FLEXURAL STRENGTH OF REINFORCED CONCRETE BEAM WITH LOCUST BEAN POD EXTRACT AS REPLACEMENT FOR WATER

Abstract

Study on the flexural strength of reinforced concrete beam using locust bean pod extract (LBPE) as a replacement for water is presented. Chemical test of the extract and other preliminary tests on aggregates were carried as materials that were used. The chemical composition of LBPE shows that it is a good binder (pozzolana) and contains all major oxides found in Ordinary Portland cement (OPC): SiO2 (49.993 %), Fe2O3 (6.342 %) and Al2O3 (18.966 %). Sixteen (16) beams specimens of size 0.15 m × 0.15 m × 0.6 m doubly reinforced with 12 mm diameter steel bars as major reinforcement and stirrups of 8 mm diameter evenly spaced were cast. Four beams were cast for each replacement of water with 0, 5, 10 and 15 % LBPE and cured for 28 days. Flexural test results show that the flexural strength from the average of the best three values for each replacement, was maximum (8.59 N/mm2) at 10 % replacement of OPC with LBPE and higher than the control (8.11 N/mm2) at 0 % replacement. The LBPE concentration is seen to affect the flexural strength of reinforced concrete beams positively.