Deterioration of concrete under coupled aggressive actions associated with load, temperature and chemical attacks: A comprehensive review

Concrete infrastructure subjected to mechanical load or surrounding aggressive environments experiences gradual deterioration of performance. Although many studies have conducted on durability of concrete under single aggressive condition, the related research results have already been well-summarized. The concrete deterioration under coupled actions is severer and more complicated than that under single aggressive conditions. However, few studies have reviewed the studies on this topic. This paper comprehensively reviews the research outcomes of the performance of concrete under various coupled aggressive actions, such as high temperature and impact load, freeze-thaw and fatigue loading, alkali-silica reaction and compression, sulfate attack and dry-wet cycling, chloride penetration and carbonation, as well as acid corrosion and high temperature exposure, and so on. The testing methods, interaction of two aggressive conditions, and strengthening measures have been discussed and summarized correspondingly. The results indicate that the performance degradation under the coupled mechanical load and aggressive environments are much severer compared to the single aggressive environment. The properties of concrete are significantly affected by the severity of coupled aggressive actions, and can be improved at the early-age stage. The experimental methods also have higher impact on the performance of concrete due to different mechanisms, but the difference between under and after high temperature exposures is relatively lower. Finally, some enhancement methods proposed in this review, such as adding fly ash, silica fume, slag, fibers or air-entraining agents, are effective in improving the durability of concrete under coupled aggressive environments.