42 Aggregates Sampling and preparation of aggregates Sampling and Preparation of Aggregates Particle Size and Shape Sampling and preparation of aggregates and fillers is necessary for a variety of reasons including research, design and quality control.The main aim of sampling is to obtain a sample representative of the average quality. Sampling techniques and procedures are described in various standards including BS 812:Part 101 and 102 and ASTM D75. Individual items of equipment necessary for sampling and preparation are described in the Soils Section of the catalogue. Amongst many of the applications to which aggregate lends itself is its use in economical concrete mixes, impervious, durable asphalts, macadams and road bases. Particle size, shape and texture can have considerable effects on various design properties and are generally specified within certain limits. Rounded aggregate can lead to instability in a bituminous mixture yet be ideal as a concrete aggregate where good workability of the mix is essential for placing and compaction. Drying and Weighing EN 932-2 Determination of Particle Size Most test techniques involve the use of drying ovens and balances. A comprehensive range of equipment is described in the Laboratory Equipment section of the catalogue. Moisture Content The moisture content of aggregate is of importance e.g. when batching concrete or when compacting unbound materials to achieve a specified density. Accurate means of determining moisture content are specified in various standards and include methods suitable for use in the laboratory or on the construction site. Individual items of equipment necessary for determining moisture content are described in the Soils Section and the Laboratory Equipment Section of the catalogue. BS 812; ASTM C136; EN933-1 A comprehensive range of sieves, sieve shakers and ancillary equipment will be found in the Laboratory Equipment section of the catalogue.The range of sieves offered includes ISO 3310, BS 410 and ASTM D11 mesh sizes and frames. Determination of Sand Equivalent Value ASTM D2419; AASHTO T176; EN 933-8 The test is used to determine the relative proportions of clay-like or plastic fines and dusts in aggregate used for construction purposes. For Sand Equivalent Apparatus see Section 24 Description of Aggregates Sample Reduction Riffling or quartering are the two methods most often used to reduce a bulk sample to a representative size suitable for testing. A Riffling, normally used for reducing Shape Rounded Water worn or shaped by attrition material which is in a surface dry condition. B Quartering can be used to reduce damp material down to a quantity which can be further prepared, e.g. by drying and then riffling. Flatten the main sample Irregular Naturally irregular or partly shaped Angular Well-defined Flaky Thickness is small relative to other two dimensions Elongated Length is larger relative to other two dimensions Divide into quarters Remix remainder and quarter again 120 Discard two opposite quarters Continue process until a sample of the required size is obtained Texture Glassy Conchoidal fracture Smooth Water worn or smooth due to fracture Granular Uniform rounded grains Rough Rough fracture, no easily visible crystalline grains Crystalline Easily visible grains Honeycombed Visible pores and cavities Aggregates Determination of flakiness and elongation 42 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 durability. In bituminous mixtures flaky aggregate makes for a harsh mix and may also crack and break up during compaction by rolling. Ordering Information EL42-0410 Flakiness Gauge constructed of heavy gauge sheet steel to the dimensions specified in BS 812. Weight 60 g Flakiness Sieves and Gauges BS 812 BS 812 Flakiness Sieves Model number Slot dimensions width length Passing size Retained size Elongation Index EL42-0670 EL42-0680 El42-0700 