Analysis of water migration in an earthen landfill cover with recycled construction waste

In this study, numerical analysis was conducted to investigate the effects of particle sizes on water migration in a three-layer landfill cover system using recycled concrete aggregates (RCAs). This cover system consists of a top fine recycled concrete aggregate (FRC) layer and a middle coarse recycled concrete aggregate (CRC) layer overlying a bottom silty refuse soil layer. Numerical simulations were performed to back analyse a flume model test data and further evaluate the particle size effects of RCAs on the effectiveness of the cover system. With the increase in rainfall duration, surface runoff reduced, while the lateral diversion increased pronouncedly. Nonetheless, no significant percolation is observed through the cover system using RCAs during 100-year extreme rainfall with different durations. Based on the results, the d10 of FRC is recommended to be from 0.2 mm to 0.5 mm.