Effects of A12O3 on the hydration activity of municipal solid waste incinerator fly ash slag

• Published in: Cement and concrete research 2004-04, Vol.34 (4), p.587-592
• Main Authors: Lin, K L, Wang, K S, Tzeng, B Y, Wang, N F, Lin, C Y
• Format: Article
• Language: English
• ISSN: 0008-8846
• DOI: 10.1016/j.cemconres.2003.09.015

This study investigates the effects of slag composition on the hydration activity of slag-blended cement (SBC) pastes. Synthetic slag samples were prepared by melting Al2O3-modified, municipal solid-waste incinerator (MSWI) fly ash. In addition to the original slag (containing 25.0% CaO and 17% Al2O3), two other synthetic slag types, A1 and A2 slag, were prepared, having a 15% or 5% Al2O3 content, respectively. These synthetic slags were blended with ordinary Portland cement (OPC) at weight ratios ranging from 10% to 40%. The results indicate that the incorporation of 10% A1 slag tended to enhance the degree of hydration in SBC pastes during the early ages (3-28 days), but at later ages, significant difference in the degree of hydration between the OPC and SBC pastes with 10% A1 slag was not observed. The tendency of the 10% A2 slag case was similar, but with a limited enhancement during the early ages (3-28 days). However, samples that incorporated the Al2O3-modified slag (AMS) showed decreased degrees of hydration. The degree of hydration of the 40% blend ratio sample decreased significantly.