Concrete at water-cement (w/c) ratio of 0.30 and 0.35 containing rice husk ash (RHA) at a low specific surface presoaked with equal weight of water wascured in water and ambient air (uncured). The RHA was presoaked in equal mass of water prior to mixing to reduce water demand in fresh concrete usually associated with concrete containing RHA. The aim was to determine the optimum ordinary Portland cement (OPC) replacement with RHA resulting from the reactivity of presoaked RHA and the effects of presoaked RHA on durability properties (coefficient of water absorption and sorptivity) of concrete at the age of 90 days. At w/c ratio of 0.30, OPC replacement with 20% RHA resulted in higher compressive strength compared to control for both water cured and uncured cubes. Improvements in durability properties of concrete resulting from the use of presoaked RHA were recorded.
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