Laboratory Investigation on the Short-Term Compressive Strength of Microbial Laterized Concrete

摘要

This study investigates the effect of Bacillus subtilis JC3 on the compressive strength of laterized concrete. Taguchi method of experimental design which involved the use of orthogonal tables with three levels and three factors was employed. In all, 108 samples of 150mm×150mm×150mm concrete cubes cured in two media (water and nutrient broth) with a mix ratio of 1:2:4 were tested for compressive strength at 7, 14 and 28 days. The factors used were water/cement ratio, percentage laterite replacement for fine aggregate and concentration level of bacterial medium (added in different proportions as liquid for mixing the composite material). The results showed that Bacillus Subtilis JC3 generally enhanced the compressive strength and durability of the conventional concrete studied. The observed optimum values for water/cement ratio and bacterial medium for the constitution of concrete were found to be 0.50 and 20% respectively, however a negative trend was observed for laterite replacement for sand.