Particle size and analysis Opening of standard sieves" Sieve nunber Sieve opening 9.5mm 234800o 5.6mm 4.75mm 2.36mm 200mm 26 850um 3 600Lm 40 425m 5O 300Lm 60 250m Zo 212以m sO 180,m 100 150,m 120 125Lm 200 75 Im 230 63 Hm 270 53 Im 325 45 Hm 400 38 Im Adapted from USP23-NFI8.一、Particle size and analysis