Inspection of bridge structures
Inspection of bridge structures is aimed to determine its technical state, defects and damages, preparing recommendations for the elimination and prevention of defects and damages, for further exploitation, repair, reconstruction of buildings as well as for the purposes of the movement, and for other purposes.
The main task of the inspection of bridges before putting them into operation is to establish the conformity them with the construction standards, approved project and quality of works.
Inspection of bridge structures are conducted:
- at commissioning after construction or reconstruction;
- after completing repair and overhaul;
- periodically during the operation to monitor the state of structures and planning of their repair;
- for project design, renovation, major repairs or reconstruction.
The inspection involves the following steps:
1. Preparatory phase - definition for inspection of structural elements of the bridge for future inspection, providing access to scheduled for inspection structures, assessing the completeness of the available technical documentation, assign the necessary tool of research, preparation and coordination of the Inspection program.
2. Acquaintance with the technical documentation includes the study of executive documentation to verify conformity with the designed works. During this phase the project and their harmonization with the design organization (if they occur) are identified, the history of records of the author's supervision and the log of the executed works are examined. The accuracy of performed work acts (acts of hidden works, certificates and installation connections the installation of supporting acts, parts, expansion joints etc.) are checked. Attention is given to the control input log entries - certificates, passports for applied design, and other documents.
3. Inspection of bridge structures includes a visual inspection and instrumental studies that identify defects and deficiencies. When inspecting metal structures, quality of welded and bolted mounting connections (the existence of surface defects in welds, correctness of bolts installation), the quality of protective coatings application, the availability of General and local inelastic deformation elementsvisually controlled. Visual inspection of concrete structures aimed to detect cracks, leaks, blooms, defects and damage of the protective layer of concrete.
4. Instrumental studies are conducted to assess the conformity of the actual geometric dimensions, as well as the physical and mechanical characteristics of applied materials to the design ones. To assess transport and operation characteristics of the roadway of the bridge, according to ONE 218.017-2003 the surface of the concrete is inspected.
Specialists of IMIDIS institute hold following instrumental examinations:
- Measurement of the protective layer of concrete:
with "Proceq profometer 5" device (Switzerland)
with "POISK 2.3" device
with IZS-10C device
- Definition of concrete strength by non-destructive testing according to GOST 22690-88:
using Digi Shmidt 2000 (Switzerland) by the method of elastic rebound
with the "POS-50MG" device and using break away with shear fracture method:
using ultrasonic instrument Proceq Tico (Switzerland)
- Assessment of reinforcement corrosion by electric potential measurement.
- Define the depth of carbonization of concrete.
- Determination of moisture content in concrete by GANN Hydromette UNI-2
- Measurement of water resistance of concrete on its degree of air permeability using "Agama" device
- Determination of paint coatings thickness by method of non-destructive testing according to GOST 51694-2000 using a thickness gauge of electromagnetic type Mt-201
- Determination of the depth of cracks with "Beton-32" device
- Determination of the adhesion of coatings and materials enhance to the elements of constructions
with "PosiTest AT" device
with "Adgezimetr РН" device according to GOST 15140-78 and ISO 2409:
- Measurement of stresses in a tense fixture with "EIN-MG-4" device and using the method of free vibrations frequency measurement
- Measurement of stresses in the reinforcement wires using retraction method and "DP-6" device
- Geodetic measurements with GPS/GLONASS-complex "Ashtech" (preparation of the longitudinal and transversal profiles of carriageway, measuring on the lower surface of the spans, verification of the conformity of the actual project marks)
- Measurement of structural elements temperature with «TESTO 875» thermal imaging camera