Infiltration characteristics of landfill cover system made from recycled materials

For sustainability and cost consideration, construction and demolition waste have been explored for their applications in civil engineering. In this final year project, recycled concrete aggregate (RCA) and recycled asphalt pavement (RAP) are selected as potential candidates for landfill cover system. The purpose of the project is to study the infiltration characteristics of RCA and RAP using infiltration column. The infiltration experiments were performed in two rainfall rates for RCA and three rainfall rates for RAP. Finite Element Software SEEP/W was also used to study the effect of different rainfall rates, thickness of soil layers and coefficient of permeability in RAP. Drying SWCC was determined by using Fredlund & Xing (1999) best fitted equations and Wetting of SWCC were estimated by using Feng & Fredlund (1999) scaling method. The coefficient of saturated permeability of RCA and RAP were determined using triaxial apparatus. Then the hydraulic conductivity of both materials is estimated in SEEP/W using Fredlund & Xing fitting parameters. The hydraulic conductivity of RAP is higher for matric suction less than 2.2kPa. Based on the experiment results, it is observed that RCA has lower hydraulic conductivity (0.00017m/s) and can be used as cover soil layer in the landfill cover system. Runoff is likely to occur in RCA and thus can minimize the infiltration of water into the cover system.RAP has higher hydraulic conductivity (0.00083m/s) and is suitable to use as drainage layer in the landfill cover system. RAP can help to drain the water and improve the water storage of cover soil layer.Bachelor of Engineerin