Effects of curing temperature and superabsorbent polymers on hydration of early-age cement paste containing a CaO-based expansive additive

摘要

The early-age shrinkage can easily result in crack of concrete in the early age, which seriously affects the durability of concrete. The CaO-based expansion additive is a normally used and effective material for the shrinkage compensation and the reduction of early-age crack risk in concrete. The hydration is a factor that significantly influences the mechanical and durability properties of concrete, and the study on the hydration of the cement paste containing a CaO-based expansive additive under different curing temperature and with superabsorbent polymers addition is lacking. In this study, tests were conducted using the low-field nuclear magnetic resonance to assess the effect of curing temperature and superabsorbent polymers on the hydration of early-age cement paste containing a CaO-based expansion additive. The experimental results show that the incorporation of CaO-based expansive additive can promote the hydration of cement paste, and 2% dosage of CaO-based expansive additive has a better promotion than that of 3% dosage. High curing temperature can effectively accelerate the hydration of cement paste containing the CaO-based expansion additive. In addition, superabsorbent polymers can also effectively promote hydration.