Today, one of the most important components of sustainable urban development is the improvement and expansion of communication networks, including highways, urban arteries, and bridges. Among these, urban vehicular bridges are the most important factor connecting communication networks and must be given special attention during construction and maintenance. Unfortunately, in our country, this issue has often been overlooked.
One of the aspects requiring special attention in the construction of urban vehicular bridges is the proper design and execution of expansion joint systems in bridges. If sufficient attention is not given to the construction, installation, and maintenance of these systems, it can result in severe and sometimes irreversible damage to the bridge structure, disrupt traffic flow, and even endanger safety.
According to technical surveys of bridges in Tehran, the most common existing expansion joint systems are based on the movement of steel plates covering a metal frame (angle iron) and using simple rubber expansion joint systems or a combination of both. These methods have numerous disadvantages and do not provide the required efficiency. Some of these drawbacks include insufficient strength to withstand the loads caused by vehicle traffic, the rising of plates due to vibrations of the deck, longitudinal distortion of the plates, detachment of the angle iron from the concrete deck, rigidity of the simple plate and angle iron systems, lack of protective heels, and, most importantly, the inability to create a water-tight seal, allowing water to enter and turn the expansion joint area into cement during operation.
Using innovative methods to rebuild expansion joint systems in concrete bridges, in order to improve their quality and utilize domestic capabilities, based on practical experiences and observations, is one of the actions that Tehran’s municipality has put on the agenda.
This article presents a different method for rebuilding expansion joints up to 10 centimeters (small S-EXJ expansion joints) for vehicular and pedestrian paths in reinforced concrete deck bridges, based on domestic rubber expansion joints. In the execution method of Type 7 (TYPE-EXJ), the selection of the expansion joint type is based on rebuilding operations in reinforced concrete deck bridges, using domestic rubber expansion joints of Type 80T and cement-based mortar for the vehicular path.
Execution stages of the 7TYPE-E method
In this proposed method for implementing the expansion joint system, to ensure the smooth flow of traffic, after constructing and installing the metal frame, asphalt paving is applied on the roadway surface. The execution steps are as follows:
مرحله اول:
Step 7:
