Boosting the performance of low-carbon alkali activated slag with APEG PCEs: a comparison with ordinary Portland cement

Abstract

This study focused on investigating the dispersing effectiveness of polycarboxylate (PCE) superplasticizers with different carboxylate groups in two binder systems: Alkali-activated Slag (AAS) and Ordinary Portland Cement (OPC). Two α-allyl-ω-hydroxy poly (ethylene glycol) ether (APEG) PCE copolymers were prepared from acrylic acid (AA) or maleic anhydride (MA) separately. Performance test results in AAS revealed that MA-7APEG polymer exhibited much stronger dispersing efficiency than AA-7APEG2, despite both PCE polymers having the same anionicity and comparable molecular weight. This difference in effectiveness can be attributed to the stronger calcium binding capacity of the MA-7APEG polymer, as determined through anionic charge measurements and potential titration analysis. The study highlights the importance of considering the properties of the carboxylate groups in the design of effective PCE superplasticizers for use in different binder systems.