Hydraulic behavior variation of pervious concrete due to clogging

摘要

During the rainfall, different types of sediments are transported (organic and inorganic) and can end up decreasing the hydraulic efficiency of Pervious Concrete (PC). This phenomenon is known as clogging and occurs naturally in the PC due to its high area exposed to the weather. This study aims to identify and characterize the phenomenon of clogging in PC with natural aggregates and recycled aggregates, subjected to three types of sediment: two types of sand (Sand 1 and Sand 2, respectively) and a mixture of sand and clay (S?+?C). Besides, this research aims on proposing a maintenance plan to avoid loss of functionality of structures produced with PC. To fulfil these aims, the constant head permeability test will be adapted to evaluate the variation of permeability (k) during the clogging process. The results show that PC with recycled aggregates have the best hydraulic performance when compared with PC with natural aggregates. The results present values of 17.5 % and 19.6 % of porosity, and 6.2?mm/s and 10.0?mm/s of permeability for natural and recycled aggregates, respectively. Regarding clogging phenomenon, natural aggregate PC presents permeability reductions of 50 % (Sand 2), 60 % (S?+?C) and 70 %, (Sand 1) whereas in the case of recycled aggregate the maximum reduction was 30 % (S?+?C), 40 % (Sand 1) and 50 % (Sand 2). These results show the hydraulic advantage of implementing the use of recycled aggregates for PC production. On the other hand, the results show that a maintenance cycle of 5 years would make possible an increasing of the hydraulic life of PC independently of the type of aggregate used.