Zhang De, Yang Zhijie, Kang Dong, Fang Chenyang, Jiao Yang, Mi Shizhong
School of Mining and Technology, Inner Mongolia University of Technology, Hohhot 010051, China.
The Key Laboratory of Green Development for Mineral Resources, Inner Mongolia University of Technology, Hohhot 010051, China.
Materials (Basel). 2022 Mar 20;15(6):2304. doi: 10.3390/ma15062304.
Calcium silicate slag (CSS) is used as a secondary solid waste produced by aluminum extraction technology from high alumina fly ash, and its resource utilization has always been a key issue to be solved. In this study, CSS was used to replace a portion of fly ash (FA) to prepare a new inorganic binder stabilized material for road base. The unconfined compressive strength (UCS), phase composition, microstructure, durability and performance index of the base of the test section of the CSS pavement base material were studied. The results showed that with the increase in CSS content, the UCS of pavement base materials gradually increased. Under standard curing conditions, the UCS increased 6.9017.24% after 7 days, and 7.9028.95% after 28 days. The main reason was that as the hydration time increased from 7 d to 28 d, the hydration products C-A-S-H gel and C-S-H gel increased, the [SiO] polymerization degree increased, the crystal type changed, and the structure denser, which supported the good development of mechanical strength of CSS pavement base material. In addition, the research has been successfully applied to a pilot test in Hohhot, China. The freeze-thaw resistance, water stability and UCS of the CSS pavement base material were tested to meet the requirements of Chinese road construction standards, indicating that the application of CSS in pavement base is feasible.
硅酸钙炉渣（CSS）是高铝粉煤灰提铝工艺产生的一种二次固体废物，其资源利用一直是亟待解决的关键问题。本研究采用CSS替代部分粉煤灰（FA）制备新型无机结合料稳定道路基层材料。对CSS路面基层材料试验段基层的无侧限抗压强度（UCS）、物相组成、微观结构、耐久性及性能指标进行了研究。结果表明，随着CSS含量的增加，路面基层材料的UCS逐渐增大。在标准养护条件下，7d后UCS提高了6.90%17.24%，28d后提高了7.90%28.95%。主要原因是随着水化时间从7d延长至28d，水化产物C-A-S-H凝胶和C-S-H凝胶增多，[SiO]聚合度提高，晶体类型发生变化，结构更加致密，有利于CSS路面基层材料力学强度的良好发展。此外，该研究已在中国呼和浩特成功应用于中试试验。对CSS路面基层材料的抗冻性、水稳定性和UCS进行测试，均满足中国道路建设标准要求，表明CSS在路面基层中的应用是可行的。
