Effect of Fly Ash and Fibres on Strength and Permeability Characteristics of Pervious Concrete

Abstract

Conventional normal cement concrete is generally used as construction material of buildings. The impervious nature of concrete contributes to the increased water runoff into drainage system, over-burdening the infrastructure and causing excessive flooding in built-up areas. Pervious concrete has become significantly popular during recent decades, because of its potential contribution in solving environmental issues. Pervious concrete is a type of concrete with significantly high water permeability compared to conventional concrete. It has been mainly developed for draining water from surface to underground, so that storm water runoff is reduced. Due to high water permeability then normal concrete, pervious concrete has very low compressive strength. The characteristic of high permeability of pervious concrete contributes to its advantage in storm water management. However, the mechanical property such as low compressive strength limits the application of pervious concrete to the roads having light volume traffic. It is observed form previous studies that the strength of pervious concrete can be enhanced by substituting some of the cement with other materials, such as fly ash and fibres. The objective of present study was to make pervious concrete mix with high strength and pore properties by partial replacement of cement with fly ash and using steel and glass fibres. For this purpose cubes beams were casted with and without replacement of cement with flyash and addition of steel and glass fiber by total weight of concrete mix. Test such as compressive strength, flexural strength, total porosity and Infiltration rate were performed. It was observed addition of fly ash decreased the compressive as well as flexural strength of the pervious concrete. Further, incorporation of 1% steel fibres by weight of concrete mix was found adequate in achieving high strength and permeability, when compared to control mix concrete