Experimental investigation of pervious concrete using fly ash and nano silica

Abstract

Pervious concrete (no fines concrete) is a concrete containing little or no fine aggregate; it consists of coarse aggregate and cement paste. It seems pervious concrete would be a natural choice for use in structural applications in this age of green building. It consumes less raw materials than normal concrete (no sand), it provides superior insulation values when used in walls, and through the direct drainage of rainwater, it helps recharge groundwater in pavement applications. The first pervious concrete was used in Europe and the united kingdom since 1930s for the building of single and multi storeyed houses, but had found little acceptance in rest of the world. Even though it is not yet widely used, pervious concrete is generally used for light duty applications, such as residential streets, parking lots, driveways, sidewalks, channel lining, retaining walls and sound walls. The aim of this study is to investigate compressive strength of pervious concrete by eliminating the fine aggregate; additionally investigate infiltration rate of pervious concrete. Referring to the available literature, it was attempted to mix cement & coarse aggregates at two different water-cement ratios. As the pervious concrete finds its wide application in parking areas, footpaths, garden paving, etc., higher compressive strength was not an objective. The focus of the current work was on providing adequate permeability to the concrete mass so that the water can easily pass through it. The slump required for the pavement work is exceptionally low. Therefore, production of zero slump concrete was aimed at. The wide use of the pervious concrete for the various applications mentioned above is the need of the hour. The water infiltrated through the pervious concrete would also contribute towards enhancing the ground water level i.e. it would facilitate ground water recharge.