Exploratory Study on Sulfate Attack Monitoring of Concrete Structures Using Piezoceramic Based Smart Aggregates

Sulfate attack is one of the most frequent environmental attacks affecting concrete structures, which is manifested by expansive disruption and deterioration of cement paste. However, it is difficult to monitor the deterioration induced by sulfate attack as these attacks mainly occur in sulfate-bearing soils or ground waters. In this paper, the tentative experimental investigation on sulfate attack monitoring was carried out by using smart aggregate transducers and an active sensing method is proposed. A number of plain concrete columns with embedded smart aggregates were fabricated and then suffered to salt-fog exposure for several months. Active monitoring methods were performed to detect the deterioration of the specimens using smart aggregates. In addition, testing of the mechanical properties and water absorption ability of concrete specimens at different deterioration times was performed as well. Then the transmission mechanism of stress wave in concrete was discussed. The experimental results show that, with the growth of attacking time, the amplitude of the received signal decreased, and by calculating the damage index, the deterioration degree of concrete specimens was estimated. It is indicated that the proposed piezoceramic based SA monitoring method is valid in sulfate attack monitoring.