Durability aspects of blended concrete systems subjected to combined mechanical and environmental loading using piezo sensor

In real-life structures, the structural elements are exposed to combined effect of mechanical load and environmental action simultaneously. So, monitoring these structures under combined effect is very crucial to understanding their behaviour under effect. This study compares and monitors the durability aspects of two different concrete systems namely ternary blended concrete and conventional concrete subjected to combined effect of chloride-induced corrosion and compression loading using piezo sensor based electro-mechanical impedance (EMI) technique. Experiments were conducted on two different types of concrete systems, one made with limestone calcined clay cement (LC³) with 50 % by weight as a replacement to ordinary Portland cement (OPC), and the second made with OPC. Chloride penetration, chloride profiles, diffusion coefficient, and surface concentrations were the various parameters considered for the evaluation of durability performance. Further, an equivalent structural parameter (mass, stiffness, and damping) model has been proposed to identify the deterioration in these two concrete systems and an empirical relation has been established between equivalent stiffness and surface concentration for non-destructively monitoring. The results indicate that the percentage loss of equivalent stiffness in OPC concrete system under ideal chloride effect is 27 % more than combined effect, while in LC³ concrete system it is 40 %. On comparing the deterioration of equivalent stiffness in OPC and LC³ systems, it is found that in LC³ concrete system the loss is 20 to 25 % less than that of OPC concrete system. Hence, it is concluded that the deterioration of concrete under the combined effect is significantly less than ideal chloride effect and LC³ concrete system exhibits higher chloride resistance than the OPC concrete system.