EL42-0710 EL42-0720 EL42-0730 EL42-0740 4.9 mm 7.2 mm 10.2 mm 14.4 mm 19.7 mm 26.3 mm 33.9 mm 30 mm 40 mm 50 mm 60 mm 80 mm 90 mm 100 mm 10.0 14.0 20.0 28.0 37.5 50.0 63.0 BS 812 mm mm mm mm mm mm mm 6.3 mm 10.0 mm 14.0 mm 20.0 mm 28.0 mm 37.5 mm 50.0 mm This method classifies aggregate elongation by measuring the length of individual particles.The test is not applicable to material retained on a 63.0 mm BS test sieve. Ordering Information EL42-0820 Length Gauge manufactured to the dimensions specified in BS 812. Weight 700 g Grid Sieves EN 933-3 A series of grid sieves formed from 5 mm diameter steel parallel bars securely fixed in a metal frame. Model number EL42-0326 EL42-0324 EL42-0322 EL42-0320 EL42-0318 EL42-0316 EL42-0314 EL42-0310 EL42-0308 EL42-0306 EL42-0304 EL42-0302 EL42-0300 Slot width 40 mm 31.5 mm 25 mm 20 mm 16 mm 12.5 mm 10 mm 8 mm 6.3 mm 5.0 mm 4.0 mm 3.15 mm 2.5 mm Passing size 80 mm 63 mm 50 mm 40 mm 31.5 mm 25 mm 20 mm 16 mm 12.5 mm 10 mm 8 mm 6.3 mm 5 mm Retained size 63 mm 50 mm 40 mm 31.5 mm 25 mm 20 mm 16 mm 12.5 mm 10 mm 8 mm 6.3 mm 5 mm 4 mm EL42-0820 Length Gauge Determination of the Shape Index This method described in EN933-4 measures the ratio of length to width of individual aggregate particles using a vernier calliper and a specially designed 3:1 length gauge. Ordering Information EL42-0821 3:1 Shape Index Calliper. Weight 1 kg Vernier Calliper EN933-3 Grid Sieves see Laboratory Equipment Section EL42-0821 3:1 Shape Index Calliper, EL42-0820 Length Gauge 121 42 Aggregates Density, voids and bulking Density, Voids and Bulking As with any porous material, the value obtained for the particle density of an aggregate will depend on the method of test and apparatus used. Different particle sizes within a sample often have different particle densities.The term particle density expressed in Mg/m3 is numerically equal to the specific gravity. Various methods, depending upon the type and size of material to be tested, are specified in standards for testing aggregate. Particle Density (specific gravity) and Water Absorption BS 812; ASTM C127; AASHTO T85; EN 1097-6, 12697-6 Method for aggregate between 63 mm and 5 mm EL42-1700 Sand Absorption Cone with EL42-1720 Tamping Rod 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 suitable for all aggregates smaller than 20 mm in size and is particularly suited to friable aggregates.The pyknometer method described in ASTM C128 is suitable for determining the particle density of samples of fine aggregates.The particle density of fillers can be determined using the density bottle method specified for testing cement. Ordering Information EL42-1000/01 Buoyancy Balance with Accessory Buoyancy Balance 6000 g The buoyancy balance system developed by ELE consists of a rigid support frame, incorporating a water tank mounted on a platform. A mechanical lifting device is used to raise the water tank through the frame height immersing the specimen suspended below the balance. EL42-1700 Sand Absorption Cone made of brass to the dimensions given in BS 812, ASTM C128 and AASHTO T84. Weight 250 g EL42-1720 Tamping Rod for use with cone.Tamping face is 25 mm diameter and complies with BS 812, ASTM C128 and AASHTO T84. Weight 400 g Accessory EL42-1240 Absorbent Cloths, pack of 3. The balance supplied may also be used as a standard weighing device, thus providing a versatile and comprehensive weighing system in the laboratory. Bulk Density Measures Ordering Information Manufactured from heavy gauge steel these bulk density measures comply with the requirements of either BS 812 or ASTM C-29. Other than the 3 litre size all measures incorporate carrying handles as standard. EL42-1000/01 Bouyancy Balance, 6000 g x 0.1 g supplied with frame, water tank and suspension hook. For 220 – 240 V AC, 50 – 60 Hz, 1 ph. Accessory EL42-1005 122 Wire Basket with handle for BS 812 Relative Density. 