Clogging investigation of two layered steel slag pervious concrete incorporating ceramsites under rainstorm

To address the issues of excessive consumption of natural aggregates, prone to clogging under rainstorm, and poor purification performance in conventional pervious concrete, the two layered steel slag pervious concrete incorporating ceramsites has been proposed. In this study, a novel device was introduced to simulate the clogging process of the proposed pervious concrete under rainstorm. The effects of runoff depth, runoff velocity, specimen porosity, gravel gradation of clogging materials and runoff pollutants concentration on the permeability degradation of the proposed pervious concrete were investigated. Experimental results indicate that the clogging process of the proposed pervious concrete follows three distinct stages: rapid clogging, clogging rebound and stabilization. The increase in runoff depth, specimen porosity or runoff pollutants concentration leads to a progressive increase in permeability coefficient loss rate, while higher runoff velocity mitigates the clogging process. The reduction in permeability coefficient is significantly affected by both fully graded and fully fine gravel. Based on experimental research, the calculation method for the permeability coefficient of the proposed pervious concrete after clogging is developed using Tan's theoretical model. The results offer valuable insights for optimizing the design and performance assessment of the proposed pervious concrete.