Analysis of Mesostructure Characteristics and Clogging Mechanism of Pervious Concrete Based on CT Scanning and Image Processing Techniques

This study utilized CT scanning and image processing techniques to extract and analyze the internal mesostructure and cement paste distribution of porous concrete. The effects of the mesostructure and cement paste distribution on the compressive strength and permeability were studied. Additionally, the research explored the blockage mechanisms and morphology in porous concrete, with CT scanning used to map the distribution of blockages within the material. The results indicate that the impact of the aggregate particle size on the compressive strength is much less significant than the effect of porosity. The images clearly show that the pore size is positively correlated with both porosity and aggregate size. Additionally, the distributions of pore size and cement paste thickness can be described using a lognormal distribution function and a two-parameter Weibull function, respectively. Blockage analysis revealed that the blockages were primarily concentrated within the top 0-30 mm of the porous concrete surface. As the pore size increases, the blockage depth increases, and blockages in the 10-30 mm range are challenging to remove with high-pressure water jets. A degradation model for the permeability performance of aggregate porous concrete, considering blockage consolidation, was established using parameters such as the blockage accumulation per unit area, aggregate particle size, and concrete porosity. This model provides theoretical and data-based references for evaluating the service life of porous concrete.