Sodium sulfate attack on Portland cement structures: experimental and analytical approach

Abstract

The industrial development and the advance of the primary sector in Brazil generated an increase in the cases of structures damaged by sulfate attacks. A reduction in material lifetime is one of the most costly factors in the construction field. Therefore, it is necessary to understand the sulfate attack mechanism in order to provide repairs and prevent further attacks. This article aims to understand how the environmental condition and the material properties influence the attack's severity. Hence, it combined an experimental program and analytical model to measure those parameter effects. Experiments show that cement with a higher amount of tricalcium aluminate (C 3 A), as the CP V ARI, presented a more pronounced deterioration. Visual changes such as cracking, crystallization of expansive products and a complete disintegration were also observed. In addition, loss of resistance occurred in the specimens with low slag content. Moreover, the model is useful to predict the delamination depth and to identify the most critical factors influencing the attack through sensitive analysis. Its results were compared with real cases based on literature and verifying the model reliability.

Zero-Cement Concrete Resistance to External Sulfate Attack: A Critical Review and Future Needs

“…To conduct an accelerated test, the use of "natural" concentration values of sulfate ions in the solution appears not acceptable. Therefore, higher sulfate concentrations in solutions would enable the attack to develop faster [50]. Only a few research works in literature illustrate the use of a very high concentration sulfate solution, i.e., 10% Na 2 SO 4 .…”