| CHINESE MATERIALS CONFERENCE — ECO-MATERIALS |
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| Application Performances and Mechanism of Polycarboxylic Acid in Different Comb-bonded Structures in High-performance Concrete |
| LIU Xiao1, XU Qian1, LAI Guanghong1, GUAN Jianan1, XIA Chunlei2, WANG Ziming1, CUI Suping1
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1 College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124;
2 Beijing Municipal Engineering Research Institute, Beijing 100037 |
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Abstract The comb-type polycarboxylic acid has excellent architecture designability, providing the theoretical basis and technical support for the ecologicalization and high performance of green concrete. In this study, polyacrylic acid (PAA), hydroxymethoxy polyoxyethylene propylene glycol (HMPEPG) and amino methoxy polyoxyethylene propylene glycol (AMPEPG) were used as reactants based on the esterification and amidation reactions, and the two comb-type polycarboxylic acids (PCEs) which backbone and side chain were connected by ester bond and amide bond were synthesized, respectively. The measurements of Infrared spectroscopy (IR) and molecular weight proved the expected molecular structures. The application results showed that the PCE with ester linkage exhibited better initial fluidity of cement paste and early strength of concrete, and moreover, the PCE with amide linkage exhibited better fluidity retention of cement paste and slump flow of concrete. With respect to their different mechanism, the PCE with ester linkage behaved more stable adsorption behavior and stronger acceleration to hydration, whereas the PCE with amide linkage behaved lower surface tension and stronger ability in gas-liquid interface orientation. These two PCEs can be applied to the concretes with high early strength and high pumping requirements respectively, presenting a good promotion value and application prospect.
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Published: 21 December 2018
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2018, Vol. 32 
