Effect of Locust Bean Pod Extract (LBPE) as a replacement for water on the compressive strength of concrete

Abstract

This study investigates the effect of locust bean pod extract as replacement for normal mixing water on the compressive strength of concrete using water-cement ratio of 0.5 and a concrete mixing ratio of 1:2:4. The laboratory test conducted, consists of casting of sixty (60) cubes specimen 150mm x 150mm x 150mm and cured for 7 and 28days. The cubes were tested with their average compressive strength obtained from the best 4-cubes at each concentration. The result shows that the pod extract increases the strength of concrete by attaining maximum compressive strength of 37.59N/mm2 at 0.05kg/lt greater than the control which has 31.65N/mm2 at 0kg/lt. Chemical analysis of the extract revealed that the sum total of the combination of chemical compounds (SiO2 + Al2O3 + Fe2O3) was 50%. This shows that the locust bean pod extract is pozzolanic in nature and can be used to replace water up to 0.15kg/lt for good concrete performance that is better than the control.