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.

This study aims to resolve the “secondary activation” challenge when erecting structures over goaf zones by employing a novel grouting and filling material. It delves into the performance degradation of the innovative ECS soil grouting filling material (ESGF material) within the goaf’s ionic erosion context. Erosion tests were performed on ESGF material specimens with varying mix designs to mimic the sulfate and chloride erosion scenarios commonly encountered in practical engineering. The macro-mechanical properties and microstructural changes of ESGF materials under ionic erosion environment were systematically investigated by various testing methods, such as unconfined compressive strength (UCS), SEM, XRD, TG, FTIR, and Raman. The findings indicate that both sulfate and chloride erosion lead to a reduction in the strength of the ESGF material. As erosion progresses, the specimens experience a mass increase followed by a decrease, with their strength exhibiting a consistent downward trend. In sulfate erosion conditions, the buildup of expansion product like ettringite (AFt) and thaumasite (TSA) inflicts substantial internal structural damage. Conversely, Friedel’s salt, the primary product of chloride erosion, exhibits relatively weaker expansiveness, and chloride concentration exerts a less pronounced effect on material degradation. Moreover, the cementitious material content and the proportion of quick-setting component play a significant role in determining the ESGF material’s resistance to erosion. By adjusting the quick-setting components ratio in response to changes in the water content of soft soil, the anti-ion erosion performance of solidified soil can be effectively enhanced. Notably, curing with a 5% sulfate maintenance could significantly improve the erosion resistance of ESGF material. This suggests that ESGF materials can be used without concern for curing issues in high-salinity environments during grouting. The research addresses the root cause of goaf subsidence while facilitating the recycling of solid waste, offering an environmentally friendly solution.