Preparation and properties of expanded perlite-based paraffin phase change reinforced concrete

Phase change material (PCM) has poor mechanical properties compared to its good thermal properties. Research on phase change concrete mixed with silica fume and fly ash for mechanical compensation, so that it has both ideal thermal and mechanical properties. The compressive strength change rule of concrete with different PCM dosage is studied. The results show that the compressive strength of reinforced phase change concrete is notably enhanced compared to that of ordinary phase change concrete, particularly in groups with higher PCM content, where the reinforcement effect is even more pronounced. Further analysis of the reinforcing mechanism shows that silica fume synergistically improves the mechanical properties of high PCM-added concrete by filling the pores, optimizing the interfacial transition zone, and generating C-S-H gel, and fly ash synergistically improves the mechanical properties of high PCM-added concrete by secondary hydration and microaggregate effect.