Corrosion Resistance of Normal and Silica Fume-Modified Mortars Made from Different Types of Cement
Appears on pages(s):
blast furnace slag; cements; compressive strength; corrosion; modulus of elasticity; mortars (material); silica fume; sulfate resistance; Materials Research
The results of a corrosion investigation of cement mortars immersed in different sulfate solutions of the same concentration are presented. Factors such as the type of cement, aggressive solution, and, in particular, size of specimens are studied. To study the degree of corrosion, several testing methods were used, including expansion, weight channels, compressive strength, dynamic modulus of elasticity, and the amount of bound compounds in the mortars. Previous results regarding the differences in the sulfate resistance of cements with different C 3A contents and the effect of blast furnace slag in blended cement were confirmed on the mortars where no silica fume was added. With silica fume addition, the corrosion resistance of the mortars was influenced markedly, depending both on the type of cement and the particular sulfate anion. The relative aggressiveness of the solutions for both plain and silica fume-modified, from weakest to strongest, was as follows: sodium sulfate < magnesium sulfate << ammonium sulfate. The effectiveness of silica fume in improving the sulfate resistance of cement mortars proved beneficial when combined with ordinary portland cement prior to portland blast furnace slag cement or sulfate-resistant portland cement, mainly in sodium sulfate solution.