Enhancing carbonation and chloride resistance of autoclaved concrete by incorporating nano-CaCO3

File

2020-WangKejin-EnhancingCarbonation.pdf (2.37 MB)

Date

2020-10-20

Authors

Wang, Kejin
Zhuang, Zhang
Lv, Yajun
Hui, David

Publisher

de Gruyter

Altmetrics

Authors

Wang, Kejin

Person

Professor

Organizational Units

Civil, Construction and Environmental Engineering

Organizational Unit

Department

Civil, Construction and Environmental Engineering

Abstract

Three nano-CaCO3 (NC) replacement levels of 1, 2, and 3% (by weight of cement) were utilized in autoclaved concrete. The accelerated carbonation depth and Coulomb electric fluxes of the hardened concrete were tested periodically at the ages of 28, 90, 180, and 300 days. In addition, X-ray diffraction, thermogravimetry, and mercury intrusion porosimetry were also performed to study changes in the hydration products of cement and microscopic pore structure of concrete under autoclave curing. Results indicated that a suitable level of NC replacement exerts filling and accelerating effects, promotes the generation of cement hydration products, reduces porosity, and refines the micropores of autoclaved concrete. These effects substantially enhanced the carbonation and chloride resistance of the autoclaved concrete and endowed the material with resistances approaching or exceeding that of standard cured concrete. Among the three NC replacement ratios, the 3% NC replacement was the optimal dosage for improving the long-term carbonation and chloride resistance of concrete.

Comments

This is a manuscript of an article published as Li, Guo, Zheng Zhuang, Yajun Lv, Kejin Wang, and David Hui. "Enhancing carbonation and chloride resistance of autoclaved concrete by incorporating nano-CaCO3." Nanotechnology Reviews 9, no. 1 (2020): 998-1008. DOI: 10.1515/ntrev-2020-0078. The final publication is available at www.degruyter.com. Attribution 4.0 International (CC BY 4.0). Posted with permission.

Keywords

nano-CaCO3, autoclaved concrete, carbonation, chloride resistance, optimal dosage