Work

Mechanical properties and Freeze-Thaw durability of concrete modified with microencapsulated phase change materials

Year: 2025

Type: article

Abstract: Microencapsulated phase change materials (mPCM) emerge as sustainable thermal energy regulation additives for enhancing concrete durability in cold climates. This investigation systematically evaluates the dose-dependent effects of mPCM incorporation (0-12% cement replacement) on mechanical-strength development and freeze-thaw resistance through comprehensive mechanical testing, 100-cycle accelerated freeze-thaw evaluations, and quantitative microstructural analysis. The experimental findings reveal a critical biphasic relationship: Optimal 6% mPCM addition significantly enhances mechanical performance with 8.90%, 19.23%, and 30.72% improvements in ompressive strength, flexural strength, and splitting tensile strength versus control, while maintaining exceptional frost durability (1.6% mass loss and < 15% strength degradation post-freeze-thaw). Microstructural analysis reveals that 6% mPCM optimizes the pore structure of concrete by reducing pore size and moderately increasing porosity, thereby enhancing freeze-thaw durability. Beyond the critical 9% threshold, the concrete matrix becomes loose, leading to a decline in overall strength. The established dosage-property correlation provides practical guidance for cold-region concrete design, demonstrating that 6% mPCM incorporation achieves synergistic enhancement of load-bearing capacity and phase-change-enabled thermal stress mitigation.

Source: Scientific Reports

DOI: 10.1038/s41598-025-11371-6