Lin Yonghui, Xu Dongqiang, Zhao Xianhui
School of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, China.
Department of Development and Domestic Cooperation, Hebei Normal University for Nationalities, Chengde 067000, China.
Materials (Basel). 2021 May 27;14(11):2883. doi: 10.3390/ma14112883.
Soda residue (SR), an industrial solid waste, pollutes the environment due to its high alkalinity and chloride ion content. SR can be used as an alkali activator of ground granulated blast furnace slag (GGBFS). This study investigated the effects of four types of SR-activated GGBFS cementitious materials (pastes) with different mass ratios of SR to GGBFS (8:92, 16:84, 24:76, 34:68) on the physical properties, mechanical strength, and chloride binding capacity. The hydration mechanism of the pastes was also studied. Results showed that with the increasing addition of SR, the density of the pastes decreased, and more white aggregates of SR appeared causing the increase of water absorption and porosity of the pastes. The pastes with 16% SR addition had the maximum compressive strength (34.1 MPa, 28 d), so the optimum proportion of SR addition in the pastes was 16%. With the increases of SR addition, the amount of chloride element in the initial pastes increases. When the proportion of SR addition is 8%, the mass percentage of free chloride ion in the pastes at 28 d is 0.13%. The main hydration products of the pastes were C-S-H gels, ettringite, and Friedel's salt, and the amount of ettringite varied with the amount of SR addition and curing time.
碱渣（SR）作为一种工业固体废物，因其高碱度和氯离子含量而污染环境。碱渣可作为粒化高炉矿渣（GGBFS）的碱激发剂。本研究考察了四种不同碱渣与粒化高炉矿渣质量比（8:92、16:84、24:76、34:68）的碱渣激发粒化高炉矿渣胶凝材料（浆体）对其物理性能、力学强度和氯离子结合能力的影响。还研究了浆体的水化机理。结果表明，随着碱渣掺量的增加，浆体密度降低，碱渣白色团聚物增多，导致浆体吸水率和孔隙率增加。碱渣掺量为16%的浆体抗压强度最高（28 d时为34.1 MPa），因此浆体中碱渣的最佳掺量为16%。随着碱渣掺量的增加，初始浆体中氯元素含量增加。当碱渣掺量为8%时，28 d时浆体中游离氯离子的质量百分比为0.13%。浆体的主要水化产物为C-S-H凝胶、钙矾石和Friedel盐，钙矾石的量随碱渣掺量和养护时间的变化而变化。
