Maize-cob ash as filler in concrete

This technical note discusses an innovative use of maize-cob ash (MCA) as a filler in concrete. MCA in the range of 0-30% was used as a partial replacement for ordinary portland cement in a concrete of mix ratio 1:2:4:0.6 (cement: sand: coarse aggregate: water-cement ratio). Fresh concrete properties, compressive, split tensile strengths, and modulus of rupture were measured for concrete mixtures with MCA within the investigated replacement levels. The results showed that the setting times of MCA concrete increased with higher ash content, while the compressive, split tensile strengths and modulus of rupture showed a reverse trend. It was further observed that almost all of the studied specimens attained over 70% of their 28-day strength at seven-day curing.