|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Characterization of Minerals, Metals, and Materials
||LL-19: Assessment of Concrete Degradation Submitted to the Attack of Magnesium Sulfate through Non-destructive Testing
||Gustavo Lima, Leonardo Pedroti, José Luiz Paes, Roseli Martins
|On-Site Speaker (Planned)
The sulfate ions react with the compounds of the cement matrix and generate expansive product when in contact with concrete. Magnesium sulfate (MgSO4) is one of the most aggressive agents harmful to concrete because it parses CSH silica, alumina and gypsum. This study evaluated the degradation of dynamic modulus of elasticity through natural vibration frequency and propagation speed of the ultrasonic pulse. Specimens were produced with four different ratios water/cement (0.45; 0.60; 0.70; 0.80) and submitted to three different concentrations of MgSO4 (0 g/l, 10 g/l; 50 g/l ) for a period of 90 days. Every 30 days the dynamic elastic modulus was determined and the microstructure of concrete was evaluated by X-ray diffraction and scanning electron microscopy. At all concentrations tested, the results indicate a more severe degradation of the concrete produced with water/cement ratio 0.80.
||Planned: A print-only volume