The Effect of Adding Synthesis Silica from Rice Husk as Cement Substitution for High Strength Concrete

Abstract

The synthesis of silica from agricultural waste was conducted. The thermal decomposition was conducted at 700°C which yields white-brown silica powder. Acid mechano-chemical method was done to reduce the size particle of silica and homogenize the distribution particle. The variables used were the rotational speed of planetary ball-mill at 22 rpm and the addition of acid (HCl 1M). Under controlled burning, the highly reactive ash (silica products) that is produced can be used as a supplementary cementing material or in the production of high strength concrete (HSC). The samples were tested during its 28th day to know its compressive strength.