INVESTIGATING DAMAGE IN REINFORCED CONCRETE MEMBERS USING A VIBRATING WIRE STRAIN GAUGE

Abstract

Recently the use of vibrating wire strain gauges has increased to find out the damage in a reinforced concrete structure. The assembly and functioning of this acoustic strain gauge are presented. This gauge provides numerous benefits including its sensitivity to measure strain (up to 1micron) and its property of being easily attached on any concrete surface. The gauge apparatus can be made in a lab due to its low cost which gives it an edge over the conventional systems. The gauge was calibrated after considering the variations in temperature. The purpose of the experimentation was to record the changes in nonlinear vibrations with respect to the damage caused in the reinforced concrete member. These changes were later studied using the vibration tests on the reinforced concrete beam. Non- linearities were observed by the changes in the fundamental frequency. Discrete Fourier transforms moving window was utilized to analyze the vibration signals specifically the change in frequency with respect to time. The results are presented and reviewed.