(1) Ultrasonic testing
Ultrasonic method for non-damage detection, is to use ultrasonic as a medium, to obtain the internal information of the object of a method, ultrasonic method has been used in medical diagnosis, steel flaw detection, fish detection and many other fields. Crack depth determination is basically done by placing the transmitting probe and receiving probe near cracks on the same surface of concrete, but there are many specific methods due to the different types of waveforms selected (longitudinal, shear and surface waves) and acoustic parameters (speed of sound, frequency, phase, etc.).
(2) Impact elastic wave method
Generally, the waves propagating in the elastomer body are collectively referred to as elastic waves, and the elastic wave detection method is generalized by artificially emitting elastic waves into the elastomer body to detect the state in the elastomer. The principle of the shock elastic wave method is the same as that of the ultrasonic method, but it is much deeper than the crack depth measured by ultrasound, and the shock elastic wave method can only detect simple cracks where the expansion direction is at right angles to the surface, and there are no branches.
(3) Acoustic emission detection method
Acoustic emission detection method is also the use of elastic wave for acoustic detection of specific detection methods to detect cracks, and the biggest difference from other methods is that only the cracks that are occurring, can not detect the old cracks that have occurred, the cracks that are occurring can detect the location of the cracks (acoustic emission source positioning), the size, propagation and type of cracks, and the depth of the cracks.
(4) Photographic testing method
Photographic detection method is mainly used to investigate cracks on concrete surfaces, including ordinary cameras, video cameras, radiation, infrared photography, etc. for detection.
(5) Monitoring by sensing instruments
The use of instruments buried in concrete for crack monitoring, conventional technology is the use of Carlson or string type seam detector, its control range is only 0.12 ~ 1, is a point detection, due to the spatial randomness of cracks, so often missed detection, in order to timely and omission to monitor cracks, must implement a wide range, continuous, distributed monitoring, the so-called full distribution monitoring.
(6) Optical fiber sensor network monitoring
Optical fiber sensing application in structural engineering monitoring began in the early 90s of the 20th century, such as aerospace vehicles, bridges, etc. temperature, vibration, strain detection and other cracks can be monitored with the light intensity change of the optical fiber embedded in the concrete, and the positioning of the crack can be completed by the sudden drop in light intensity of the multimode fiber at the crack or diagnosis, through the crack loss mutation point on the attenuation curve, the location of the crack can be accurately determined, for the characteristics of concrete crack detection, the optical fiber crack sensing network based on optical time domain reflection technology was developed. It can realize the distribution detection of bridge concrete structure, where cracks intersect with optical fiber sensor network, can be perceived, and can be widened, positioned, and oriented.
The bridge testing institute of Zhongjiao Road and Bridge Technology Co., Ltd. is an institution engaged in bridge inspection. Our institute has photoelectric deflection meter, digital crack width gauge, ultrasonic crack sounder, DASP2003 vibration signal acquisition analyzer, HY-65B3000B digital surface strain sensor and other testing equipment, and equipped with technicians with many years of testing experience to ensure the authenticity and accuracy of bridge testing results. Undertake bridge appearance survey, bridge dynamic and static load test detection, bridge construction monitoring, bridge CT, temporary support of large transportation bridges and aperture friction coefficient detection.
Some bridge inspection cases
1. Static load test test of 26 bridges of Inner Mongolia High-grade Highway Construction and Development Co., Ltd.;
2. Static load test test of No. 1, 2, 3 and No. 4 temporary bridges of Xinjiang Muzati River three-level hydropower station;
3. Zhangjiakou bridge static load test detection;
4. Beijing Fangshan Qiyi Bridge static load test test;
5. Inner Mongolia National Highway 110 overpass completion acceptance test test;
6. Static load test test of the first and second bridges of the Yellow River in Baomao, Inner Mongolia.
7. Pingshan Yehe Bridge static load test test.
Some of the text source network, invasion and deletion.