Abstract: A penetrating radiation is used to examine a prestressed tendon in a prestressed concrete. A comparing object is used, whose position and size are known in advance. A magnifying rate of an image size of the comparing object projected on an imaging device is calculated. By using the magnifying rate and by comparing the image sizes of the prestressed tendon and the comparing object projected on the imaging device, the defect size of the prestressed tendon can be figured out.

Abstract: Gamma rays, X-rays or ionizing irradiations from two radiation sources penetrate through a steel bar in a reinforced concrete structure. Images of the steel bar are thus projected on two films. Through geometric relationships between the images and the steel bar itself, thicknesses between the steel bar and surfaces of the reinforced concrete structure are obtained. The position of the steel bar obtained according to the present invention is reliable and accurate. And the data obtained can be used for structure safety.

Abstract: The present invention uses a penetrative radiation to form images of a reinforced concrete which has a steel bar. By recording a relationship between radioactive energies and thicknesses of the reinforced concrete, a radioactive energy curve for the reinforced concrete is built. The present invention can be used for an on-site detecting of a reinforced concrete.

Abstract: A penetrating radiation is used to examine a steel bar in a reinforced concrete coordinated with a comparing object. The position and size of the comparing object are known in advance. At first, the steel bar and the comparing object are projected on an imaging device. Then, a magnifying rate of an image size of the comparing object shown on the imaging device is calculated. By using the magnifying rate and by comparing the image sizes of the steel bar and the comparing object on the imaging device, the defect size of the steel bar can be figured out.

Abstract: Gamma rays, X-rays or ionizing irradiations from two radiation sources penetrate through a steel bar in a reinforced concrete structure. Images of the steel bar are thus projected on two films. Through geometric relationships between the images and the steel bar itself, thicknesses between the steel bar and surfaces of the reinforced concrete structure are obtained. The position of the steel bar obtained according to the present invention is reliable and accurate. And the data obtained can be used for structure safety.

Abstract: A gamma ray, an X-ray or an ionizing irradiation penetrates through a steel bar in a reinforced concrete structure. An image of the steel bar is thus projected on a film. Through geometric relationships between the image and the steel bar itself, the size of the steel bar is calculated. The size of the steel bar obtained according to the present invention is reliable and accurate. And the data obtained can be used for structure safety.

Abstract: The present invention measures the strain caused by the shrink and expansion from the corrosion and examines the corrosion of a tendon for a long term with high sensitivity to improve the accuracy of the examination.

Abstract: The present invention uses a penetrative radiation to form images of a reinforced concrete which has a steel bar. By recording a relationship between radioactive energies and thicknesses of the reinforced concrete, a radioactive energy curve for the reinforced concrete is built. The present invention can be used for an on-site detecting of a reinforced concrete.

Abstract: A penetrating radiation is used to examine a steel bar in a reinforced concrete coordinated with a comparing object. The position and size of the comparing object are known in advance. At first, the steel bar and the comparing object are projected on an imaging device. Then, a magnifying rate of an image size of the comparing object shown on the imaging device is calculated. By using the magnifying rate and by comparing the image sizes of the steel bar and the comparing object on the imaging device, the defect size of the steel bar can be figured out.

Abstract: A penetrating radiation is used to examine a prestressed tendon in a prestressed concrete. A comparing object is used, whose position and size are known in advance. A magnifying rate of an image size of the comparing object projected on an imaging device is calculated. By using the magnifying rate and by comparing the image sizes of the prestressed tendon and the comparing object projected on the imaging device, the defect size of the prestressed tendon can be figured out.

Abstract: The present invention examines coherence integrity of a joint interface between a construction and a reinforcing plate steel in a to-be-examined area by comparing a waveform obtained in advance with a back echo waveform received.

Abstract: The present invention measures the strain caused by the shrink and expansion from the corrosion and examines the corrosion of a tendon for a long term with high sensitivity to improve the accuracy of the examination.

Abstract: The present invention is a method for examining corrosion on a reinforcement steel. A sensor with a fiber Bragg grating is connected with a coupler; and the coupler is connected with a laser and an analyzer. Apply the sensor at a proper position on the reinforcement steel. A light source of the laser goes to the sensor through the coupler; and then the light passes the sensor and is transferred back to the analyzer. The analyzer can then figure out the strain out of the deformation and swell on the reinforcement steel owing to its corrosion by detecting the drift of the Bragg wavelength of the light. By doing so, the present invention obtains high sensitivity, strong corrosion sustainability and electromagnetic jam prevention so that the accuracy of the detection becomes higher and it can be widely applied to examine the corrosion on the reinforcement steel in a long term.