Aggregate Tests
Laboratory tests on coarse and fine aggregate: gradation, specific gravity, particle shape and angularity, toughness, soundness and cleanliness.
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Sulfate Soundness Test
The soundness test determines an aggregate’s resistance to disintegration by weathering and, in particular, freeze-thaw cycles.
Fine Aggregate Specific Gravity
The fine aggregate specific gravity test (Figure 1) is used to calculate the specific gravity of a fine aggregate sample by determining the ratio of the weight of a given volume of aggregate to the weight of an equal volume of water.
Gradation Test
The gradation and size test (Figure 1) is used to determine aggregate particle size distribution. Size distribution is perhaps the single most important aggregate quality associated with the control of HMA mixtures.
Fineness Modulus
For aggregates used in PCC, another common gradation description for fine aggregate is the fineness modulus. It is described in ASTM C 125 and is a single number used to describe a gradation curve. It is defined as:
Particle Index
The particle index test provides a combined shape-texture characterization. This test requires that an aggregate sample be divided up into specific size fraction. Each size fraction is placed into a container in three layers.
Fine Aggregate Angularity
The fine aggregate angularity (FAA) test (Figure 1) is an indirect method of assessing the angularity of fine aggregate.
Flat and Elongated Particles
The flat and elongated particle test is used to determine the dimensional ratios for aggregate particles of specific sieve sizes.
Percent Fractured Face Test
A sample retained on the 4.75 mm (No. 4) sieve is collected and the number of particles with fractured faces is compared to the number of particles without fractured faces.
Los Angeles Abrasion
The Los Angeles (L.A.) abrasion test (Figure 1) is a common test method used to indicate aggregate toughness and abrasion characteristics.
Sand Equivalent
The sand equivalent test (Figure 1) is a rapid field test to show the relative proportions of fine dust or clay-like materials in fine aggregate (or granular soils).
Coarse Aggregate Angularity
The coarse aggregate angularity (CAA) test is a method of determining the angularity of coarse aggregate (Figure 1).
Coarse Aggregate Specific Gravity
The coarse aggregate specific gravity test (Figure 1) is used to calculate the specific gravity of a coarse aggregate sample by determining the ratio of the weight of a given volume of aggregate to the weight of an equal volume of water.
Sieve
A sieve is a mechanical device used to separate samples of different sizes.