254 / 2022-07-30 07:51:29

A prediction model of the failure thickness of concrete under sulfate attack

Concrete, Durability indicators, Prediction model, Sulfate attack

The durability of concrete under the sulfate attack environment is hard to predict as the deterioration performance is not described quantitatively. The indicators, such as strength, elastic modulus, mass, and length variations, do not provide sufficient information to assess the damage mechanisms, and they are difficult to obtain accurately in the actual engineering environment. In this research, a durability failure index, failure thickness of concrete materials under sulfate attack was defined. Experiments of sulfate attack were carried out and the correlation analysis of the failure thickness and the change rate of the dynamic elastic modulus and compressive strength of concrete was analyzed. It’s found that the failure thickness can reflect the changing trend of the mechanical properties of concrete under sulfate attack. Furthermore, a prediction model for the failure thickness was established in relation to attack time, sulfate solution concentration, concrete initial aluminate content, and diffusion coefficient. The results show that the failure thickness increases with the increase of the sulfate solution concentration and the diffusion coefficient, and the changing trend of the influence on the failure thickness presents a logarithmic curve. Whereas, the increase of aluminate concentration decreased the failure thickness to a certain extent, showing a negative linear correlation. The established model was verified by experiments, the results show that the predicted thickness was close to the test results, and the model is reliable. These studies help to further develop the durability design and life prediction of concrete structures under sulfate attack environments.