The impact of fly ash and structural fiber on the mechanical properties of concrete

Abstract

Structural concrete is prone to micro-cracks even before the structure is subjected to the design loads. These cracks appear mainly due to drying shrinkage and other causes of volume changes. These small-scale cracks induce large cracks and the improved miniaturized scale cracks, resulting in inelastic deformation of concrete. To reduce the development of such micro-cracks, often fibers of artificial and natural origin are used in concrete to strengthen it against cracking. Researchers have developed high strength concrete using modern fibers like glass, carbon, polypropylene, aramid fibres and structural fibers. Thermal power plant waste by-products like fly ash and bottom ash hugely suffer from the problem of waste disposal. Fly ash is used in the fiber reinforced concrete to make it dense, and to reduce drying shrinkage which helps to arrest the shrinkage cracks. This study has been conducted for understanding the mechanical behaviour of concrete by adding the structural fibre at 0.02%, 0.04%, 0.06%, 0.08% and 0.1% by weight of cement and fly ash partially replaces the cement by 10% of the weight of cement. The results were then compared with M35 grade conventional concrete. The results were very found promising compared to conventional concrete wherein, the fly ash binds the concrete mix to make it dense. The fly ash is very cheap, eco-friendly, economical and effective in enhancing the strength of concrete compared to ordinary Portland cement.