Aggregate Testing

10% Fine Value:

All aggregates are required to meet a minimum strength valve, as defined by the 10% value test. This and other specifications ensure that only the highest quality materials are being used on construction projects. Test Method: IS: 2386 (P-4)1963

Alkali Aggregate Reactivity:

Alkali-aggregate reaction is the term mainly referred to a reaction which occurs over time in concrete between the highly alkaline cement paste and non-crystalline silicon dioxide, which is found in many common aggregates. This reaction can cause expansion of the altered aggregate, leading to spalling and loss of strength of the concrete.
Test Method: IS: 2386 (P-7) 1963

Clay Slit and Dust passing/ Sieve Analysis:

This test helps in determining the size of a granular material. The size distribution is often of critical importance to the way the material performs in use. A sieve analysis can be performed on any type of non-organic or organic granular material including sand, crushed rock, clay, granite, fled-spars, coal and soil, a wide range of manufactured powders, grain and seeds, down to a minimum size depending on the exact method. Being such a simple technique of particle sizing, it is probably the most commonly used to date.
Test Method: IS: 2386 (P-2) 1963

Crushing Value:

The Aggregate Crushing Value offers a related measure of the resistance of an average to crushing under a compressive load that is gradually applied.
Test Method: IS: 9376-1979, IS: 2386 (P-4)1963

Flakiness and Elongation Index:

Flakey is the term applied to aggregate or chippings that are flat and thin with respect to their length or width. Aggregate particles are said to be flakey when their thickness is less than 0.6 of their mean size. The flakiness index is found by expressing the weight of the flakey aggregate as a percentage of the aggregate tested.
Test Method: IS: 2386 (P-1) 1963

Impact Value:

This test helps in determining the value which indicates the ability of an aggregate to resist crushing. The lower the figure the stronger the aggregate, i.e. the greater its ability to resist crushing.
Test Method: IS: 2386 (P-4) 1963, ASTMC 131-2006

Soundness:

This test helps in determining the resistance to disintegration by freezing and thawing. It furnishes information helpful in judging the soundness of aggregates subjected to weathering, particularly when adequate information is not available from service records of the behaviour of the aggregate.
Test Method: IS: 2386 (P-5)1963

Specific gravity and water absorption:

The specific gravity of an aggregate is considered to be a measure of strength or quality of the material. The specific gravity test helps in the identification of stone. Water absorption gives an idea of the strength of aggregate. Aggregates having more water absorption are more porous in nature and are generally considered unsuitable unless they are found to be acceptable based on strength, impact and hardness tests.
Test Method: IS: 2386 (P-3)1963, ASTM C 127, 128-2007

Sulphate Content:

The total sulphate content of aggregate is usually measured to assess whether the aggregates contribution to the total sulphate content of a concrete mix will be low enough to prevent any deleterious effects.
Test Method: IS: 4032-1985

ISO Striping Value:

The ISO striping value is used to determine the resistance of aggregates to stripping of bitumen coating in the presence of water. It helps evaluate the adhesion quality between bitumen and aggregate.
Test Method: IS: 6241-1971

Bulk Density:

Bulk density indicates the mass of aggregate that would fill a container of a specified unit volume. It helps in mix proportioning and understanding compactness and voids in aggregates.
Test Method: IS: 2386 (Part 3) - 1963

Finer than 75 Micron:

This test determines the amount of silt, clay, and other fine particles present in aggregates. Excessive fines can adversely affect the bond strength and durability of concrete or asphalt.
Test Method: IS: 2386 (Part 1) - 1963