Fracture Behaviour of Concrete with Sawdust Replacementunder Uniaxial Compressive Loading

Abstract

The mechanical strength of concrete made from Ordinary Portland Cement with sawdust replacement has been studied in this paper. The percentage replacements of aggregates by sawdust were 0%, 25%, 50%, 75% and 100%. The size of the test sample concrete adopted was 400 mm í— 200 mm í— 100 mm. The concrete was mixed, placed and compacted. The samples were removed from their moulds after 24 hrs and allowed to cure for 7, 14 and 28 days as required. Compressive and Flexural tests were performed on the test samples. Results show that the flexural strength of the concrete increases as the curing days increase but decreases as the percentage of sawdust increases. The compressive strength also decreases as the percentage of sawdust increases. As the number of curing day increases and the percentage of sawdust decreases, the harder and stronger the concrete produced becomes. Optimum replacement of sand with sawdust was found to be 20 % which satisfies the BS 1881 Part 4 (1970) code requirements for strength.