Using electric response to mechanical impact for evaluating the durability of the GFRP-concrete bond during the freeze-thaw process

The paper proposes a contactless method for assessing the durability of the bond between glass fibre-reinforced polymer (GFRP) rebar and concrete under cyclic freeze-thaw conditions. The method is based on measuring the electric response to mechanical impact. Time- and frequency-related features of the measured signals are examined in a series of experiments with an increasing number of freeze-thaw cycles. The results of the theoretical and experimental studies of the electric response parameters under changing conditions of the rebar-concrete interface are presented. The experimental results demonstrate that the proposed method can be used to monitor the behavior of the rebar-concrete bond. The comparison of the proposed method with the acoustic method shows the former's higher sensitivity.