Effects of Locust Bean Pod (Parkia Biglobosa) Extract on Workability and Strength of Concrete

Purpose: Predominantly in the northern part of Ghana and other neighbouring West African countries, the Locust Bean Pod Extract (LBPE), known for its adhesive and cohesive properties, has enjoyed high patronage in its incorporation in various traditional construction formulations, especially in the production of clay floor tiles and bricks for some time now. To justify the material’s continual use, this paper explored the impact of the LBPE on the properties of fresh and hardened concrete. Design/Methodology/Approach: LBPE was obtained by soaking the pods in 10g per litre of water for different extraction periods. Based on LBPE replacement percentages and soaking durations, 469 concrete cubes were formed from 9 different concrete mixes. The slumps for the various mixes and the strength of hardened concrete were tested after curing durations of 7 days to 28 days. Findings: The experimental results revealed that LBPE enhanced the strength of concrete and gave it more workable mixes than concrete made with ordinary water. X-ray Diffraction (XRD) analysis on the control indicates the presence of Oligoclase, whilst the LBPE samples indicate the presence of Albite. Scanning electron microscope (SEM) analysis revealed the differences in element composition of both the control and LBPE samples. LBPE extraction at 4 days and 75% LBPE replacement of water achieved 54.67% more 28-day strength and over 21% more workability than the control. Fourier Transform Infrared results indicate that tannins are the primary functional element in LBPE. Research Limitations: This study established that replacing water with LBPE significantly improves the workability and strength of concrete. The extraction at 4 days and 75% water replacement with LBPE yielded optimum results. Practical implications: This study provides a sustainable and low-cost solution to the mutually exclusive problem of increasing concrete workability and strength. Social Implication: This study will assist practising engineers in dealing with the issue of artisans increasing the water-cement ratio of mixes to obtain workable mixes, which results in weak concrete strength and subsequent failure of concrete structures Originality/ Value: This original experimental laboratory study addresses the problem of artisans using too much water to mix concrete to ensure workable mixes.