Architectural Engineering
LIU Jianping, HU Ziyang, LIU Peng, WANG Shenyu, WANG Yusheng, ZHANG Wenxin, LI Xiaohui, PANG Shuyun
In order to solve the problem of low comprehensive utilization rate for steel slag and other bulk industrial solid wastes, silica fume (SF) was selected as reinforcing agent and soda residue (SR) was used as partial activator, to activate steel slag (SS) and granulated blast furnace slag (GBFS) for the preparation of alkali-activated steel slag/furnace slag cementitious materials. Basic tests and researches, such as compressive strength, flexural strength, drying shrinkage, freeze-thaw cycle resistance, sulfate resistance and SEM analysis were carried out. The results show that the addition of SR and SF can significantly improve the mechanical properties and durability of cementitious materials. The 28 d compressive strength and flexural strength of alkali-activated steel slag/furnace slag cementitious materials under the optimal ratio are 36.20 MPa and 13.29 MPa, respectively. After 50 freeze-thaw cycles, the mass loss rate is 1.73%; after soaking in 5% Na2SO4 for 28 d, the strength loss rate is 2.98%, meeting the 32.5-grade requirements for ordinary slag cement.