Preparation of an Ester-Based Polymeric Hydration Temperature Rise Inhibitor and Its Action Mechanism on Cement Hydration

To address the thermal cracking induced by concentrated heat release during early cement hydration, a novel Ester-based Polymeric Hydration Temperature Rise Inhibitor (ETRI) was designed and synthesized in this study based on the slow hydrolysis property of ester functional groups. After its incorporation into cementitious materials, the influence of ETRI on the hydration kinetics and the microstructure of hardened paste was systematically investigated. The results demonstrate that ETRI effectively regulates the heat release profile of cement hydration by prolonging the induction period. Specifically, at a dosage of 1.5%, ETRI reduces the peak heat release rate by 70.32% and the 72 h cumulative heat release by 70.82%. Mechanistic investigation reveals that ETRI undergoes slow hydrolysis in the alkaline environment to generate carboxyl groups that complex with Ca2+; the resulting calcium carboxylate complexes then adsorb onto the surfaces of cement particles, thereby retarding the hydration heat release process. Furthermore, with ETRI dosages not exceeding 1.5%, the promoted later-age hydration yields more hydration products, which refine the pore structure and increase the harmless pore proportion to 53.97%, thereby achieving a synergistic improvement in both the microstructure and the late-age mechanical properties of the cementitious materials. Compared with conventional retarders, ETRI exhibits a stronger inhibitory effect on the heat release of cement hydration.