Balancing thermal insulation and mechanical performance in aerogel insulating mortar through synergistic cement-HPMC regulation

This study develops a synergistically regulated aerogel insulating mortar (AIM) by integrating aerogel-modified expanded perlite, hollow glass microspheres, and HPMC. Response surface methodology (RSM) quantifies the coupled effects of cement content and HPMC dosage on dry density, thermal conductivity, and compressive strength. The optimized formulation (5.293 g cement, 8.0 g HPMC) achieves a dry density of 211.8 kg/m 3 , thermal conductivity of 60.2 mW/(m·K), and compressive strength of ~0.50 MPa. Subsequent curing/drying pathway regulation further reduces thermal conductivity to 48.56 mW/(m·K). Microstructural analyses reveal that multiscale pore redistribution and interfacial modification jointly weaken solid-phase heat transfer while maintaining a functional load-bearing skeleton. This work provides a quantitative formulation-processing-microstructure framework for designing low-density AIM with balanced thermal-mechanical performance for energy-efficient building envelopes.