The Effect of Addition of Indigenous Silica Powder from Lampung on the Concrete Performance after 1 Year Curing Time

摘要

The indigenous silica powder from Lampung was used as an additive in concrete mixture to investigate the effect of its addition on the concrete performance. The silica powder was pre-treated using planetary ball mill for 1 h and 130 hrs to obtain silica particle size of 10 and 2 μm, respectively. The obtained silica powder was then mixed with the concrete mixture and was cured for 1 year before further test. The analysis of hydration reaction between Portland cement and 20wt% silica powder showed that 30-50wt% calcium hydroxide was significantly consumed after curing for 1 year. Particle size reduction of silica powder increased its reactivity by 25-40%. The bending strength of cured sample was lower than that of standard sample. Microstructure and composition analysis showed the existence of alkali elements which can improve the possibility for the alkali silica reaction to occur.