Affiliations 

  • 1 College of Civil Engineering, Hunan University, Changsha 410082, Hunan, China
  • 2 College of Civil Engineering, Hunan University, Changsha 410082, Hunan, China. Electronic address: tcling611@yahoo.com
  • 3 Department of Civil Engineering, Faculty of Engineering, Universiti Malaya, Kuala Lumpur 50603, Malaysia
J Hazard Mater, 2022 02 15;424(Pt B):127457.
PMID: 34653858 DOI: 10.1016/j.jhazmat.2021.127457

Abstract

In this study, municipal solid waste incineration fly ash (MSWIFA) was pretreated with CO2 via slurry carbonation (SC) and dry carbonation coupled with subsequent water washing (DCW). Both the treated MSWIFAs were then used as cement replacement in cement pastes by weight of 10%, 20% and 30% to investigate the influence on hydration mechanisms, physico-mechanical characteristics and leaching properties. The results showed that carbonates formed on the surface of SC-MSWIFA particles were finer (primarily 20-50 nm calcite) than those from the corresponding DCW-MSWIFA (mostly 130-200 nm vaterite). Hence, SC-MSWIFA blended cement pastes led to shorter setting time and higher early compressive strength than the DCW-MSWIFA pastes. In contrast, the presence of vaterite-rich DCW-MSWIFA in the blended cement pastes could accelerate the cement hydration after 24 h. Both the CO2-pretreated MSWIFA can replace cement up to 30% without sacrificing the long-term strength and mechanical properties of cement pastes, demonstrating excellent performance as a supplementary cementitious material. Moreover, volume stability in terms of expansion and lead leaching of CO2-pretreated MSWIFA cement pastes were far below the regulatory limits.

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.