Comb-type expansion joint characteristics:
1. Large expansion and contraction, shallow burial
Steel plate comb-shaped expansion joint device, designed with a permissible expansion capacity of 40 1000mm, suitable for all kinds of non-existing beam structures, new bridges and old bridge reconstruction of different spans, with large expansion and contraction capacity and wide range of use.
Steel plate comb-shaped expansion joint device, the overall structure height 30 40mm. There is no need to change the structure of the original beam end, and the effective anchorage strength can be achieved by shallow burial. Under normal circumstances, after the expansion and contraction amount is 80mm, the overall height of other types of expansion devices is high, and the overall height of special-shaped steel expansion devices is 250mm. During the design, special treatment must be carried out to the beam end structure, and the construction difficulty is increased simultaneously, therefore, the expansion and contraction amount is large, and the shallow burial fully shows the unique technical advantages of the expansion device.
2. There is automatic slag removal in the comb-type telescopic gap
There is a common problem with the different types of telescopic devices. There are ash and hard objects blocking the expansion gap, which affects the normal expansion and contraction of the beam in serious cases. Steel plate comb type expansion joint device, due to the special treatment of the structure, the comb tooth expansion gap is located on the end face of the unilateral beam, and the bottom surface of the comb type has a stainless steel slide plate cushion at the same time, and the ash and hard objects can only stay on the surface, so that the ash and hard objects can be automatically discharged from the expansion gap with the help of the expansion process of the comb steel plate and the effect of vehicle driving, so that it will not cause blockage, do not need to be manually cleaned, and do not affect the normal expansion and contraction of the beam body.
3. It has excellent waterproof and dustproof performance.
The steel plate comb-shaped expansion joint device is provided with two layers of neoprene waterproof layer, and waterproof ointment is poured in the expansion gap of the comb-shaped steel plate to achieve excellent waterproof and dustproof effect, effectively protect the structure under the bridge and delay the corrosion of the bearing, and prolong the service life of the bridge.
4. The overall performance of the telescopic device and the road surface is good
The steel plate comb-type expansion joint device adopts measures such as rigid-flexible combination, which completely eliminates the condition of jumping when the car is driving from the structure, and the two sides of the expansion device are protected by high-grade ribbon-like rigid concrete, and the overall rigidity is good. Therefore, the vehicle runs smoothly, without impact vibration, reduces the impact force of the bridge, reduces noise, and prolongs the service life of the bridge and the vehicle.
Comb bridge expansion joints can be used on both new and old bridges, and their advantages are:
1. The surface layer plate is a comb-tooth anti-skid channel steel plate, and the supporting structure of the two sides of the panel gap is meshed with each other, and the expansion and contraction amount can reach 420mm, + a large degree of displacement can be accepted.
2. The construction height is low, there is no need to reserve the installation groove, and the comb-tooth bridge expansion joint can be installed within the height of the bridge deck pavement layer, which greatly facilitates the design and construction.
3. It has a wide range of applications, and can be used on both new and old bridges, especially for the replacement of expansion joints of large-displacement rubber plate bridges of old bridges, which is irreplaceable for expansion joints of modular large-displacement bridges.
4. It has component transportation, convenient installation, does not need to be transported by ultra-long car, and does not use crane for loading and unloading. This product has a low cost of construction. The price can save about 20% compared with the modulus large-displacement telescopic installation.
The steel plate of the expansion joint of the comb bridge has been exposed for a long time, which is directly load-bearing, which also exposes some problems
Comb plate disease. The comb plate is deformed or warped, uneven, the transverse gap of the tooth plate is uneven, the teeth are jammed, the tooth plate is broken, and the whole piece falls off.
Rotation control seat, rotating shaft disease. The comb teeth rotate inflexibly, causing the tooth plate to be warped, which affects driving safety.
Judging from the situation of some steel expansion devices that have been damaged, the causes of damage include design problems, processing technology problems, construction quality problems and management and maintenance problems. This type of telescopic device is prone to deformation during processing and use. It is difficult to ensure that the tooth plate and the backing plate are fitted, but the gap is generated, the force on the connection part is very unfavorable, the surface causes noise jumping, coupled with the day and night operation, the tooth plate causes premature fatigue under the action of repeated loads, the fastening bolt (or screw) is loose, and the comb plate rotates and is exposed. Debris is easy to jam the comb tooth gap, affecting the telescopic function, imperfect drainage function, debris and sewage fall under the bridge, polluting the environment, and producing corrosion. It is one of the important issues in the future.