Bulk specific gravity gsb the ratio of the mass, in air, of a volume of aggregate including the permeable and impermeable voids in the particles, but not. Aashto t84 c128 specific gravity fine aggregate duration. Coarse aggregate specific gravity pavement interactive. Standard test method for relative density specific gravity. Determining the specific gravities of coarse aggregates. The specific gravity of aggregates normally ranges from about 2. 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. Specific gravity relative density of a blended aggregate the specific gravity of a blended aggregate is not simply the weighted average of the specific gravities of the individual components. More fineness modulus value indicates that the aggregate is coarser and small value of fineness modulus indicates that the aggregate is finer. Bulk specific gravity an overview sciencedirect topics. Specific gravity is defined as the ratio of weight of aggregate to the weight of. Improved test methods for specific gravity and absorption. Relative density specific gravity is also used in the computation of voids in aggregate in test method c29c29m. It is the measure of strength or quality of the specific material.
The specific gravity of an aggregate is considered to be a measure of strength or. North dakota department of transportation, materials and research. The ratio of the weight in air of a unit volume of aggregate at a stated temperature to the weight in air of an equal volume. The specific gravity of aggregates normally used in road construction ranges from about 2. Effect of specific gravity on aggregate varies the weight. Clean the pycnometer, dry it, find the weight of the pycnometer. Some deleterious particles are lighter than the good aggregates.
Mar 24, 2018 specific gravities can vary widely depending upon aggregate type. Fill the remaining part of pycnometer with distilled water and weight w3. For aggregate reduction use the appropriate procedures described in t 248. Improved test methods for specific gravity and absorption of coarse and fine aggregate.
Sep 01, 2014 fineness modulus is generally used to get an idea of how coarse or fine the aggregate is. This approach involves the soaking of the coarse aggregate. Coarse aggregate specific gravity set specific gravity. What are the errors that affected the test results of test specific gravity and absorption of coarse aggregate.
Improved test methods for specific gravity and absorption of. The coarse aggregate specific gravity test figure 1 is used to calculate the. The determinations that may be made from this procedure are identical to those made in aashto t 85 specific gravity and absorption of coarse aggregate. Nov 05, 2018 what are the errors that affected the test results of test specific gravity and absorption of coarse aggregate. What are the errors that affected the test results of test. This approach involves the soaking of the coarse aggregate samples for 15h aashto t 85 and 24 4 h astm c127, and drying the aggregate to its saturatedsurface dry ssd state with the aid of a dry absorbent cloth. A balance of capacity not less than 3kg,readable and accurate to 0. Void contents range from 30% to 45% for coarse aggregate to about 40% to 50% for fine aggregates. To derive an appropriate equation, lets assume a blend of two aggregates a and b. Effect of specific gravity on aggregate varies the weight of.
This test method determines the specific gravity of fine aggregates that have been soaked for a period of 1519 hrs. Whereas, bulk specific gravity bsg is a measure of the weightvolume of solids and pores of a material. Specific gravities of our samples came out to be 2. Water absorption value of our sample comes out to be 0. Determination of specific gravity of fine aggregates. Specific gravity and absorption capacity of the coarse aggregate. The current method of specific gravity and absorption of coarse aggregate testing is based on the aashto t 85 and astm c127 standards. Standard test method for relative density specific. Chapter 5 practical significance of aggregate specific gravity test results. The specific gravity may be expressed as bulk specific gravity, bulk specific gravity ssd or apparent specific gravity.
Specific gravity of coarse and fine aggregates civilarc. The specific gravity of sands is considered to be around 2. Relative density can be calculated by simply multiplying the specific gravity of the coarse aggregate, whose typical range is 2. Procedure for the determination of specific gravity of fine aggregate. Sfn 2199 72019 pit location laboratory number owner project number sampled from pcn type of material submitted by date received. Specific gravity of aggregates is considered as an indication of strength. This test method covers the determination of specific gravity and absorption of coarse aggregate. Bulk specific gravity gsb also known as bulk dry specific gravity the ratio of the weight in air of a unit volume of aggregate at a stated temperature to the weight in air of an equal volume of gasfree distilled water at a stated temperature figure 2. Specific gravity of major aggregates falls within the range of 2. The increase in mass due to water in the pores of the material. Fineness modulus is an empirical factor obtained by adding the cumulative percentages of aggregate retained on each of the standard sieves ranging from 80 mm to 150 micron and dividing this sum by 100. When corresponding fine aggregate specific gravity and absorption are determined on minus no.
