Effectıveness of Locust Bean Epıcarp Extract on Re-vıbrated Concrete Usıng Pebbles from Bıda Envırons as Coarse Aggregate

Abstract

Purpose: In this research, the effect of re-vibrated concrete using locust bean epicarp extract and Bida natural stone (Pebbles) as coarse aggregate was presented. Design/ Methodology/ Approach: The concrete mix of 1:2:4 and water cement ratio of 0.5 was adopted respectively. One hundred and sixty-eight (168) concrete cubes were produced in six (6) batches, 28 cubes were produced for control (mix A= 0% LBEE + 100%OPC) and 28 for (0%, 5%, 10%, 15% and 20%) cement reduction respectively. Findings: The results of preliminary test of the aggregates indicate that they are suitable for concrete production and the chemical analysis of LBEE showed that it is a very good pozzolana. Concrete cubes were cast with re-vibration time lag intervals of 10minute for the period of 60minute re-vibration process and cured for 7 and 28days. The result shows that introduction of LBEE improve the compressive strength of concrete. The result obtained also shows that there is increase in compressive strength with the increase in revibration time lag of LBEE concrete, hence the maximum compressive strength was obtained at 60minutes for all batches. The maximum compressive strength obtained at 28days curing was 35.70N/mm2 for B (0% cement reduction) at 60% re-vibration which is higher than 34.0N/mm2 for control mix A. The optimum cement reduction of concrete made incorporating LBEE without re-vibration and the one with re-vibration is 5% and 20% respectively.