Research Information System
Construction and Building Materials, vol.506, 2026 (SCI-Expanded, Scopus)
Phase change materials (PCMs) offer strong potential for reducing building energy demand. This study aims to develop lightweight structural mortars with improved indoor thermo-regulation by incorporating a form-stable PCM (FSPCM). The FSPCM was produced by impregnating expanded vermiculite (EV) with n-octadecane at a 40 wt% ratio. The reference mortar was prepared using EV as a lightweight aggregate at 25 wt% relative to cement. To obtain thermally enhanced composites, this EV fraction was replaced with FSPCM at substitution levels of 25–100 %. All mixtures were characterized to evaluate their physical, mechanical, and thermal performance. The mixture completely replaced with FSPCM showed the most significant improvements, achieving a thermal conductivity of 0.456 W/mK, density of 1.07 g/cm³ , and compressive strength of 8.81 MPa. DSC analysis of the FSPCM revealed melting and solidification temperatures of 25.76 and 25.42 °C, with latent heats of 100.4 and 99.5 J/g. Thermo-regulation tests confirmed effective reduction in indoor temperature fluctuations. A preliminary cost–performance evaluation, based on unit material prices and experimentally observed thermal benefits, indicates that FSPCM-integrated mortars may provide favorable life-cycle economics despite higher initial material costs. In conclusion, the EV/n-OC composites demonstrate strong potential as sustainable and energy-efficient building materials.