Influence du vieillissement sulfatique sur la résistance mécanique et la microstructure du béton

The deterioration of concrete in sewer pipes is the most important problem in assessing the durability of structures. The purpose of this work is to perform an accelerated test, to evaluate the effect of environment sulphatic on the mechanical property and analyze damage to the microstructure of concrete. The evolution of the compressive strength of the specimens aged demonstrates a significant decrease in resistance. This is due to the various and complex phenomena of concrete deterioration. Microscopic observations and X-ray analysis using SEM-EDS were performed on samples of concrete virgin and aged for different aging times. These results were confirmed by EDS spectra, the formation of ettringite which is produced from the chemical reaction between the sulfate (SO42-) and tricalcium aluminate (C3A), developing microcracks on the surface of the pores of the cement paste.