Oct 08, 2015 specific gravity of coarse aggregate nemat quadri. Coarse aggregate specific gravity set set includes wire density basket with handle la052010 and polyethylene pail la052006 for weighing coarse aggregate samples while suspended in water. To determine specific gravity of coarse aggregate concrete practical coarse aggregates are particles greater than 4. Aggregate unit weight knm3 bulk density example knm3 normalweight 2. For assessment of the specific gravity of specified specimen of fine and coarse aggregates. The absolute volume of a 90lb sample of the aggregate is. The standard test methods used for the determination of specific gravity of coarse aggregate are described in aashto t 85 and astm c127. It is similar in nature to the coarse aggregate specific gravity test figure 1.
The relative density specific gravity, a dimensionless quantity, is expressed as ovendry od, saturatedsurfacedry ssd, or as apparent relative density apparent specific gravity. Specific gravity is a measure of a materials density mass per unit volume as compared to the density of water at 73. Specific gravity of aggregate test equipment gilson co. Laboratory test procedure for determining bulk specific gravity of superpave gyratory compacted specimens duration. If the fineness modulus is constant, the volume of coarse aggregate increase with size of the aggregate, or with the decrease in surface area of the coarse aggregate the main cause in variation in weight of cube found to be specific gravity of coarse aggregate. The coarse aggregate specific gravity test measures coarse aggregate weight under three different sample conditions. What is the limits for specific gravity of coarse aggregate. As preconized by siddique 2010b, the bulk specific gravity values of the mswi ash ranges from 1. Fineness modulus is generally used to get an idea of how coarse or fine the aggregate is. Specific gravity is the ratio of the weight of a given volume of aggregate to the weight of an equal volume of water. Specific gravity and water absorption for aggregates. The specific gravity of aggregates normally used in construction ranges from about 2.
Heavyweight aggregate those aggregate with high density and is used primarily in the manufacture of heavyweight concrete, employed for protection against nuclear radiation and as bomb shelter. Some lightweight shales not used in hma production can have specific gravities near 1. Therefore, multiplying the specific gravity and the density of water will result in the density of the aggregate itself, in units of mass per unit volume. The specific gravity of aggregates normally used in construction ranges from. Specific gravity and water absorption tests on aggregates. Low specific gravity generally indicates porous, weak and absorptive materials, whereas high specific gravity indicates materials of good quality. Fine aggregate specific gravity pavement interactive. Each country is likely to have their own local varian. Saturated surfacedry ssd, water fills the aggregate pores. Sfn 10081 62019 pit location laboratory number owner project number sampled from pcn submitted by date received. The methods are essentially the same, except for the.
Specific gravities can vary widely depending upon aggregate type. Fine aggregate specific gravity sample and pycnometer. Based on the findings of experiment 2, it was recommended that aashto t 85 be used for measuring specific gravity and absorption of coarse aggregate and the modified aashto t 84 and ssdetect methods be used for measuring specific gravity and absorption of fine aggregate. Study on tests fine and coarse aggregate engineering.
Bulk specific gravity also known as bulk dry specific gravity. Fineness modulus of different type of sand is as per given below. This procedure covers the determination of specific gravity and absorption of coarse aggregate in accordance with aashto t 8514. You asked about sources of error, not how the test works. Observation table for specific gravity of aggregate finer than 6. Astms construction materials technician series enables qaqc technicians in the construction industry to advance their skills using leading, selfguided, computerbased. The unit weight of heavyweight concrete varies from 2400kgm3 with sp. Astm c127 12 standard test method for density, relative density specific gravity, and absorption of coarse aggregate elearning course. Asg bsg ssd bsg od however, since the porosity of most rocks used in concrete is 1 to 2%, the values of all specific gravities are approximately the same.
It is similar in nature to the coarse aggregate specific gravity test. Aggregates having low specific gravity are generally weaker than those with higher specific gravity values. Specific gravity of fine aggregate sand is the ratio of the weight of given volume of aggregates to the weight of equal volume of water. An equilibrium or scale of volume of minimum 3 kg, decipherable and precise to 0. The standard coarse aggregate specific gravity and absorption test is. Take about 200gm of coarse aggregate sample in the pycnometer. They can either be from primary, secondary or recycled sources.
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