Influences of Paraffin-Based Phase Change Material on Soil Engineering Properties
Donghai Liu, Jiaqi Yang
Abstract
Paraffin-based phase change materials (PPCMs) have been recognized as a potential tool to regulate soil temperature and reduce the freeze–thaw impact on soil. However, as a new filling material for geotechnical structures, such as dam core walls, the engineering applicability of PPCM-mixed soil (PS) needs to be further studied. In this paper, the influences of PPCM on the soil engineering properties (i.e., compaction characteristics, consolidation properties, mechanical behaviors, and permeability) and the PPCM leakage behavior were studied through a series of laboratory experiments. The results showed that the addition of PPCM results in an obvious decrease in the maximum dry density and optimum water content, a slight change in the compression coefficient, a significant reduction of the plasticity and cohesion, and an enhancement of the friction angle and impermeability. In addition, the PPCM in PS specimens will leak under the constant hydraulic gradient or vacuum saturation, and the leaked mass is positively related to the initial PPCM content. The PS specimens after 64-day seepage will still have a good impermeability. This paper is an important prerequisite for the practical applications of PS and provides a basis for its performance improvement.