SUITABILITY OF MAIZE COB ASH AS A PARTIAL REPLACEMENT OF CEMENT IN SANDCRETE BLOCKS
Anowai, S. I., Ishaya, A. A., Zakka, P. W., Yahaya, A. M. & Oyelade, O.M.
Department of Building
University of Jos, Jos Nigeria
E-mail: anowaisolomon@yahoo.com
ABSTRACT: This research is aimed at determining the suitability of the use of Maize Cob Ash as partial replacement of ordinary Portland cement (OPC) in the production of Sandcrete Blocks. The maize cob used in this study was sourced from Jengre village in Bassa Local Government Area of Plateau State. The maize cobs were properly dried and burnt to ashes completely at the temperature of 500-6000C in a furnace. Mix ratio of 1:6 (cement: sand) was used in this study. Water cement ratio of 0.5 was adopted in this study. OPC was partially replaced with maize cob ash (MCA) in varying percentages of 10%, 20% and 30% by weight. The block samples were moulded and cured for 7, 14 and 28 days. The compressive strengths of the blocks were tested by crushing using compressive test machine. The compressive strength of the blocks was observed to increase with increasing days of curing. Sandcrete block samples made with 10% and 20% replacements of OPC with MCA achieved compressive strengths of 4.05N/mm2 and 2.65N/mm2 respectively at 28 days. These satisfied the minimum compressive strength requirement of 3.45N/mm2 and 2.5N/mm2 for load bearing and non load bearing walls respectively specified by NIS:87 (2004) for sandcrete blocks. Blocks made at 10% and 20% percentage partial replacements of OPC with MCA also satisfied the maximum water absorption requirement of 12% specified by Nigeria Industrial Standard (2004) for sandcrete blocks. It is thus recommended that OPC should be partially replaced with 10% and 20% MCA in sandcrete block production for load bearing walls and non-load bearing walls respectively.
Key Words: Maize cob ash, Sandcrete block, partial replacement of cement, compressive strength, Water absorption.
