THE EFFECTS OF PERCENTAGE COMPOSITON OF MILLET STEM ASH (MSA) AND WATER CEMENT RATIO ON THE PROPERTIES COMPOSITE CONCRETE

Water cement ratio and the materials used in making concrete plays significant roles on the compressive strength properties of fresh and hardened concrete. Compressive strength directly affects the degree to which the concrete can be able to carry load over time. The load carrying capacity, cracks, resistance to fire attack, thermal changes, resistance to aggressive action in aggressive environment are often based on the composition and the grade of concrete. This paper presents comprehensive report on 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. The results showed that the concrete mixes from MSA at 5% - 25% ratios could be used as a partial replacement to cement