Aggregates are one of the essential materials used in the construction industry; they are usually regarded as a type of inert filling material within a concrete mixture which is wrong. The characteristics and performance of concrete mixture surely change according to different gradation, maximum size, unit weight, moisture content, hardness, harmful chemicals content, and chemical composition of the aggregates.
Moreover, Aggregates are usually obtained from a wide variety of sources with various characteristics, and are have several different uses.
Accordingly, evaluation of aggregates by testing is very crucial for three main reasons; first, the impact of the aggregates physical and chemical characteristics on concrete; second, the variation and lack of consistency of the aggregates sources; and third, the difference in the intended use. TQP evaluation of aggregates will provide helpful information with respect to:
- • Assessment of new suppliers or sources within the same supplier.
- • Prediction of the aggregate behavior while in use.
- • Comparison between sources.
- • Checking compliance with the project specification or the national or international standard specifications.
- • Checking the consistency of the same source through quality control.
Aggregates Testing
| Aggregates | Test Method | Description |
|---|---|---|
| Aggregate crushing value | BS 812 P110 | This test describes a method for the determination of the aggregate crushing value(ACV) which gives a relative measure of the resistance of an aggregate to crushing under a gradually applied compressive load. |
| Aggregate impact value | BS 812 P112 | This test describes methods for the determination of the aggregate impact value (AIV) which gives a relative measure of the resistance of an aggregate to sudden shock or impact. |
| Clay lumps & friable particles | ASTM C142 | This test method covers the approximate determination of clay lumps and friable particles in aggregates. This test method is of primary significance in determining the acceptability of aggregate with respect to the requirements of Specification C 33. |
| Combined grading analysis | ASTM C33 | This test is to analyze the grading results for the aggregates tested as per ASTM C136 and combined with different ratios to check if it fits with the concrete aggregate requirements. |
| Dry unit weight of aggregate | ASTM C29 | This test method covers the determination of bulk density (“unit weight”) of aggregate in a compacted or loose condition, and calculated voids between particles in fine, coarse, or mixed aggregates. This test method is applicable to aggregates not exceeding125 mm in nominal maximum size. Unit weight is the traditional terminology used to describe the property determined by this test method, which is weight per unit volume(more correctly, mass per unit volume or density). |
| Elongation of aggregate | BS 812-p105.2 | This test describes the method for determining the elongation index of coarse aggregate. Aggregate particles are classified as elongated when they have a length (greatest dimension) of more than 1.8 of their mean sieve size. |
| Flakiness of aggregate | BS 812-p105.1 | This test describes the method for determining the flakiness index of coarse aggregate. Aggregate particles are classified as flaky when they have a thickness (smallest dimension) of less than 0.6 of their mean sieve size. |
| Gradation of "Tout Venant" materials, up to 25 tons | EN 13383 | This test covers the testing of gradation of rock by weighing using calibrated load cell. |
| Light weight pieces in aggregates | ASTM C123 | This test method covers the determination of the percentage of lightweight particles in aggregate by means of sink-float separation in a heavy liquid of suitable specific gravity. This test method is used to determine conformance with provisions of Specification C 33 pertaining to the amount of lightweight material in fine and coarse aggregates. |
| Los Angeles Abrasion (1000cycles) | ASTM C535 | This test method covers testing sizes of coarse aggregate larger than 19 mm for resistance to degradation using the Los Angeles testing machine. |
| Los Angeles Abrasion (500cycles) | ASTM C131 | This test method covers a procedure for testing sizes of coarse aggregate smaller than 37.5 mm for resistance to degradation using the Los Angeles testing machine. |
| Materials finer than 75 micron | ASTM C117 | This test method covers the determination of the amount of material finer than a 75-μm (No. 200) sieve in aggregate by washing. Clay particles and other aggregate particles that are dispersed by the wash water, as well as water-soluble materials, will be removed from the aggregate during the test. |
| Moisture content of aggregates | ASTM C566 | This test method covers the determination of the percentage of evaporable moisture in a sample of aggregate by drying both surface moisture and moisture in the pores of the aggregate. Some aggregate may contain water that is chemically combined with the minerals in the aggregate. Such water is not evaporable and is not included in the percentage determined by this test method. |
