Corrosion Induced Damage Monitoring of Engineered Cementitious Composite Containing Ceramic Wastes by Acoustic Emission

Fiber-reinforced cement-based materials have received extensive attention in the field of structural strengthening. Using ground ceramic powder to replace part of cement, and using crushed ceramics to completely replace quartz sand, an environmentally friendly cement-based material was prepared. A new type of engineered cementitious composite (Cera-ECC) was obtained by adding an appropriate amount of polyvinyl alcohol (PVA) fiber. Electric accelerated corrosion was introduced to study the corrosion of steel bars in Cera-ECC and the damage process of the surrounding engineered cementitious composite (ECC) using acoustic emission technology. It is found that the introduction of ceramic powder in an appropriate amount can form a stable passive film on the surface of the steel bar. The cumulative acoustic emission hits over time shows that the damage process can be divided into five stages—before depassivation, rupture of the passive film, accumulation of corrosion products, internal expansion and cracking, and formation of macroscopic cracks. Signals at different stages of damage have different spectral characteristics. As the damage continues to increase, the peak frequency of the acoustic emission signal gradually changes from low to high. With the increase of fiber content, the appearance time of macro cracks is effectively prolonged.