Damage and Degradation of Concrete under Coupling Action of Freeze‐Thaw Cycle and Sulfate Attack

Abstract

In this study, the mechanical behaviors, failure characteristics, and microstructure of concrete containing fly ash (FA) against combined freeze-thaw cycles and sulfate attack were studied compared with normal concrete, and the formation rates of corrosion products during coupling cycles were investigated. Results showed that, during the coupling action of freeze-thaw cycles and sodium sulfate solution, concrete containing 10% fly ash exposed in 5% sodium sulfate solution exhibited better freeze-thaw resistance. Meanwhile, the variation of compressive strength of concrete during the coupling cycles could be divided into two stages, including the strength enhancement stage and the strength reduction stage. Moreover, the proportion of micropores and capillary pores decreased obviously during combined freeze-thaw cycles and sulfate attack, and excessive concentration of sodium sulfate solution led to more macropores after high-frequency freeze-thaw cycles.

Degradation mechanism and life prediction of tailings and waste rock aggregate geopolymer concrete under freeze-thaw corrosion

“…These co-workers found that incorporation of fly ash and mineral powder can improve the performance of concrete, and coupled with increasing corrosion time, under the action of concrete under uniaxial compressive strength, a trend of a decrease in performance after the first increase was demonstrated. In a study by Tian and Gao [10], under the action of freezing and thawing cycles and sulphate coupling, the mechanical properties and damage mechanism of fly ash concrete were determined, and the results indicate that with increasing cycling times, the rise and fall of concrete compressive strength is divided into two stages: the fly ash content was 10%, the sodium sulphate solution concentration was 5%, and concrete exhibited good frost resistance. Yao et al [11]studied the degradation mechanism of concrete in a maintenance freeze-thaw (MFT) environment and a soaking immersion freeze-thaw (IFT) environment and measured the change in the pore structure and microstructure of concrete by using scanning electron microscopy (SEM) and mercury injection porosimetry (MIP).…”

Study on the Performance Evolution of Hydraulic Concrete under the Alternating Action of Freeze–Thaw and Abrasion

“…Currently, the majority of the existing research is devoted to the influence of a single factor on the performance of hydraulic concrete, while research under the action of multiple factors is relatively scarce [12]. For example, the addition of an appropriate amount of fibre into pervious concrete can enhance its resistance to wear while enhancing permeability by modifying the structural framework of concrete, thereby reducing the erosion damage inflicted by high-speed water flow [13][14][15].…”

Modelling of Damage Spatiotemporal Distribution in Saturated Cementitious Materials and its Chloride Transport Evolution

“…Cracks in concrete are usually caused by restrained volume changes, e.g., shrinkage, temperature effects, and durability problems (Tian et al 2020;Corr et al 2001;Chernin, et al 2011). During the hydration process, concrete will shrink, and tensile stress will develop if the shrinkage is restrained.…”

“…Thermally-induced cracks are prone to occur in mass concrete. Moreover, durability problems can also lead to cracks, such as freeze-thaw action, alkali-aggregate reaction, sulfate ingress, and steelbar corrosion (Tian et al 2020;Corr et al 2001;Li et al 2021). Other reasons for concrete cracking could lie in poor construction practices, construction overloads, errors in design, and externally applied loads.…”