Application of Near-infrared Spectroscopy for Inspection Concrete
By H. Kanada, Y. Ishikawa and T. Uomoto
Concrete Journal, Vol.43, No.3, Mar. 2005
- Synopsis
- Many non-destructive inspection methods have recently been developed for concrete structures. However, these methods can obtain only physical information of concrete, such as crack depth, delamination or position of reinforcement etc. near its surface. A remote non-destructive method that can detect deterioration factors such as carbonation, chloride content or sulfate attack would be an outstanding innovation in inspection methodologies. In this research, remote non-destructive material detection of concrete was attempted using NIR spectroscopy. This enables us to obtain chemical information of concrete by just sensing reflected near-infrared rays from the measuring plane. Dispersed near-infrared rays through the spectroscope can be received in each wavelength by light-sensitive elements on NIR CCD camera. Finally, distribution or concentration of the target component can be observed as an image. This paper describes the detection method of carbonation, chloride and sulfate attack as examples. Applicability of this method for inspection has been corroborated by exaperimental results.
- Keywords:
- spectroscopic technique, near-infrared spectroscopy, optical properties, near-infrared spectral imaging
