No abstract

Oil palm kernel shell (OPKS) is an organic lightweight aggregate (LWA) used as coarse aggregate in tropical countries for concrete in low-cost buildings. Concrete mixture proportioning is used to calculate the quantities of different constituents required to achieve different properties. For LWA concrete with mineral aggregate, there exist mix design methods that follow rigorous sequence of steps that consider performance specifications. However, no such method exists for concrete using organic coarse aggregate, namely, OPKS. The methods that exist for OPKS concrete that satisfy technical specifications for structural lightweight concrete (LWC) are based on trial and error or empirical methods. With trial and error method, it is not always possible to predict the value of specific properties of the concrete; however, engineers are mainly concerned with obtaining specific properties when proportioning a concrete mixture. The present topic presents a structured method for trial mix proportioning of structural LWC using OPKS as coarse aggregate. Based on the principle of the absolute volume method in ACI 213, the method is presented, following the below headings: (1) properties of constituents of OPKS concrete; (2) mix design procedure; and (3) results and discussion. Technicians in tropical oil-palmproducing countries for low-cost buildings can use the presented method.

The present study is related to the simple bending performance of a structural element made of Oil Palm Kernel Shell Concrete (OPKSC) reinforced with Borassus Aethiopum Mart (ronier). An experimental program with the use of three (03) distinct approaches of formulation was developed. These are respectively the formulation approaches proposed by Gibigaye et al (Gibigaye et al., 2017) and Yasmine et al (Traore et al., 2015) for OPKSC and the one proposed by DreuxGorisse for conventional aggregate concretes that served as control concrete. Reinforced roast concrete beams of size 150 mm × 150 mm × 910 mm were developed in accordance with NF EN 12390-1 and subjected to four (04) point bending until failure. It was observed an improvement of the bending strength of the OPKSC compared to the conventional aggregate concrete with a rate ranging from 3 to 80% depending on the type of formulation used. Similarly, the use of plasticizers improves the bending strength of OPKSC by more than 75%. Moreover, we notice the appearance of the first cracks as soon as the applied load reaches 60% of the breaking strength in bending which emphasizes the ductile behavior of OPKSC reinforced with roast. The OPKSC reinforced with ronier is a material suitable for use in the bent elements of the structure of lightly loaded buildings.