Wang Jiawei, Li Ting, Wang Jinbang, Zhang Chong, Zhang Xiuzhi, Duan Guangbin
School of Materials Science & Engineering, University of Jinan, Jinan 250022, China.
China Communications Construction Group Second Engineering Co., Ltd., Jinan 250022, China.
Materials (Basel). 2025 Mar 10;18(6):1228. doi: 10.3390/ma18061228.
Supersulfate cement (SSC) has received significant attention in the construction industry due to its extensive utilization of solid wastes and low carbon emissions. However, the low carbonation resistance and early strength of SSC greatly restricted its application, which was attributed to early insufficient alkalinity and slow hydration. Facilitating early hydration alkalinity is critical to promote early hydration and improve early performance for SSC. Thus, sodium aluminate (SA), an admixture with concentrations ranging from 0% to 4%, was adopted to enhance early alkalinity and investigate its impact on the initial hydration process. The results indicated that incorporating SA into SSC enhances its early performance by balancing high alkalinity and AFt stability. The addition of 2% SA accelerates hydration procession, reducing initial and final setting times by 76% and 42%, respectively, while increasing viscosity by 50% for improved structural stability. At 2% SA, 1-day and 7-day compressive strengths rose from 3.7 MPa to 8.4 MPa and from 15.1 MPa to 18.5 MPa, respectively, representing gains of 127% and 22.5%, which were facilitated by accelerated GGBFS dissolution and needle-like AFt formation, which densifies the crystal-gel network microstructure.
过硫酸盐水泥（SSC）因其对固体废弃物的大量利用和低碳排放而在建筑行业受到了广泛关注。然而，SSC的抗碳化性低和早期强度低极大地限制了其应用，这归因于早期碱度不足和水化缓慢。促进早期水合碱度对于促进SSC的早期水化和改善早期性能至关重要。因此，采用浓度范围为0%至4%的铝酸钠（SA）作为外加剂来提高早期碱度，并研究其对初始水化过程的影响。结果表明，将SA掺入SSC中可通过平衡高碱度和AFt稳定性来提高其早期性能。添加2%的SA可加速水化进程，使初凝和终凝时间分别减少76%和42%，同时粘度增加50%以提高结构稳定性。在2%的SA含量下，1天和7天的抗压强度分别从3.7MPa提高到8.4MPa和从15.1MPa提高到18.5MPa，增幅分别为127%和22.5%，这得益于加速的粒化高炉矿渣（GGBFS）溶解和针状AFt的形成，从而使晶体-凝胶网络微观结构致密化。
