The Use of Palm Kernel Shell Ash as Cement Extender in Concrete

ABSTRACT 

The national housing policy of Ghana which was approved by cabinet in 2010, advocates the use of local building materials for the construction of buildings. It is against this background, that in recent years many studies have been conducted to find cheap but useful local building materials to replace the conventional ones which are to some extent expensive. Cement is one of the most important elements in building construction works which is relatively expensive. This research seeks to study the possibility of utilizing palm kernel shell ash (PKSA) as cement extender in concrete production. The study aimed at finding the chemical composition of PKSA, strength and durability properties of concrete produced from OPC with partial replacement of PKSA. The palm kernel shell was burnt, sieved and was tested at a chemistry laboratory and then compared with the chemical composition of OPC. The PKSA was used to prepare concrete cubes at replacement levels of 0%, 5%, 10%, 15% and 20%, cured for 28 days. From the study, it was evident that PKSA contains chemicals such as Si02 (silicon), Al203 (aluminium), Fe203 (iron oxide), CaO (calcium oxide), MgO (magnesium oxide) and K2O (potassium oxide) which are active ingredient in OPC but are not at the required levels. The PKSA replacement percentage in concrete mix improved workability but water absorption rate was comparatively high. Compressive strength declined as PKSA increased in the mix as well as density. The study showed an inverse correlation between compressive strength and PKSA percentage replacement levels. Following the high water absorption rate of PKSA concrete, it was not recommended for concrete works in water-logged areas. Despite the reduction in strength of PKSA concrete, 5% replacement is recommended for normal concrete works.