The mechanical strength, degree of hydration, and electrical resistivity of cement pastes modified with superabsorbent polymers

• Effect of SAPs was shown to be more pronounced at lower water/cement ratios.
• Capillary pore densification and macrovoid formation were shown to affect electrical resistivity.
• Strength decreases more notably when SAPs generate a large number of macrovoids.

This paper examines the effect of superabsorbent polymers (SAPs) with varied sizes and absorption behaviors on the mechanical strength, hydration and transport characteristics of cementitious materials. Mechanical strength was assessed using the compressive and flexural strength tests. Non-evaporable water content measurement was utilized to evaluate the degree of hydration of the cement pastes. The transport behavior of cement pastes was characterized using electrical resistivity measurement. It was shown that for the SAPs and mix designs used in this study, the incorporation of SAPs generally reduced the strength, especially in the cement pastes with a high density of macrovoids. The electrical resistivity of cement pastes with slow desorbing SAPs appeared to be influenced by two opposing effects of pore structure densification and macrovoid formation. It was observed that the influence of SAPs on the compressive strength and electrical resistivity of cement pastes was more noticeable at water/cement ratios of 0.35 and 0.4 than at 0.5.