ONE-YEAR SULFATE ATTACK: INFLUENCE OF CERTAIN FACTORS ON THE CONCRETE PROPERTIES

Abstract

A large amount of aggressive ions, especially sulfate ions, is present in the soil and groundwater as well as in marine environment, which could lead to the deterioration of underground and offshore concrete structures in those areas. In the last few decades, the problem of the sulfate attack on building materials and structures has attracted considerable attention and is considered very important issue. Regardless of the increased interest and research, there is always a need for further research both because of the complexity of the sulfate attack and the long-term effect itself. The aim of the research presented in this paper is to try to determine the impact of the selected factors and their combination on certain properties of concrete using a mathematical-statistical analysis "Factorial Experiment", which evaluates its sulfate resistance after one year of exposure to 5% sulfate solutions (Na2SO 4 and MgSO 4). The considered parameters included in this are the type of cement (CEM I and CEM III), the water-cement ratio (0.55 and 0.38) and the type of aggregate (river and aggregate from recycled concrete), while the selected properties through which sulfate attack is monitored are capillary absorption, length change and change in compressive strength. Based on the results of the analysis, it is difficult to draw a clear conclusion about the influence level of the key factors of selected properties for evaluation the sulfate resistance of concrete mixtures for the observed sulfate exposure period of one year, but it provides a contribution to further studies in this topic.