Evaluation Of Mechanical Properties Of Palm Oil Fuel Ash (pofa) Blended – Granite - Gravel Concrete

3.2 Methodology
3.2.1 Grain Size Analysis of Aggregate
Grain size analysis is the determination of the size grain of particles present in a soil. It is expressed as a percentage of the total dry weight. Two methods are generally used to find particle size distribution of soil:  (1) Sieve analysis. (2) Hydrometer analysis. The sieve analysis is generally applied to the soil fraction larger than 75 μm (retaining on the No. 200 Sieve). Grains smaller than 75 μm (0.075 mm) are sorted by using sedimentation process (hydrometer analysis). Therefore, the study used sieve analysis method instead of hydrometer method.
3.2.1.1 Sieve Analysis Procedure
Oven dried the aggregate sample, allowed it to cool. Then took 431g of oven dried soil. Weighed each sieve and a pan to be used WO (the made sure each sieve was cleaned before weighing it, by using a brush to remove grains stuck in mesh openings). Arranged the stack of sieves so that the largest mesh opening was at the top and the smallest was at the bottom and attached the pan at the bottom of the sieve stack. Poured the dried sample on the top sieves. Added a cover plate (to avoid dust and lost particles while shaking). Placed the stack of sieves in the mechanical shaker and shake for 10 minutes. Removed the stack of sieves from the shaker, and measured the weight of each sieve and the pan with the soil retained on them WF. Subtracted the weights obtained in step (2) from those of step (6) to give the weight of soil retained on each sieve. Their sum was compared to the initial sample weight; both ensured to be within about 1%. Because if the difference is greater than 1%, too much material was lost, and weighing and/or sieving should be repeated /WF – WO/ > 1%.