TY - EJOU AU - Chen, Yong AU - Huang, Yinghao AU - Wu, Min TI - Fly Ash/Paraffin Composite Phase Change Material Used to Treat Thermal and Mechanical Properties of Expansive Soil in Cold Regions T2 - Journal of Renewable Materials PY - 2022 VL - 10 IS - 4 SN - 2164-6341 AB - Phase change materials (PCMs) can store large amounts of energy in latent heat and release it during phase changes, which could be used to improve the freeze-thaw performance of soil. The composite phase change material was prepared with paraffin as the PCM and 8% Class C fly ash (CFA) as the supporting material. Laboratory tests were conducted to reveal the influence of phase change paraffin composite Class C fly ash (CFA-PCM) on the thermal properties, volume changes and mechanical properties of expansive soil. The results show that PCM failed to establish a good improvement effect due to leakage. CFA can effectively adsorb phase change materials, and the two have good compatibility. CFA-PCM reduces the volume change and strength attenuation of the soil, and 8 wt.% PCM is the optimal content. CFA-PCM turns the phase change latent heat down of the soil and improves its thermal stability. CFA-PCM makes the impact small of freeze-thaw on soil pore structure damage and improves soil volume change and mechanical properties on a macroscopic scale. In addition, CFA-8 wt.% PCM treated expansive soil has apparent advantages in resisting repeated freeze-thaw cycles, providing a reference for actual engineering design. KW - Composite phase change material; freeze-thaw performance; expansive soil; thermal properties; mechanical properties DO - 10.32604/jrm.2022.018856