PROPERTIES OF CONCRETE MADE WITH ORDINARY PORTLAND CEMENT PARTLY REPLACED WITH RICE HUSK ASH AND PULVERISED-FUEL ASH

Yunusa A. Alhassan and Danladi Egbunu

Department of Civil Engineering

Federal Polytechnic, Idah, Kogi State, Nigeria.

E-mail: alhassanay@gmail.com

ABSTRACT: The use of pozzolana as a Supplementary Cementing Material (SCM) in concrete production has become common all over the world. When properly used, pozzolanic materials can significantly enhance the properties of concrete. Laboratory study was conducted in Nigeria to investigate the properties of concrete made by partial replacement of Ordinary Portland Cement (OPC) with Rice Husk Ash (RHA) and Pulverised Fuel Ash (PFA) that were locally available in the country. Concrete cubes and cylinders were cast at a constant water/binder ratio of 0.6 and moist cured for 7, 28 and 56 days using the above cementitious materials. Measurements of the workability, compressive strength and porosity were determined. The results show that the use of ternary blend of OPC, RHA and PFA produces concrete with improved strengths and permeability at the low replacement level with RHA and PFA and at the later age in comparison to that of OPC concrete. Although, the results of the compressive strength of the concrete cubes made from the Portland-Pozzolana Cement (PPC) were not higher than that of the control, they can be used for masonry, non-structural works and foundations were low strength are needed.The porosity of concrete containing pozzolana reduces with the low replacement level of up to 20% of pozzolana, but increases with the 30% replacement level. The workability of the concrete made with RHA decreases with an increase in ash content compared to the PFA.