| Percentage of fractured particles in coarse aggregate | ASTM D5821 | This test method covers the determination of the percentage, by mass or by count, of a coarse aggregate sample that consists of fractured particles meeting specified requirements. |
| Porosity of Aggregates | ASTM C29 | This test method covers the determination of voids between particles in fine, coarse, or mixed aggregates. This test method is applicable to aggregates not exceeding 125 mm in nominal maximum size. |
| Potential alkali reactivity of aggregates (Rock-Cylinder Method) | ASTM C586 | This test method covers the determination of the expansion of a specimen of carbonate rock while immersed in a solution of sodium hydroxide (NaOH) at room temperature. This test method is intended to give a relatively rapid indication of the potential expansive reactivity of certain carbonate rocks that may be used as concrete aggregates. |
| Resistance of coarse aggregate to degradation by abrasion in the micro-Deval apparatus | ASTM D 6928 | This test method covers a procedure for testing coarse aggregate for resistance to abrasion using the Micro-Deval apparatus. The Micro-Deval abrasion test is a test of coarse aggregate to determine abrasion loss in the presence of water and an abrasive charge. Many aggregates are more susceptible to abrasion when wet than dry, and the use of water in this test incorporates this reduction in resistance to degradation in contrast to some other tests, which are conducted on dry aggregate. The test results are helpful in evaluating the toughness/abrasion resistance of coarse aggregate subject to abrasion. |
| Resistance of fine aggregate to degradation by abrasion in the micro-Deval apparatus | ASTM D 7428 | This test method covers a procedure for testing fine aggregate for resistance to abrasion using the Micro-Deval apparatus. The Micro-Deval abrasion test is a test of fine aggregate to determine abrasion loss in the presence of water and an abrasive charge. Many aggregates are more susceptible to abrasion when wet than dry and the use of water in this testing corporates this reduction in resistance to degradation. The test results are helpful in evaluating the toughness/abrasion resistance of fine aggregate subject to abrasion |
| Resistance of fine aggregate to degradation by abrasion in the micro-Deval apparatus | ASTM D 7428 | This test method covers a procedure for testing fine aggregate for resistance to abrasion using the Micro-Deval apparatus. The Micro-Deval abrasion test is a test of fine aggregate to determine abrasion loss in the presence of water and an abrasive charge. Many aggregates are more susceptible to abrasion when wet than dry and the use of water in this testing corporates this reduction in resistance to degradation. The test results are helpful in evaluating the toughness/abrasion resistance of fine aggregate subject to abrasion |
| Sand equivalent | ASTM D2419 | This test method is intended to serve as a rapid field correlation test. The purpose of this test method is to indicate, under standard conditions, the relative proportions of clay-like or plastic fines and dust in granular soils and fine aggregates that pass the 4.75-mm (No. 4) sieve. |
| Shell content | BS EN 933-7 | Determination of shell content - Percentage of shells in coarse aggregate. |
| Sieve analysis of aggregates | ASTM C136-C117 | This test method covers the determination of the particle size distribution of fine and coarse aggregates by sieving. The results are used to determine compliance of the particle size distribution with applicable specification requirements and to provide necessary data for control of the production of various aggregate products and mixtures containing aggregates. |
| Specific gravity of aggregates | ASTM C127 | This test method covers the determination of the average density of a quantity of coarse aggregate particles (not including the volume of voids between the particles), the relative density (specific gravity)of coarse aggregate. |
| Specific gravity of fine aggregates | ASTM C128 | This test method covers the determination of the average density of a quantity of fine aggregate particles (not including the volume of voids between the particles), the relative density (specific gravity) of fine aggregate. |
| Ten percent fines value (TFV) | BS 812 P111 | This test is for the determination of the ten per cent fines value (TFV)of aggregates which give a relative measure of the resistance of an aggregate to crushing under a gradually applied compressive load. |
| Water absorption by capillary | UKCSA-Technical Manual for Cast Stone | When sampled and tested in accordance with UKCSA-Appendix 2 with an immersion time of 10 minutes, the mean coefficient of water absorption due to capillary action of the three samples shall not exceed 1.0 mg/mm2 with no individual value exceeding 1.3 mg/mm2. |
