ABSTRACT
This study had investigated the admixture properties of plantain peel ash through a series of laboratory experiments. This was targeted at obtaining an effective admixture while relieving the environment from the menace of environmental pollution arising from indiscriminate disposal of agricultural wastes. Plantain peel ash was blended with dry cement at 11 different percentage additions at 0%, 0.2%, 0.4% up to 2.0% for cement pastes and mortar. The cement paste was tested for setting time and soundness to BS EN 196:3-1995 while mortar prisms were tested for flexural and compressive strength to BS EN 196:1 1995, after which, scan electron microscopy (SEM) was carried out on samples of mortar tested at 28 days. Setting time tests results has indicated a retardation in setting of the cement paste with the addition of plantain peel ash whereas the early strength development of the cement was delayed by the ash additions as indicated by the strength tests. From the soundness test results, the ash was found to have no impact on the soundness of the cement as the maximum expansion recorded was 1mm at 0.2% and 1.0% ash contents. The result of the SEM analysis indicated that a mortar prism with higher ash contents tends to have a more porous microstructure. Based on the results, the ash was categorized into a class of set retarding admixture as per the provisions of BS EN 934 part 2(2000) while the optimum ash content recommended for use is 1.0% by weight of cement.