Experimental Study on the Water Absorption and Drainage Performance of Capillary Water‐Conducting Materials

Moisture plays a crucial role in the manifestation of structural failures in cold‐region highway engineering. The implementation of capillary drainage materials serves as an effective strategy to mitigate moisture accumulation within subgrade soil. In this study, seven fabrics exhibiting capillary drainage properties were selected for free absorption and drainage performance tests, alongside drainage experiments in unsaturated soils, to benchmark their efficacy against conventional geotextiles. This study aims to elucidate the fundamental mechanisms governing the water absorption and drainage performance of these materials. The findings suggest that capillary drainage materials exhibit superior water absorption and evaporation characteristics compared to conventional geotextiles, with COOLPASS achieving the highest absorption capacity and COOLMAX demonstrating the most efficient evaporation performance. A comprehensive analysis of the drainage performance of these materials was conducted using the Mantel test and the random forest algorithm. Under varying moisture conditions, it is advisable to holistically consider the specifications and exposure area of capillary drainage materials to optimize their drainage performance in soil.