Deterioration of High Performance Hybrid Fibers Reinforced Expansive Concrete Exposed to Magnesium Sulfate Solution

Deterioration of fly ash concrete, high performance concrete, and high performance hybrid fibers reinforced expansive concrete(HPHFREC) exposed to 5% magnesium sulfate solution is investigated. Two corrosion regimes were employed: natural immersion and dry-wet cycle. From the experimental results, it is found that erosion of concretes under combined action of magnesium sulfate and dry-wet cycles is more severe than that in single magnesium sulfate corrosion, and the dry-wet cycle accelerates the deterioration of concretes in magnesium sulfate environment. In early exposure period, concrete has a structure reinforced phase during which dynamic modulus of elasticity and mass of concretes increase steadily. Among the four types of concretes tested, HPHFREC gets the best corrosion resistance and surface peeling resistance in magnesium sulfate environment.