Study the Effect of Joints, Block Shape and Pavement Pattern on the Permeability of Concrete Block Pavement (Interlock Pavement)

Abstract

Gaza is facing an unprecedented increasing the numbers of buildings, concrete ceilings, paving main roads and many other vital projects. This increases the runoff of rain water and possibility of infiltration/drain to the aquifer. This study aims to determine the impact of the shape, pattern and joints of concrete block pavement (Interlock) in places which have low loads such as squares, car parking, stadiums,…. etc. to infiltrate the water through joints. In this study, several experiments were conducted to measure the impact of the joints, shape, and the pattern of pavement on the water permeability in concrete block pavement through several models on pavement which has an area of 1m2 in order to find the pavement permeability percentage and to reach the highest permeability percentage possible without runoff of water on the surface. This study contains five models for different block type, joints between block and different pattern pavements, with three different base course under pavements and five scenarios of gradually intensity of rainfall (15, 30, 45, 60, 120 mm/h) over a period of 60 min. The results showed that the water permeability of rectangular block pavement 10 x 20 cm have the best permeability percentage, where it was noted that the water permeability percentage in the intensity of rainfall at 15 mm/h amounted to about 76% without any surface runoff, while at the intensity of rainfall 120 mm/h water permeability percentage did not exceed 32.5 % with high surface runoff in the existence of sand layer under the tiles. When replacing the sand layer with a coarse aggregate layer, the permeability percentage reached 89.6% in the low intensity of rainfall and 75% in the largest intensity of rainfall and less of surface water runoff was observed. The results showed that the use of coarse aggregate "Adasia" (0/12.5) mm gives slightly higher permeability percentage than the use of aggregate "Simsimia" (0/9.50) in the bottom of the tile layers, and without using sand in the bottom layer gives very high permeability percentage. When changing patterns of tiles, the results didn't show significant effect on permeability percentage through the intensity of water mentioned above. As for the increase of joints between interlock tiles, no large effect has been noticed in the percentage of water permeability during low intensity of water, while little increase was observed in the water permeability during the high water intensity.