Thermodynamic Study of Cement Paste under Sulfate Attack: A Review

Abstract

Sulfate attack reduces the service life of concrete structures, which isn't possible to repair simply. Implementation of many factors influencing the sulfate resistance, sample scaling, and results in the least possible time is some problems of experimental studies. Therefore, numerical simulations, as well as the new methods along with experimental studies, have been led to better evaluation of sulfate attack within a shorter time and at a lower cost. In the present study, the effective factors, causes, and mechanisms of sulfate attack, examples of this phenomenon in real projects, and the previous studies in this regard, in particular, the development of the thermodynamic study of cement under sulfate attack as a fast and inexpensive solution have been reviewed. The present investigation is divided into three parts, first the sulfate attack mechanism, second the factors influencing phases containing sulfate formation, and third a review of the methods and results of the studies, focusing on the development of thermodynamic models in cement sulfate attack especially. Finally, the results of the studies show that common experimental methods related to concrete sulfate resistance evaluation can't always simulate what is actually happening; subsequently, the results of experimental studies and real cases are sometimes different. So, numerical models, in particular, thermodynamic simulation, either alone or in combination with experimental studies, can be a desirable solution for enhancing the ability to predict engineering behavior of concrete structures in the sulfate environment. Subsequently, it results in making better decisions to tackle and prevent deterioration caused by sulfate attack.