CHARACTERIZATION OF LIGHTWEIGHT CONCRETE IMPREGNATED WITH CEMENT AND CAMEROONIAN CHARCOAL AS COARSE LIGHTWEIGHT AGGREGATE

This paper reports the results of a study on the formulation and characterization of lightweight concrete made with Cameroonian charcoal as coarse lightweight aggregate. Lightweight concrete is an old material and has been known around the world for over a quarter of a century. They are experiencing a renewed interest, which seems quite deserved because of their properties; it belongs to the family of special concretes. These characteristics suggest new applications. Lightweight concrete has low density than conventional concrete and the use of concrete of low density contributes to the reduction of the weight of the elements built with this concrete and subsequently the dimensions of the load-bearing elements, resulting in the reduction of the forces transmitted to the ground by the foundations, and consequently the dimensions of the latter, which allows the construction on soils of low bearing capacity. In this study, we first determined the characteristics of the constituent materials of our lightweight concretes, and then we formulated our lightweight concretes through two distinct formulation methods, namely the Dreux-Gorisse method and the progressive introduction method. Following these formulations, we have made several samples of lightweight concretes. Using laboratory tests, we have determined some of the physical and mechanical characteristics of these lightweight concrete samples. The results showed that when the charcoal content increases in the concrete, its water absorption rate increases. This is accompanied by a decrease of the mechanical strength. The mechanical strength of concrete evolves with time. The tensile strength is about 5 times lower than the compressive strength. The lightweight concretes developed are applicable for masonry bricks production in accordance with SANS 1215, NF DTU 20- 1 (1999), NF P 14-304 (1983), NF EN 771-3 (2011) and NF EN 771-3 / CN (2012)