稻壳灰混凝土耐久性研究综述

[Objective] Rice husk ash (RHA), as bulk agricultural waste generated during rice processing, has been increasing in annual production with the growth of global rice consumption. The use of RHA as a supplementary cementitious material for concrete can significantly reduce carbon emissions during concrete production by replacing part of cement and also effectively improve the durability and mechanical properties of concrete, which is in line with the demand for sustainable development of the construction industry. However, the durability of RHA concrete is influenced by a number of factors such as particle size distribution, concrete mix design, and curing conditions. Existing studies are fragmented and lack a systematic performance evaluation framework and optimization design strategy. Therefore, this study aims to review the durability of RHA concrete, analyze the mechanism and influencing factors of its deterioration resistance, and provide theoretical support for the development of application standards and breakthroughs in promotion bottlenecks, so as to promote its wide application in green building materials. [Methods] The focus of this study was the durability of RHA concrete, and the research progress on its shrinkage, carbonation resistance, chloride penetration resistance, acid resistance, freeze-thaw cycle resistance, and fire resistance was systematically investigated. The research included the analysis of the physicochemical properties of RHA (e. g., silica content, particle size, and volcanic ash activity) and investigation of the effects of different RHA contents and treatments (e. g., chemical activation, heat treatment, and wet curing) on the properties of concrete. In addition, the synergistic effects of RHA with other mineral admixtures ( e. g., coal fly ash, slag, and metakaolin) and its optimization effect on durability were explored. [Results] After the various aspects of performances in the field of durability were sorted out and summarized, the corresponding research content and key technologies were summarized. It is found that RHA concrete has significant improvements in shrinkage inhibition, carbonation resistance, chloride penetration resistance, acid corrosion resistance, freeze-thaw cycle durability, and fire resistance. In addition, the systematic study concludes that RHA can achieve multi-dimensional enhancement of concrete durability performance, which aligns with the development needs of sustainable building materials. However, the engineering application of RHA concrete still faces multiple challenges: the quality difference of RHA due to the difference in raw material sources requires the establishment of strict control standards for activity index and particle size distribution; the sensitivity of alkali-silica reaction requires the precise control of RHA dosage and alkali content; the long wet curing period increases construction and time costs significantly. [Conclusion] Future research should focus on standardization of RHA quality, synergies with other mineral admixtures, innovative treatment methods, and monitoring of long-term performance to promote the widespread use of RHA concrete in construction and reduce the environmental impact of conventional cement.