DEVELOPMENT OF HIGH PERFORMANCE CONCRETE USING MICROFILLERS

Abstract

Concrete is by far the most widely used manmade construction material and, it will continue to be so i.n the years and decades to come. It was the advent of prestressed concrete on the construction scene that triggered interest in high strength concrete (HSC). The construction industry has been continually striving to improve the strength of the concrete. As the practical and economical limit of HSC now approaching the 150 MPa mark, the ,emphasis has shifted to other properties such as high modulus of elasticity, high density, low permeability and better resistance to various forms to attack. As such it is being described by a more wide term "High Performance Concrete (HPC)". The selective use of materials, a different approach in the mix design procedure, special attention to compaction of concrete and stringent quality, control are essential to the production of HPC. With the availability of high strength cements, superplasticizers and microfillers, it is now possible to develop HPC only by normal methods. The objectives of present study are to design HPC mix using the locally available materials and to study the effect of different microfillers such as fly ash, silica fume and their combination on the strength development characteristics of HPC mixes. The present work also aims to study the effect of microfillers on stress-strain relationship and modulus of elasticity of HPC. The replacement of cement by microfillers has resulted in significant increase in 56 day compressive strength. The stress strain relationship have also Improved and the modulus of elasticity of HPC mixes was found to be increasing with increase in compressive strength.