| Water absorption of coarse aggregates | ASTM C127 | This test method covers the determination the absorption of the coarse aggregateafter soaking in water for a prescribed duration. |
| Water absorption of fine aggregates | ASTM C128 | This test method covers the determination of the absorption of the fine aggregate after soaking in water for a prescribed duration. |
| Wet sieve analysis of aggregates | ASTM C136-C117 | This test method covers the determination of the amount of material finer than a 75-μm (No. 200) sieve in aggregate by washing and the determination of the particle size distribution of fine and coarse aggregates by sieving. |
| Acid soluble chloride in aggregates | BS 1744 P5 | This test covers the determination of acid soluble chloride in coarse and fine aggregates. Aggregates with chloride content higher than the specified values shall not be used in concrete. |
| Acid soluble material in Fine aggregates | BS 812 P119 | This method covers the determination of the amount of acid-soluble material in both of the size fractions of fine aggregates, all passing a 5mm test sieve, separated by sieving on a 0.600 mm test sieve. |
| Acid soluble sulfate in aggregates | BS 1744 P1 | This test covers the determination of acid soluble sulfate in coarse and fine aggregates. Aggregates with sulfate content higher than the specified values shall not be used in concrete. |
| Calcium carbonate content of aggregates | BS 1377-3 | This method describes two tests for the determination of the carbonate content. Both tests depend upon the reaction between carbonates and hydrochloric acid, which liberates carbon dioxide. The first is a rapid titration method .The second uses the gravimetric method described for hardened concrete in BS 1881-124. |
| Methylene blue absorption-Soundness | ASTM C837 | This test method covers the measurement of the adsorption of methylene blue dye by the clay present on the aggregate sample, which is calculated as a methylene blue index for clay. |
| Organic impurities in fine aggregates | ASTM C40 | This test method allows checking the presence of injurious organic impurities in fine aggregates that are to be used in hydraulic cement mortar or concrete. |
| Potential alkali silica reactivity | ASTM C289 | This test method covers chemical determination of the potential reactivity of an aggregate with alkalis in Portland-cement concrete as indicated by the amount of reaction during 24 h at 80oc between 1 N sodium hydroxide solution and aggregate that has been crushed and sieved to pass a 300-µm sieve and be retained on a 150-µm sieve. |
| Silica content of aggregates | ASTM C289 | This test covers the determination of the reactive silica content of coarse and fine aggregates by exposing the sample to boiling with high alkali solution. |
| Soundness of aggregates by Magnesium Sulfate | ASTM C88 | This test method covers the testing of aggregates to estimate their soundness when subjected to weathering action in concrete or other applications. This is accomplished by repeated immersion in saturated solutions of sodium or magnesium sulfate followed by oven drying to partially or completely dehydrate the salt precipitated in permeable pore spaces. The internal expansive force, derived from the rehydration of the salt upon re-immersion, simulates the expansion of water on freezing. This test method furnishes information helpful in judging the soundness of aggregates when adequate information is not available from service records of the material exposed to actual weathering conditions. |
| Soundness of aggregates by Sodium Sulfate | ASTM C88 | This test method covers the testing of aggregates to estimate their soundness when subjected to weathering action in concrete or other applications. This is accomplished by repeated immersion in saturated solutions of sodium or magnesium sulfate followed by oven drying to partially or completely dehydrate the salt precipitated in permeable pore spaces. The internal expansive force, derived from the rehydration of the salt upon re-immersion, simulates the expansion of water on freezing. This test method furnishes information helpful in judging the soundness of aggregates when adequate information is not available from service records of the material exposed to actual weathering conditions. |
| Water soluble chloride in aggregates | BS 1744 - Part 1 | This test covers the determination of water soluble chloride in coarse and fine aggregates. Aggregates with chloride content higher than the specified values shall not be used in concrete. |
| Water soluble sulfate in aggregates | BS 1744 - Part 1 | This test covers the determination of water soluble sulfate in coarse and fine aggregates. Aggregates with sulfate content higher than the specified values shall not be used in concrete. |