200 mm diameter x 190 mm deep, 1.70 mm wire mesh. Catalogue no. Capacity Standard EL42-1995 EL42-2000 EL34-2830 3 litre 7 litre 10 litre EL34-2820 EL34-2800 15 litre 30 litre BS 812; ASTM C29 BS 812 BS 812-2, 3797, EN 1097-3 12350-6, ASTM C138 BS 812; ASTM C138 BS 812; ASTM C138 Aggregates Soundness and chemical tests Soundness and Chemical Tests 42 Shrinkage of Aggregate BS812-120, EN 1367-4 The presence of organic matter and certain chemicals can have a considerable influence on the strength and durability of concrete.The ability of aggregates to resist excessive change in volume (soundness) due to physical changes in the environment is also of importance. Knowledge of these potentially harmful factors will ensure that precautions can be taken at the mix design stage of a project. The volume of an aggregate which is susceptible to drying shrinkage may change by as much as four times when moving from the wet to dry state.The test method described uses prisms of known dimensions made from aggregate up to a maximum size of 20 mm. Chloride Content: Rapid method EL42-2970 Three gang Prism Mould for specimens 50 x 50 x 200 mm. Weight 8 kg Quantab chloride titrators can be used for estimating the chloride content of aqueous solutions.They are suitable for site testing and quality control of aggregates requiring less than 30 minutes to obtain a result. Ordering Information Ordering Information Steel Inserts Measuring Apparatus Standard Length Rod see EL34-8541 see EL34-8500 see EL34-8509 EL42-2970 Three-gang Prism Mould with Accessories EL42-2950 Quantab Chloride Titrator Strips.Type 1175 titration range 0.005% to 0.1% (30 to 600 ppm) NaCl. Pack of 50. Weight 10 g EL42-2952 Quantab Chloride Titrator Strips.Type 1176 titration range 0.05% to 1% (300 to 6000 ppm) NaCl. Pack of 40. Weight 10 g Organic Impurities in Fine Aggregate ASTM C40 If aggregate contains organic impurities it may not be suitable for inclusion in concrete. Organic impurities, usually tannic acid and its derivatives, may interfere with the chemical reactions of hydration. Impurities are more likely to be found in fine (sand) aggregate. EL42-2950 Quantab Tritrator Strips Sulphate Content: Rapid method A qualitative or semi-quantitative test is recommended for determining sulphate ions in aqueous solutions. Sulphate test strips are convenient measuring devices for preliminary assessment of sulphate content. Ordering Information EL42-2958 Sulphate Test Strips detection range 200 to 900 mg/l. Pack of 100. Weight 10 g Ordering Information EL42-3000 Glass Bottle 12 ounce (300 ml approx) capacity, graduated at 211/42, 411/42 and 7 ounce positions. Complete with screw cap. Weight 340 g EL42-3040 Colour Standard with five organic colour transparencies mounted in a holder. Special Note: Sodium Hydroxide pellets are required but not supplied by ELE EL42-3040 Colour Standard Soundness of Aggregates BS 812; ASTM C88; AASHTO T104; EN 1367-2 The soundness of aggregates to physical changes caused by the environment is important to the long-term durability characteristics of concrete. Excessive changes in volume can be caused by freezing and thawing, thermal changes at temperatures greater than freezing, and cycles of wetting and drying. ASTM C88 specifies a test method to determine the potential soundness or otherwise of aggregates. Hydrometers and Wire Baskets see Laboratory Equipment Section 123 42 Aggregates Mechanical properties Mechanical Properties The diverse range of aggregate available to the engineer makes it essential to select a material that is adequate for a given application.The following equipment is designed to determine various mechanical characteristics that need to be known in order to select the most suitable and economic type of aggregate. Aggregate Impact Value (AIV) BS 812-112 The apparatus has been designed in a particularly heavy duty form, with specially