Salt-thermally modified zeolite powder mortar: synergistic optimization of humidity regulation and mechanical strength

This study integrated inorganic salt modification and thermal treatment to optimize the pore structure of zeolite powder for enhancing its humidity regulation performance. The treatment method using 25% NaCl solution combined with heat treatment at 200℃ for 1 hour significantly enhanced the moisture adsorption and desorption capacities of natural zeolite powder, with the maximum moisture adsorption and desorption capacities increased by 6.4-fold and 7.4-fold, respectively. Additionally, the study investigated the effects of different dosages (0%-50%) of zeolite powder on the humidity regulation performance of mortar, and found that the moisture adsorption and desorption performance of the mortar increased with the increase of zeolite powder dosage, while the compressive and flexural strengths were affected. The test results showed that when the zeolite content was 50%, the moisture adsorption capacity increased by 19.5%, and the moisture desorption capacity increased by 46.8%. While modified zeolite powder mortar improved the humidity regulation performance, it also affected the mechanical properties of the mortar, especially in terms of compressive strength, which reached a peak of 22.9 MPa when the zeolite content was 10%, whereas the flexural strength gradually decreased with the increase of zeolite content, decreasing by 49.0% when the zeolite content was 50%. This study attempts to provide some technical ideas for the application of zeolite powder in the field of humidity regulation materials, and exploratorily proposes a low-cost and sustainable solution for humidity control in building envelopes. Future research can further focus on the influence rules of different modification conditions on the performance of zeolite powder and its application potential in practical complex environments.