Phase Change Materials in Concrete: A Review of Incorporation Methods, Effect on Mechanical and Thermal Properties, and Long-Term Performance

The construction industry faces increasing pressure to reduce energy consumption and improve the thermal resilience of infrastructure. While integrating phase change materials (PCMs) into concrete can significantly enhance thermal energy storage, it often compromises mechanical strength and durability. The central challenge is establishing whether the thermal benefits outweigh these structural trade-offs. This paper provides a critical review of the mechanical, thermal, and long-term durability performance of PCM-concrete composites. Beyond standard material properties, this review highlights often-overlooked applications, specifically the use of PCMs to reduce thermal gradients in pavements, thereby mitigating slab curling and thermal cracking. Furthermore, we evaluate the essential role of numerical modeling as a design tool to optimize PCM dosage and location without the need for extensive physical prototyping. This synthesis aims to bridge the gap between material science and structural engineering, providing practitioners with the design strategies needed to transition PCM technology from laboratory research to scalable construction applications.