The influence of superabsorbent polymer on the properties of alkali-activated slag pastes

•SAP showed higher absorption in extracted pore solution from AAS pastes than PC paste.•Desorption of hydrogel was delayed in AAS paste activated with Na2CO3 compared to AAS paste activated with NaOH or PC paste.•Addition of SAP was effective to reduce autogenous shrinkage in AAS pastes and PC paste. This paper discusses the interaction between superabsorbent polymer (SAP) and alkali-activated slag pastes and the influence of SAP on the properties of the pastes. SAP showed higher absorption in pore solutions extracted from alkali-activated slag pastes compared to that extracted from portland cement paste. Hydrogel desorption in alkali-activated slag matrix activated with Na2CO3 was noticeably delayed compared to alkali-activated slag matrix activated with NaOH matrix or portland cement matrix; this is attributed to a significant delay in the solid skeleton development in this matrix. Addition of SAP was shown to be effective in reducing autogenous shrinkage in alkali-activated slag pastes. A general reduction in compressive strength and electrical resistivity was observed in alkali-activated slag pastes when SAP was added; macrovoid formation and increased overall water/binder are possible reasons for this reduction, respectively.