Influence of carbonation and freeze-thaw on macro-properties of concrete

5th Global Conference on Materials Science and Engineering

Rao, M.J.^1,3 ; Dong, Y.^1,2 ; Yang, H.Q.^1,2 ; Li, M.X.^1,2 ; Yu, Z.^1

Changjiang River Scientific Research Institute, Wuhan, China^1

Collaborative Innovation Center for Geo-hazards and Eco-environment, Three Gorges Area, Hubei Province, China^2

School of Civil Engineering, Wuhan University, Wuhan, China^3

关键词: Alternating cycle;    Dynamic elastic moduli;    Freeze-thaw;    Freeze-thaw cycles;    Premature failures;    Properties of concretes;    Strength of concrete;    Water binder ratio;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/164/1/012005/pdf
DOI  :  10.1088/1757-899X/164/1/012005

来源: IOP

【 摘 要 】

Concrete can be damaged under the effects of carbonation and the freeze-thaw cycle, which is a common cause of premature failure for concrete structures. In this study, range analysis was performed for compressive strength results after carbonation and freeze-thaw cycles for 90 days. A carbonation test, freeze-thaw test, and the alternating cycle of carbonation and freeze-thaws were performed to measure the relative dynamic elastic modulus and flexural strength of concrete samples. The results showed that specimens subjected to thawing first, then carbonation suffered the greatest impairment to strength due to expansion and osmotic pressures caused by water motion after thawing; this caused some of the original closed pores to link together, which loosened the internal organization and increased total porosity. The dynamic elastic modulus loss and weight loss of carbonized specimens were smaller than those of uncarbonized specimens within a reasonable range of carbonation. The flexural strength carbonation declined as the water-binder ratio or fly ash content increased.