Hydration characteristics and kinetic analysis of polyacrylamide (PAM) anti-dispersion cement-based materials

Abstract

Through phase analysis and quantitative calculations of the hydration process, the inclusion of polyacrylamide (PAM) in Anti-dispersion Water Paste affects its hydration characteristics is discovered. Specifically, the presence of PAM reduces early reactivity while accelerating progress in the middle to late stages of hydration. By employing K-D hydration kinetic analysis, it is confirmed that the use of PAM results in the formation of a multi-nucleation homogeneous point system within the cement slurry. This system prolongs the NG (nucleation and growth) process time, increases the hydration degree during the transition from NG to I (induction) process, and inhibits the heterogeneous precipitation of hydration products. Consequently, the early hydration of cement is hindered. As the hydration reaction advances, the microstructure of the product under multi-nucleation points increases the specific surface area. This gradual breakthrough of the hydration threshold barrier shortens the duration of the phase boundary reaction process and reduces the hydration degree during the I and D (diffusion) processes. Consequently, the late-stage hydration rate is accelerated.