Use of CO2 curing to enhance the properties of cold bonded lightweight aggregates (CBLAs) produced with concrete slurry waste (CSW) and fine incineration bottom ash (IBA)

Pei Tang; Dongxing Xuan; Hiu Wun Cheng; Chi Sun Poon; Daniel C W Tsang

doi:10.1016/j.jhazmat.2019.120951

Use of CO₂ curing to enhance the properties of cold bonded lightweight aggregates (CBLAs) produced with concrete slurry waste (CSW) and fine incineration bottom ash (IBA)

J Hazard Mater. 2020 Jan 5:381:120951. doi: 10.1016/j.jhazmat.2019.120951. Epub 2019 Jul 31.

Authors

Pei Tang¹, Dongxing Xuan², Hiu Wun Cheng², Chi Sun Poon³, Daniel C W Tsang²

Affiliations

¹ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. Electronic address: pei.tang@polyu.edu.hk.
² Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
³ Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. Electronic address: cecspoon@polyu.edu.hk.

PMID: 31416042
DOI: 10.1016/j.jhazmat.2019.120951

Abstract

In this study, concrete slurry waste (CSW) obtained from ready-mixed concrete plants was recycled as a fresh cementitious binder and used together with municipal solid waste incineration (MSWI) fine bottom ash (IBA) from waste-to-energy plants to produce cold bonded lightweight aggregates (CBLAs) by using a pelletizing technique. The influence of different curing methods on the properties of the produced CBLAs were experimentally investigated, including moist curing, steam curing, and accelerated CO₂ curing at 0.1 bar and flow-through CO₂ curing under ambient pressure. The results showed that CBLAs obtained by steam curing at 60 °C had the highest pellet strength, and the CO₂ cured samples had the lowest water absorption values. CO₂ curing with a pressure of 0.1 bar promoted a better pellet strength. The CO₂ curing method can sequestrate 3.5-4.1% (by mass of pellets) of CO₂, which can serve as a sustainable CO₂ sequestration process to produce CBLAs.

Keywords: Accelerated CO(2) curing; Cold bonded lightweight aggregates; Integral recycling; Solid wastes.

Publication types

Research Support, Non-U.S. Gov't