Investigation on the compressive strength and durability properties of alkali-activated slag mortar: Effect of superabsorbent polymer dosage and water content

Abstract

This paper presents the properties of alkali-activated slag (AAS) mortar additivated with a superabsorbent polymer (SAP) to improve its mechanical and durability properties. The effect of different dosages of SAP (0.0–0.3% with respect to the blast furnace slag weight) and different extra water additions on setting time, autogenous shrinkage, compressive strength, water permeability, frost resistance, heat of hydration, and porosity is presented and discussed. The results highlight the beneficial effect of adding SAP on the mechanical and durability properties of the proposed mixtures. Only at higher percentages of SAP and additional water occur performance drops due to excessive macro-porosity of the system. It is interesting to point out that, in contrast, shrinkage always decreases as the percentages of SAP addition and additional water increase, although it cannot be completely eliminated. Experimental evidence also highlights that significant benefits can be gained from using this material in harsh environments.

Keywords

• Internal curing
• Superabsorbent polymer
• Alkali-activated slag
• Shrinkage
• Durability