| INORGANIC MATERIALS AND CERAMIC MATRIX COMPOSITES |
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| Synthesis and Mechanism of Polycarboxylate Superplasticizer Based on the Inhibition of Negative Effects of Clay |
| LIU Xiao, LAI Guanghong, XU Qian, GUAN Jianan, WANG Ziming, CUI Suping, LAN Mingzhang
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| College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 |
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Abstract Clay attached in concrete has deterioration effect on the application of high-performance concrete. In this paper, the improvement of polycarboxylate superplasticizer (PCE) synthesized based on the molecular calculation on the negative effect of clay was investigated, and the mechanism was revealed by adsorption, thermal gravimetric (TG) and X-ray diffraction (XRD) measurements. The adsorbed substance between interlayers of clay was side chains rather than the whole PCE, and thus a spatial PCE with large dimension was synthesized followed by 1H nuclear magnetic resonance (1H NMR) and gel permeation chromatography (GPC) characterizations. The results showed that in existence of clay, the fluidities of cement pastes containing this PCE increased by 22.2%—35.7%, but also for the 1 h slump of concrete. This is ascribed to its large-sized structure which can generate steric hindrance effect, and thus its side chains can be prevented from being adsorbed in between interlayers of clay to ensure good dispersing effectiveness, presenting an inhibition of negative effect of clay.
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Published: 21 December 2018
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2018, Vol. 32 