hardened steel surfaces for minimum wear.The assembly is heavily plated to ensure corrosion resistance and forms a rigid frame around the quick-release trigger mechanism which ensures an effective free fall of the hammer when released. A built-in counter automatically indicates the number of blows delivered. The apparatus is supplied complete with cylindrical measure 75 mm diameter x 50 mm deep, and a steel tamping rod 16 mm diameter x 600 mm long. Ordering Information EL42-4000 Aggregate Impact Value Apparatus Weight 52 kg ACV Apparatus with Metal Measures and Tamping Rods Aggregate Crushing Value (ACV) and Ten Percent Fines Value (TFV) BS 812-110, 111 EL42-4000 AIV Apparatus These tests are a measure of the crushing properties of aggregate and use the same basic equipment.The ACV test requires a standard load of 400 kN to be applied over a period of 10 minutes while the TFV test measures the force required to produce a specified depth of plunger penetration. ACV/TFV Standard Test Ordering Information EL42-4300 Aggregate Crushing Value Apparatus comprising 150 mm nominal diameter steel cylinder, plunger and base plate. Weight 16.6 kg EL42-4360 Metal Measure 115 mm diameter x 180 mm deep. Weight 870 g Tamping Rod see EL34-0130 ACV/TFV Test for Aggregate Smaller than 10 mm Ordering Information EL42-4500 Aggregate Crushing Value Apparatus comprising 75 mm nominal diameter steel cylinder, plunger and base plate. Weight 3.5 kg EL42-4560 Metal Measure 57 mm diameter x 90 mm deep. EL42-4580 Tamping Rod 8 mm diameter x 300 mm long with rounded end. Weight 350 g 124 Aggregates Mechanical properties Los Angeles Abrasion Machine ASTM C131, C535; EN 1097-2 ■ ■ ■ ■ European and ASTM methods Revolution counter Safety cut-out Full width cover The Los Angeles Machine comprises a heavy steel cylinder, rotated about its horizontal axis. The cylinder incorporates a removable internal shelf.Two alternative shelf positions are provided, one for ASTM and one for the EN test method. 42 Ordering Information EL42-5305/01 Los Angeles Abrasion Machine as specified For 220 – 240 V AC, 50 Hz, 1 ph EL42-5310/01 Los Angeles Abrasion Machine with CE Safety Cabinet fitted with microswitches. Less charges. For 220 – 240 V AC, 50 Hz, 1 ph Accessories EL42-5300/10 Set of Abrasive Charges (ASTM) EL42-5305/10 Set of Abrasive Charges (EN) The ELE Los Angeles Machine’s heavy duty steel cylinder is manufactured from structural steel plate conforming to S275 of EN 10025:1993 The filling aperture is provided with a cover and a safety stop button is prominently positioned.The machine is fitted with a revolution counter and steel tray for specimen unloading. Supplied without abrasive charges which should be ordered separately. EL42-5310/01 Los Angeles Abrasion Machine with CE safety cabinet EL42-5305/01 Los Angeles Abrasion Machine 125 42 Aggregates Mechanical properties Micro-Deval Apparatus EN 1097-1 ■ ■ ■ ■ Satisfies European test method Machine with safety cover and cutout Positive drive system 4 drums supplied as standard The apparatus comprises a main frame assembly with drive motor and twin roller bearers.Two models are available, EL42-5210/01 features a hinged safety cover with automatic cut-off of power to the drive system when the guard is opened. Model EL42-5205/01 is supplied less safety cover. As standard both units are supplied with a revolution counter and on/off switches. Each model is supplied with 4 stainless steel drums each 200 mm diameter x 154 mm long and 20.0 kg charge (5 kg required for test) of steel balls. A waterproof sealing gasket is fitted to the drum enclosure. Drums locate positively on the roller bearers that are driven at a speed of 100 ±5 rpm. Ordering Information EL42-5205/01 Micro-Deval Apparatus complete with 4 stainless steel drums, 20.0 kg of 10 mm diameter steel ball charges (5 kg required for test). Dimensions 450 x 1000 x 950 