Effect of white mud on properties of alkali activated slag
Renjuan Sun (Shandong University)
Linglai Bu (Shandong University)
Hongzhi Zhang (Shandong University)
Yanhua Guan (Shandong University)
Chuanyi Ma (Shandong Hi-Speed Group)
Zhi Ge (Shandong University)
B. Šavija (TU Delft - Materials and Environment)
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
White mud is a solid waste from the papermaking industry, composed mainly of CaCO3 and residual alkali metal ions (such as Na+, Mg2+). In the current study, the feasibility of using white mud as partial replacement of slag in alkali activated materials is explored. The fluidity, setting time, autogenous shrinkage, mechanical properties, hydration products and microstructure of alkali activated slag containing different amount of white mud are studied. The results show that adding white mud reduces the fluidity of freshly mixed paste, setting time and autogenous shrinkage. The ions released from the white mud participate in the polymerization reaction, accelerate the hydration reaction in the early stage, and promotes the precipitation of Mg-Al and the formation of hydrotalcite. However, excessive quantities of white mud (above 15% of the binder) leads to the reduction of compressive strength. As the content of white mud is enhanced, the Ca/(Si + Al) ratio of the gel increases and the degree of polymerization is reduced. It has been shown that white mud has potential reactivity and can partially replace slag to prepare new alkali activated materials.