Abstract:
A series of slow-release polycarboxylate superplasticizer (PCE) were prepared under the oxidation-reduction system, using hydroxyethyl acrylate (HEA), hydroxypropyl acrylate (HPA), dimethyl itaconate (DEI) and dimethyl fumarate (DMF) as functional small monomers respectively and acrylic acid and methallyl Polyoxyethy-lene ether (HPEG) as the main raw material. The structure of the polymers was characterized with FTIR and
1H NMR spectroscopy. The maximum fluidity reached by the synthetic superplasticizer at different intervals was determined according to the comparison of the fluidity of the cement paste, the effect of the different ester monomers on the slow release of the polycarboxylate superplasticizer was investigated, and the Zeta potential of the cement paste and the adsorption behavior of PCE were tested. The results showed that the slow-release effect of dimethyl itaconate was better than that of hydroxyethyl and hydroxypropyl ester, and the fluidity of the cement slurry was better than that of hydroxyethyl and hydroxypropyl esters. From 190 mm to 255 mm within 2 h, the adsorption time and fluidity retention time of PCE on the cement surface was greatly prolonged. The material has good application prospects for high fluidity and long-term maintenance of concrete configurations.