For V AC, 50 Hz, 1ph. EL /01 Los Angeles Abrasion Machine with CE Safety Cabinet. Fitted with microswitches. Less charges. For V AC, 50 Hz, 1 ph. Accessories EL /10 Set of Abrasive Charges (ASTM) EL /10 Set of Abrasive Charges (EN) EL /01 Los Angeles Abrasion Machine with CE Safety Cabinet 109