| The two most common methods of achieving high performance in concrete are reduced water, and matrix modification through pozzolans. In this investigation, the effects of water content and cement replacement with metakaolin at various levels were studied experimentally. The water-to-binder ratios selected were 0.35, 0.30, and 0.25. For each series of water-to-binder ratios, four levels of cement replacement with metakaolin were selected: 0, 5, 10, and 15%.; Four critical aspects of concrete performance were investigated, namely: ultrasonic pulse velocity, compressive strength, permeability, and drying shrinkage. Test results indicated that metakaolin significantly contributes to high performance in concrete, i.e., increase in compressive strength and ultrasonic pulse velocity, reduction in permeability and shrinkage. Contribution of metakaolin to achieve high performance was more significant than reduced water content.; Using statistical analysis, empirical models were developed to correlate pulse velocity with strength, and the effects of water and metakaolin content on concrete performance were quantified. |
