Enhancing the Properties of Laterite Rock Concrete using Metakaolin

The effect of replacing sand with metakaolin MK on the workability and strength properties of laterite rock concrete was investigated. MK was introduced at 0 %, 5%, 10% and 15% replacement levels for sand. Results show that as the percentage of MK increases, the workability as measured by the slump and compacting factor test reduces. However, the introduction of superplasticizer increased workability substantially and comparable to the control concrete consisting of granite aggregate. Furthermore, the compressive and splitting tensile strength measured at 3, 14 and 28 days showed optimum performance at 5% MK replacement beyond which there was decline on further addition of MK. Results also showed that the deflocculating effect of superplasticizers on MK consistently improved the compressive strength and splitting tensile strength of laterite rock concrete for all mixes.