Diagnosis of Low-Carbon Permeable Pavements: Bearing Capacity and Long-Term Clogging Behaviour

Abstract The need to encourage sustainable construction practices to conserve the rapidly diminishing natural resources increases. Moreover, increases in impermeable areas in urban regions increase flood risk and impose significant stresses on stakeholders. The research presented here was conducted on using recycled low-carbon materials in permeable pavement systems (PPS) to address this issue. Despite the worldwide usage of PPS, uncertainty and a knowledge gap remain regarding the impact of recycled materials on their structural and long-term clogging performance. To this end, the load-bearing capacity and long-term clogging behaviour of four 0.2 m 2 permeable pavement rigs made up of varying natural and recycled sub-base materials were evaluated in the laboratory. The recycled materials selected were crushed concrete aggregates (CCA) and cement-bounded expanded polystyrene beads (C-EPS), and the natural materials were basalt and quartzite aggregates. Accelerated 10-year clogging simulation with yearly hydraulic conductivity measurements was used to evaluate the long-term clogging behaviour of the rigs, whilst portable falling weight deflectometer (PFWD) testing was used to evaluate the load-bearing capacity. The results of the clogging simulation found that the hydraulic conductivity of all rigs declined exponentially and were of a similar pattern. This confirmed that the sub-base materials had little influence on the clogging behaviour of permeable pavements. The PFWD test, however, demonstrated that the sub-base materials impacted the load-bearing capacity of the rigs, but both CCA and C-EPS were suitable to be used in permeable pavements under different loading restrictions.