Preparation, Performance, and Environmental Deterioration of Cement-Based Self-Insulating Wall Materials

DOI: https://doi.org/10.62517/jcte.202606302

Author(s)

Xianliang Yin1, Liang Zhao1,*, Liping Tian2, Xiaolong Li1, Qiuwang Jiang1

Affiliation(s)

1College of Civil Engineering and Architecture, Yangtze Normal University, Chongqing, China 2Shaanxi Province Design and Research Institute of Building Materials Industry Co., Ltd., Xi’an, Shaanxi, China *Corresponding Author

Abstract

This study focuses on cement-based self-insulating wall materials, conducting experimental research on pore structure control, optimization of fundamental properties, and performance degradation under high humidity and thermal conditions. Using 42.5-grade Portland cement as the primary binder, modified sodium rosinate as the foaming agent, and waste engine oil as the foam stabilizer, cement-based self-insulating wall materials with varying water-to-cement ratios and pore sizes were prepared via physical foaming. The true density, apparent density, water absorption rate, closed-pore ratio, compressive strength, and microstructure were tested. Subsequently, a coupled high-temperature-high-humidity environment (40 °C, 80% RH) was applied to analyze the effects of temperature and humidity on the material's thermal conductivity and mechanical properties. Results indicate that both water-to-cement ratio and pore size significantly influence the pore structure and macroscopic performance. Excessively high water-to-cement ratios increase interconnected pores and visible voids, leading to higher water absorption, lower closed-pore content, and reduced material strength. Conversely, excessively large pore sizes tend to cause thinning of pore walls, pore interconnection, and structural delamination, which hinder the simultaneous improvement of insulation and mechanical performance. When the water-to-cement ratio is 0.50 and pore size ranges from 1.0 to 2.5 mm, the material exhibits optimal overall performance: a closed-pore ratio of 34.59%, water absorption of 11.30%, compressive strength of 6.15 MPa, a thermal conductivity of 0.087 W·m⁻¹·K⁻¹ in dry condition, and 0.099 W·m⁻¹·K⁻¹ after exposure to high humidity and heat—representing a degradation rate of only 13.79%. In contrast, samples with high water-to-cement ratios and large pores show significantly increased thermal conductivity under humid-heat conditions, indicating greater environmental sensitivity. The study demonstrates that an appropriate water-to-cement ratio combined with moderate pore size promotes a higher closed-pore ratio and more stable pore structure, enabling coordinated optimization of lightweight, thermal insulation, mechanical strength, and resistance to moisture-heat degradation in cement-based self-insulating wall materials.

Keywords

Cement-Based Self-Insulating Wall Materials; Physical Foaming; Water–Cement Ratio; Pore Size; Coupled High Temperature and Humidity Environment

References

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