A ternary blended binder incorporating alum sludge to efficiently resist alkali-silica reaction of recycled glass aggregates. (15th May 2022)

• Record Type: Journal Article
• Authors: Duan, Weiwei; Zhuge, Yan; Pham, Phuong Ngoc; Liu, Yue; Kitipornchai, Sritawat
• Is Part Of: Journal of cleaner production. Volume 349(2022)
• Publication Date: 2022-05-15
• Subjects: Alkali-silica reaction mitigation -- Drinking water treatment sludge -- Ground granulated blast furnace slag -- Supplementary cementitious materials -- Recycled glass aggregates -- Value-added recycling; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2022.131415
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: Recycled glass has been widely used as aggregates in cement-based materials. However, it may lead to a severe alkali-silica reaction (ASR) due to high reactive silica content in glass, causing cracks and failures in concrete structures. Our previous research indicated that utilization of alum-based drinking water treatment sludge (DWTS) as partial cement replacement could mitigate ASR. However, such mitigation only occurred when a high volume of DWTS was used and resulted in significant mechanical property deterioration. This study developed ternary blends containing ground granulated blast furnace slag (GGBFS) and DWTS content to overcome the strength loss. Up to 30% of the cement were replaced with DWTS and GGBFS at a mass ratio of 1:1. The results showed that the mortar made with the ternary blends had considerable compressive strength (37 MPa) compared with reference (34 MPa) when 30% cement by mass was replaced, and this replacement proportion could effectively control the ASR expansion under 0.1% in samples. The microstructural analysis was conducted using X-ray diffraction (XRD) patterns, X-ray fluorescence (XRF), and backscattered electron (BSE) coupled with energy-dispersive X-ray spectroscopy (EDS) techniques. The results indicated that the Al in the DWTS could limit the precipitation of the detrimental ASR gels by promoting the generation of calcium aluminum silicate hydrate (C-A-S-H), binding alkaline and preventing ASR gels from transforming into low-flowable gels. Graphical abstract: Image 1 Highlights: Develop a ternary blended mortar containing drinking water treatment sludge and slag. The ternary blended mortar can mitigate the strength loss caused by cement dilution. Al in the sludge had essential roles in mitigating alkali-silica reaction (ASR). 30% cement replacement in the ternary blended mortar can prevent ASR induced damage. Microstructural analysis revealed two locations of ASR gels with different Ca/Si.