Determination of Sulphate Ion Concentration in Some Ground Water in the Cape Coast Metropolitan Area, Central Region, Ghana and Its Effects on Concrete Brick with Admixture of Sawdust Ash

The admixture was prepared from Sawdust waste (SDA) and was pyrolysis by placing it in a Nabertherm (SN224350) at a controlled condition. The SDA was characterized using X-ray diffraction technique and applied as an admixture in producing concrete brick with good cementitious properties. Some key factors that contribute to concrete durability such as compacting, curing ages and the essence of quality water were taking into accounts.The sulphate ion concentration in ground water source was determined and its effects on concrete brick with 5 % SDA, 15 % SDA and 25 % SDA replacement were assessed and its compressive strength reported.5% replacements of sawdust ash, concrete brick (no curing) was found to have suffered greater attack at 28 days immersion period as compared to concrete bricks cured for 3 days and 7 days. 3 days curing and no curing of concrete brick showed a greater resistance against Sulphate intrusion with 25% sawdust ash replacements at 28 days immersion period. Premature curing of concrete brick for 7 days, with an increase in sawdust ash replacement were even more vulnerable to sulphate ion attack than concrete brick with 3 days curing and no curing.