Abstract:
Concrete being the most widely used material in civil engineering for infrastructural development. The improvement and further development of this material has always been on tips of civil engineers in their research projects. It has now been recognized that concrete with many of its newer combinations and additives in the form of cement based composites has improved its properties.
High performance concrete represents a recent development in the advancement of concrete materials technology. Now, it is established that high performance concrete is of high quality and lower cost. High performance concrete is not a commodity but a range of products, each especially designed to satisfy in the most effective way the performance requirements for the intended application. High performance concrete mixtures contain, higher cement content, lower w/c ratios, strong aggregates, cementicious materials like silica fume and high range water reducers. Such mixtures, when properly mixed, placed, consolidated and cured yield very high strength and excellent performance.
For this research the effects of different replacement levels of cement by silica fume (5%, 10% & 15%), incorporating the coarse aggregates from two major sources Sargodha and Margala were studied. All the mixtures were prepared with constant w/c ratio 0.25. Strength properties including compressive, tensile, flexure and modulus of elasticity were analysed. Optimum replacement level of cement by silica fume that satisfied the economical performance in terms of all the strength properties is identified. Potential applications in high-rise buildings, long span bridges and off-shore structures are suggested. Finally the research is concluded with further future prospects.
