Title: Mechanism Study on the Slow-Release Effects of Polycarboxylate Superplasticizers with Different Functional Groups in Cement Pastes

Author(s): Sun Zhenping, Pang Min, Yang Haijing, Wu Lelin, Ge Haosheng, Shu Xuejun, Shu Doudou, Zhu Weigang, Luo Qiong

Publication: Symposium Paper

Volume: 354

Issue:

Appears on pages(s): 339-346

Keywords: polycarboxylate superplasticizers; slow-release; hydrolysis; flowability; ester groups

DOI: 10.14359/51736086

Date: 7/1/2022

Abstract:
The slow-release effects of polycarboxylate superplasticizers (PCEs) with different functional groups in cement pastes were investigated by the flowability of cement pastes as well as hydrolysis of PCEs and adsorption of PCEs. Results showed that the initial flowability of cement pastes had been decreased by PCEs with different ester groups but the time-dependent flowability of cement pastes with these PCEs had been partly improved by the slow release effects of ester groups in molecules of PCEs. Hydrolysis of PCEs had been increased by ester groups, which further resulted in the increasing adsorption amounts of PCEs and the activated slow-release effects of PCEs. The mechanism of the slow-release effects of PCEs with different ester groups was mainly due to various hydrolysis rates of ester groups which might further lead to differences of carboxyl groups to influence the adsorption amount of PCEs.