The purpose of this lab is to determine the particle size distribution of the fine and coarse aggregates by sieving.
Equipment and Material
Balance, sensitive to within 0.1% of the weight of the sample to be tested
Standard sieves for grading of fine aggregates- 4.75 mm, 2.36 mm, 1.18 mm, 300m, 150m (# 4, 8, 16, 50 and 100)
Standard sieves for grading coarse aggregates- 1 ½ in., 1 in., ¾ in., ½ , 3/8 in., 4 in, plus a 4.75 mm(#4 sieve)
Fine (0.5 Kg) and coarse (2 to 20 Kg depending on maximum size from 9.5mm to 50 mm (3/8 to 2 in.)) aggregate samples.
Sieve shaker supplied in lab
Test Procedure
For samples we use the dry aggregates from the specific gravity and absorption tests of coarse and fine aggregates. Then, we continue sieving until not more than 1% by weight of the residue passes any sieve during 1 min. For the wet analysis procedure, after weighting the dry aggregates, cover with water, agitate, and pour off the washwater containing suspended particles. We repeat this until the washwater is clear. Next, dry the aggregate a second time at 230◦ ± 90◦ and weigh.
Explanation of computation
Computation: Using table 1 (sieve analysis for fine and coarse aggregate), we calculate percentages on the basis of total weight of the sample. Also, compute the percent of material retained on each sieve and percent of material finer than for each sieve size for both the coarse and fine aggregates. Follow the procedure for the determination of all minus #200 (pan) mineral aggregates by the wet analysis. And then we plot the result on graphs which ordinate is the total percent by weight passing a given size on an arithmetic scale.
Discussion
Sieve analysis is one type of mechanical analysis which determines the size range of particles present in a soil, expressed as a percentage of the total dry weight or mass. Sieve analysis consists of shaking the soil sample through a set of sieves that have progressively smaller openings. The results of