Repair and maintenance of bridge expansion joint
1, the development of detailed construction protection scheme
Bridge expansion joints maintenance is generally in the traffic section of the implementation, the construction site of the safety work is very important, especially in the relatively large sections of the road construction is more detailed construction plan to be developed.
2, to clean up the damaged part of the concrete
To clear the damaged part of the concrete, to remove to the top of the beam plate, damaged parts and parts of the integrity of the joints to be cut neatly, easy to repair parts and the original parts can be very good combination for a whole.
3, re assembling welding steel
The damage of reinforced welding lashing should pay attention to cold, not hot bending, reinforced hole diameter larger than diameter of steel, in the process of steel bar connection must be closed on with steel, reinforced direction should be symmetrical, do not allow a fracture phenomenon.
4, template thickness selection
The thickness of the template than the slot width 5 cm thick, ca. 20 cm, the height ratio of the notch depth of 4 cm below the foam board, support to the firm, the best use of wire rope lashing, no slurry leakage blockage phenomenon.
5, the health of concrete
The last step is concrete health, health do not equal to naught. Health should be used when plastic film curing, health should be closed tight, no air to enter, during the opening section of health must strengthen inspection efforts, make sure that no vehicle in the above passage. A time to reach more than 7d, the standard to measure intensity open to traffic.
Common diseases of bridge expansion joints
The current rapid economic growth, the bridge construction has also made gratifying achievements. The bridge expansion joint is an essential part of each bridge in the facility, can be said that the damage of bridge expansion joint directly affects the safety and use of the bridge. Therefore we in view of the bridge expansion joint disease following analysis:
1, expansion joints: this disease is due to difference in abutment, installation error and bearing pad stone fragmentation causes of bridge pavement side by side is lower than that of expansion joints due to impact load caused by the bumping phenomenon of the damage.
2, expansion joints rubber damage: this disease is mainly caused by the installation of the bridge expansion joints of the rivet loose, rubber plate deformation, fracture and so on.
3, the expansion joint plug: the reason for this disease is unknown in the sand, garbage and other debris accumulation caused by the free expansion joint position sizing performance of bridge expansion joints, when the ambient temperature rises of the bridge location, bridge girder can produce certain displacement expansion, if thrust between the beam and the beam seriously. There is also likely to lead to a girder jacking or abutment wall cracking phenomenon.
4, the expansion joint is too narrow: not easy to cause the disease in the form of appropriate design and installation of bridge expansion joint width in Luqiao construction, expansion joint is too narrow to reduce the reservation amount of compression, the bridge joints appear crushed to death case caused by bridge pits and other phenomena.
5, steel joints: deformation of bridge expansion joint rubber sealing strip damaged, broken concrete anchorage zone, joints weld fracture, may cause deformation of shaped steel expansion joints.