Quality Assessment of Strengthening of Reinforced Concrete with CFRP by Using Ground-Penetration Radar

Abstract

This article presents a method for assessing the quality of the reinforcement of reinforced concrete structures with carbon fiber sheets using radar wave inspection. This research aimed to discuss the nature of the debonding between the reinforcement material and the structural concrete surface. Simulate the debonding characteristics of the reinforcement work with 3 different sizes of 4 mm thin foam pads to simulate the damage characteristics of different reinforcement systems. with sizes of 100x100,
40x40, and 20x20 mm. It was installed on a column with a cross-section of 200x200 mm., and a height of 1.0 m. The column was reinforced with a surface-mounted carbon fiber sheet, and the test was carried out using the Hilti-PS 1000 X-Scanner radar probe. with a transmission center frequency of 2.0 GHz. Subsequently, the radar signal data was processed from the test results. The dielectric constant is the electromagnetic property of the appropriate object. The study found limitations in the use of radar waves in foam sheet detection due to the small difference in dielectric constant between the medium and the foam sheet. This affects
the consideration of the characteristics of the foam sheet that simulates the debonding of repair work within the scan results. Coupled with the conductivity of the carbon fiber sheet, the radar wave is absorbed and cannot pass through the carbon fiber sheet. As a result, the position and magnitude of the debonding in the carbon fiber reinforcement system with radar waves cannot be assessed as a result.