Abstract

Porous Asphalt Pavements are considered to be amongst the fastest growing technologies in pavement engineering. They are an alternative to traditional asphalt concrete that enhances society, benefits the environment and promotes economy. The prime reason for employing a porous pavement is to add hydrologic benefit to the roadway. These pavements allow the water to freely drain through the layers. In this study, the different porous asphalt gradations were studied and based on the data a relationship was developed between the void ratio and permeability. The main aim was to study the effect of porous asphalt pavements on the surface runoff reduction for Bangalore City. The hydraulic behaviour of the Porous Asphalt Pavement was analysed using HYDRUS 1-D that is a freeware Software. The pavement produced runoff at 50 cm/hr in case of free drainage condition and at 90 cm/hr in case of seepage face condition. A comparison was made by using the parameters of a single porosity model in dual porosity model which produced a runoff for free drainage at 40 cm/hr and at 90 cm/hr for seepage face condition. The modelling of Porous Pavement was done in SWMM which is a freeware software to assess the impact of pavement thickness on the runoff produced for different rainfall intensities. A relationship between the pavement thickness and runoff/rainfall ratio was developed. A comparison in SWMM was made on the pavement with and without Low impact development technique i.e a porous pavement. The results showed that there was a decrease of about 80% in runoff production after the implementation of Porous Pavement. Different LID Techniques such as the bioretention cell, infiltration trench were analysed to see the effectiveness of the Porous pavements. Assessment of the porous pavements justified its adoption for flood mitigation purpose and these pavements can be considered as a viable solution for urban areas where the water retention on the surface leads to the pavement deterioration.