mm (l x w x h). Weight 150 kg. For 220 – 240 V, 50 Hz, 1 ph. EL42-5210/01 Micro-Deval Apparatus EL42-5210/01 Micro-Deval Apparatus complete with safety cover, 4 stainless steel drums, 20.0kg of 10 mm diameter steel ball charges (5 kg required for test). Dimensions 650 x 1150 x 1150 mm (l x w x h). Weight 180 kg. For 220 – 240 V, 50 Hz, 1 ph. Accessories EL42-5200/11 Steel Charges 10 mm diameter for Micro-Deval Apparatus (20.2 kg pack) EL42-5200/10 Stainless Steel Drum 200 mm diameter x 154 mm long for Micro-Deval Apparatus. Supplied without steel charges. Weight 25 kg EL42-5205/01 Micro-Deval Apparatus ELE International has a policy of continuous product review to ensure compliance to the relevant testing standards. The latest product information can be found on the ELE e-commerce system at www.ele.com We recommend that you take a few minutes to register for access to this fully integrated and advanced facility for: ■ Placing and tracking orders anytime 24/7 ■ Receiving mailings on special offers and new products ■ Expanded product specifications ■ Downloading available product datasheets 126 Aggregates Mechanical properties 42 Polished Stone Value (PSV) BS 812-114; EN 1097-8 The Polished Stone Value provides a measure of the resistance to polishing under the action of vehicle tyres and is a fundamental test which is often used when selecting aggregate for road surfacing material. Accelerated Polishing Machine BS 812 ■ ■ ■ ■ Satisfies European method High safety standards Sealed long-life bearings Sealed control panel Specimens are manufactured in accurately machined and matched moulds; they are then removed from the moulds and located on the ‘Road Wheel’. Abrasives are continuously fed to the road wheel. Water is introduced at a controlled rate via a variable flow meter and self-contained water supply. Used water and abrasives are collected in a large removable tray. Electrical supply is protected by thermal cutouts and an emergency stop button. Ordering Information EL42-5505/01 Accelerated Polishing Machine complete with 4 moulds and 4 mould plates. Weight 220 kg For 220 – 240 V, 50 Hz, 1 ph Specification Dimensions (l x w x h) Rated power Road wheel Applied load on specimens Feed rates Corn emery: Water: Flour emery: Water: 550 x 630 x 1600 mm (bottle fitted) 400 W 315 to 325 rpm 715 to 735 N 20 to 34 g/min 20 to 34 ml/min 2 to 4 g/min 5 to 8 ml/min EL42-5505 Accelerated Polishing Machine Road Wheel and samples Accessories EL42-5520 Corn Emery ungraded, 3 kg pack. EL42-5525 Flour Emery ungraded, 3 kg pack. Spares Model number Description EL42-5505/12 EL42-5505/20 EL42-5505/21 EL42-5505/22 Tyred Wheel Assembly, dark Tyred Wheel Assembly, light Mould Plate Specimen Mould 127 42 Aggregates Mechanical properties Friction Tester BS 812-114, 8204, 6677-1, 6717, 7263-1, 3, 7932, 7976; EN 1097-8, 1341, 1342, 1338, 1344, 13036-4, 14231; DD ENV 12633, ASTM E303 This apparatus consists of a spring-loaded rubber slider mounted on a pendulum arm.The arm can be adjusted vertically from a rigid support column when in operation.The base has three adjustable feet so that the swing of the pendulum during test moves through a truly circular path while operating directly on a road surface. All bearings and working parts are enclosed where possible to protect them against wear and contamination. As standard, the Tester incorporates the 'F scale' that is necessary for laboratory testing. The optional accessory Baseplate is required for laboratory tests. Ordering Information EL42-6000 Friction Tester. Weight 31 kg Accessories EL42-6200 Baseplate with specimen mounting block for use with machine in a laboratory. Weight 8 kg Spares EL42-6221 Replacement Mounted Rubber Slider for laboratory use. Weight 20 g EL42-6222 Replacement Mounted Rubber Slider for road version of machine. Weight 35 g EL42-6000 Friction Tester 128 Friction Tester in carrying case