An LC3-type binder produced with marine clay and municipal waste incineration fly ash

Abstract

Marine clay and municipal waste incineration ash are two major wastes in Singapore. The low reactivity of marine clay and high chloride (Cl) content in incineration fly ash (IFA) limit their application as supplementary cementitious materials. In this study, these wastes are synergistically used to prepare an LC3-type binder. The compressive strength of the proposed binder is comparable to or higher than the OPC references at 7 and 28 days. Pore-filling AFm crystals are ubiquitous in the hardened paste, which are characterized as hemicarbo-AFm and (Cl-, CO32-)-AFm when IFA was and was not subjected to Cl-removal treatment, respectively. A significant conversion of AFt to AFm is observed during the first 28 days. The leaching of Cl and certain heavy metals are reduced compared with the case of IFA-OPC binary binder. This work broadens the concept of LC3 binder system, and may inspire circulation of wastes in Singapore for construction practice.