Hybrid slag geopolymer composites with durable characteristics activated by cement kiln dust

• Published in: Construction & building materials 2019-12, Vol.228, p.116708, Article 116708
• Main Author: Khater, H.M.
• Format: Article
• Language: English
• Subjects: Cement dust; Durability; Electric arc furnace slag; Geopolymer; Sulfate
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2019.116708

•Production of environmentally friendly cementing materials for various building purposes.•Activation of industrial slag wastes using cement dust with high alkalis.•Uses of electric arc furnace resulted in better stability against sulfate attack up to 50%.•Produced geopolymer EAFS possess stability up to 12 month. The effect of sulfate solution on the geopolymer formed from different type of slag as arc slag (EAFS) and granulated blast furnace slag (GGBFS) as well as cement kiln dust (CKD) was studied. Activation was carried upon usage of 25% CKD, as it bears high alkali content that can initiate and propagate the polymerization process. The formed geopolymer composites were immersed in 5% MgSO4 solution to determine the stability upon sulfate attack. FTIR, XRD, SEM, compressive strength and water absorption analysis were utilized to examine the obtained geopolymer under sulfate attack. Results clarified an optimization of strength values by EAFS increase up to 50%, followed by lowering in strength with EAFS increase, possessing stability up to 12 months. Data elucidated a good stability and resistance of mix containing slag substitution by 50% EAFS and 25% GGBFS and resulted in further enhancement in both mechanical and micro-structural characteristics by increasing matrix compaction and cohesion than the non-immersed samples (28 days).