Marine aerosol, containing an enormous source of chloride, coupled with severe environmental conditions (e.g., high temperature, high relative humidity), poses a threat to the durability of concrete exposed to the marine atmospheric zone. The distribution of marine aerosol is spatial and temporal dependent, and thus, the deposition rate of airborne chlorides Ddep can vary a lot with geological and environmental factors. Chloride profile in concrete exposed to marine aerosol is a two-zone profile due to the wetting/drying action. The peak chloride concentration Cmax and depth of the convection zone Δx are largely affected by time, materials, environmental conditions which usually is less than 10 mm. Many models based on Fick’s law are developed to predict chloride transport in unsaturated concrete under wetting-drying cycles. However, the prediction of marine aerosol penetration into concrete is far from satisfactory, due to lack of enough experimental and theoretical researches.
2
Dostęp do pełnego tekstu na zewnętrznej witrynie WWW
In cold regions, concrete structures are often subject to the coupled effect of mechanical loading with freeze–thaw (F–T) cycles, which results in a reduced service life. In this paper, the state of the art and challenges regarding the durability of concrete subjected to mechanical loading coupled with F–T cycles are reviewed in depth. The experimental setups used to simulate the coupled effect of mechanical loading with F–T cycles were summarized first, including the shapes of the specimens, operation methods, advantages, and limitations. Subsequently, relevant research methods such as numerical simulation methods and damage characterization methods were presented. Afterward, special attention was dedicated to the mechanism elaboration and performance improvement of the concrete subject to the coupled effect. Finally, some thoughts on potential directions for future work were discussed.
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.