MANAGEMENT OF STORM WATER USING PERVIOUS CONCRETE INTERLOCKING TILES IN CHANDIGARH

Infrastructure development today has lead to increase in the impermeable surface which tends to increase the volume of runoff from the storms. With existing drainage systems designed for the removal of volumes upto a specific limit, it is area of concern for the management of this extra runoff flowing. This research infers to the design and laboratory test on the permeable concrete interlocking tile and pavement underneath to manage storm water. From the vast study area of Chandigarh city's road system, selected sectors i.e. 33, 35 and 37 were taken to find the hydraulic response. Tests were conducted to find the infiltration rate and other soil properties of the native soil of the selected sectors. The permeable concrete interlocking tile is designed with a specific consideration over porous concrete pavements determined to release water into the stone reservoir and the drainage system at the same time. Various tests were conducted to determine the characteristics and properties of the material selected for the design mix. The mix designed for PCIT was prepared by 10% fines to total weight of aggregate with cement aggregate ratio of 1:4 and strength was determined by compressive strength, split tensile strength as well as flexural strength tests. As the PCIT should be permeable enough to allow large volumes of water through it therefore its permeability was calculated with the help of Constant head permeability test in laboratory. PCIT pavement model was prepared in laboratory to find the hydraulic response during a simulation of various rainfall events. The model construction comprised a series of layers of material of various sizes bottom to top: native soil (300mm), coarse aggregate (300mm), fine sand and aggregate (50-50mm) with PCIT (200mm) on the top of the model. The model was supplemented with various rainfall intensities of 12mm, 20mm, 40mm, 60mm, 80mm and 120 mm for duration of 15, 30, 45 and 60 minutes in order to calculate the response of the PCIT on the area where it will be provided. Results from the simulations showed that the pavement responded in a similar manner seen from the trend of the outflow curves for the higher intensities after the first outflow. Results from this study concluded that the PCIT in combination to pavement system is capable of handling large volumetric rainfall from the addressed catchment area. The PCIT performance showed it has 76% infiltration to pavement and 24% discharge to drains for the overall durations of the rainfall and increase with the intensity of downpour. Whereas, the pavement underneath is capable of storing more than 66% of rainfall. The maximum retention in the stone reservoir was of 85.7%. The model was further developed for specific selected sites for which the runoff from the sites and area where the PCIT will be provide is calculated by rational equation method. It was concluded that there will be decrease in nearly 5% of the runoff from the model when it is laid in combination with calculated stone reservoir depth of 458.5mm, 478mm and 472.5 mm for sector 33, sector 35 and sector 37 respectively. It is found that PCIT laid on smaller area removed generous volumes for a large catchment area therefore reducing the cost of re-constructing the roads to permeable as well.