Chloride resistance of concrete containing nanoparticle-modified polymer cementitious coatings

• DOI: 10.1016/j.conbuildmat.2021.123736
• Publication Date: 2021-06-21T17:34:13Z
• Authors: Guo Li; Yi Ding; Tianyu Gao; Yiming Qin; Yajun Lv; Kejin Wang
• Keywords: Cementitious; Polymer Concrete

Abstract To improve the chloride resistance of traditional polymer-modified cementitious (PMC) coating, a novel nano-PMC coating was synthesized through incorporation of nano-SiO2 or nano-TiO2 suspensions into acrylic emulsion. Water absorption ratios, Coulomb electric fluxes, and chloride diffusion coefficients of coated concrete at different ages were tested. In addition, the micromorphology and pore structures of the nano-PMC coatings were investigated through scanning electronic microscopy and mercury intrusion porosimetry. Results indicate that the application of nano-SiO2 or nano-TiO2 particles in PMC coating can fully play the filling effects, refine the large micropores in coating and reduce its porosity. Thus, the waterproofing and chloride resistance of coated concrete are substantially enhanced. As a result, the service lives of concrete with nano-PMC coatings can be remarkably prolonged. The service lives of coated concrete against chloride attack can be lengthened by 7.1 times or 2.8 times 0.5% nano-SiO2 or nano-TiO2 are added into the PMC coating, respectively.