Influence of Water Cement Ratio Variation on Properties of Millet Stem Ash (MSA) Concrete

The influence of varying the water cement ratio on the compressive strength properties of concrete are substantial factors in the design and construction of concrete structures. Compressive strength directly affects the degree to which the concrete can be able to carry load over time. These changes are complemented by deflections, cracks etc. in concrete structural elements. The purpose of this research was to measure the effect of water cement ratio on properties such as compressive strength, slump, flow and workability properties of Millet Stem Ash (MSA) mixes with OPC at 5 %, 10 %, 15 %, 20 % and 25 % to form concrete and to evaluate whether they are acceptable for use in concrete structural elements. A normal concrete mix with cement at 100 % (i. e. MSA at 0 %) with concrete grade C25/30 that will attain an average strength of 30N/mm2 at 28days was used as a control at design water/cement ratios of 0.60 and increased to 0.65 and aggregate grading of (0.5-32) mm from fine to coarse was tested for (1) Compressive Strength, (2) Slump and Flow Test The results and observations showed that the concrete mixes from MSA at 5 % - 25 % ratios could be used as a partial replacement to cement at these percentage mix ratio compared with the control concrete, an increase in the water cement ratio showed a significant decrease in the compressive strength and an increase in workability. Therefore, it is important that all concrete mixes exude acceptable design water-cement ratio for compressive strength characteristics for use in structures, water cement ratio is a significant factor.