Reuse of drinking water treatment sludge in mortar as substitutions of both fly ash and sand based on two treatment methods. (29th March 2021)

• Record Type: Journal Article
• Authors: Li, Danda; Zhuge, Yan; Liu, Yue; Pham, Phuong Ngoc; Zhang, Chunyu; Duan, Weiwei; Ma, Xing
• Is Part Of: Construction & building materials. Volume 277(2021)
• Publication Date: 2021-03-29
• Subjects: Drinking water treatment sludge (DWTS) -- Treatment methods -- Heat-treatment -- NaOH-treatment -- Cementing efficiency factor (CEF); Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2021.122330
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: To replace fly ash and sand in mortar mix using drinking water treatment sludge (DWTS). To investigate the effect of both heat-treatment and NaOH-treatment methods. To analyze cementing efficiency factor (CEF) for fly ash replacement. To investigate 7-day to 56-day strength development. Abstract: In this paper, attempts were made to employ both heat-treated and sodium hydroxide (NaOH) treated drinking water treatment sludge (DWTS) as replacement of both fly ash and silica sand at varied substitution ratios in mortar mixes. For fly ash replacement, the heat treatment method results in improved compressive strength with up to 15% replacement ratio and the NaOH treatment method results in higher compressive strength with substitution ratios of up to 10% compared with reference samples. For sand replacement, the replacement ratio associated with improved mortar compressive strength is limited to 5% by weight for both treatment methods, however, heat-treated DWTS mixes showed higher strength than NaOH-treated mixes at the same substitution ratios. Cementing efficiency factor (CEF) for fly ash replacement mixes were analysed and results showed higher CEF with increased DWTS substitution ratio. Considering both the compressive strength and the micro-structural analysis results, treatment of DWTS subjected to evaluated temperature produced better performance mortar than that of NaOH-treated method.