铝相对钙矾石生长调控及稳定性研究OA

Ettringite is the main hydration product of sulfate-based low-carbon cementitious materials and has a significant impact on the mechanical properties and durability of the materials.It is crucial to explore the formation and evolution process of ettringite.Aluminum phase is often used as a key component to regulate the growth of ettringite.Existing studies mostly focus on the improvement of the macroscopic performance of low-carbon cementitious materials by adding external aluminum phase,while the formation mechanism of ettringite by it still needs to be further improved.This paper synthesized ettringite using four types of aluminum phases,namely,crystalline aluminum chloride(AC),aluminum sulfate octadecahydrate(AS),polymeric aluminum sulfate(PAS),and sodium aluminate(NA),as raw materials,and investigated the influence of the type of aluminum phase on the growth behavior and stability of the synthesized ettringite.The results show that 60℃is the optimal synthesis temperature for ettringite formation,and the mass fraction of ettringite formed with AS participation is the highest,reaching 94.23%.Compared with other aluminum phases,the maximum weight loss temperature of ettringite formed with AS participation is 120.4℃,with the best thermal stability,more stable crystal structure,and a smaller variation in the aspect ratio,which is around 14.5.This study provides a theoretical foundation for the subsequent optimization design and performance improvement of low-carbon cementitious material systems.