Investigation of the effect of corrosion inhibitors in cementitious mortars against aggressive environments

Concrete and reinforced-concrete structures are affected by various environmental conditions. Internal and external factors cause physical and chemical damage to the structure, thereby negatively affecting the durability of the cement matrix. The external and internal aggressive environmental conditions are listed as sulfate effects, F-T cycles, sodium chloride effect, alkali-silica reaction, and reinforcement corrosion. One measure to address these issues is the use of corrosion inhibitors. The effects of mortar structures that contain inhibitors in different aggressive environments are of interest. It has been observed that there is a limited number of studies on the examination of corrosion inhibitors in concrete and mortar structures in the literature. This thesis contributes to the literature by investigating the effects of inhibitors and different aggressive environmental conditions within its scope. Three different corrosion inhibitors, classified as organic, inorganic, and green (environmental), were used in the experiments. The aggressive environmental conditions affecting the samples were determined as the sulfate effect sodium chloride effect, ASR, and F-T cycles. The ultrasonic pulse velocity, unit volume weights, and flexural-compressive strengths of the samples were analyzed. Analyzed, differences were observed according to inhibitor type and ratio. In general, it was observed that the 28 and 180-day strength results were higher with the use 1% inhibitor in mortar samples with standard curing. In D-C cycles, the least strength loss was obtained 5,66% calcium nitrite inhibitor. In the ASR effect, the least elongation of 0,030% was determined 2% calcium nitrite and amino alcohol inhibitors. According to ASTM C1012 standards, the application of 0,005% of the three inhibitors within the 1% concentration exhibited the least length elongation under sulfate effect conditions. Analyzing the strength impact of sulfate exposure on the samples, it's notable that the use of 1% inhibitor enhanced compressive strength compared to the control sample. In the presence of sodium chloride, compressive strength improved with 2% amino alcohol inhibitor. These findings underscore the significance emphasizing the importance of both inhibitor types and concentrations in mitigating aggressive environmental effects.