Enhancing carbonation and chloride resistance of autoclaved concrete by incorporating nano-CaCO 3

Nanotechnology Reviews

article

Guo Li¹  Zheng Zhuang²  Yajun Lv³  Kejin Wang⁴  David Hui⁵ 

[1] Jiangsu Key Laboratory of Environmental Impact and Structural Safety in Engineering, China University of Mining and Technology;School of Mechanics and Civil Engineering, China University of Mining and Technology;School of Civil Engineering, Shenzhen University;Department of Civil, Construction & Environmental Engineering, Iowa State University, United States of America;Department of Mechanical Engineering, The University of New Orleans, United States of America

关键词: nano-CaCO3;    autoclaved concrete;    carbonation;    chloride resistance;    optimal dosage;   

DOI  :  10.1515/ntrev-2020-0078

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Three nano-CaCO 3 (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.

【 授权许可】

CC BY