Tiếng Việt
Experts said that Thang Long bridge was repaired in the direction of increasing the stiffness of the deck, solving the problem of adhesion between the deck and the upper coating.
At the seminar on repairing the Thang Long bridge surface held by the Ministry of Transport on the morning of July 30, Prof. Dr. Tran Duc Nhiem, the University of Transport, said that previously this bridge was damaged by secret large vehicle size (about 47,000 vehicles per day), thin steel plate structure, bridge deck is dragged in both vertical and horizontal direction, and is sagged locally.
In the recent repairs, the coating of the concrete bridge surface does not meet the load-bearing requirements, the adhesion between the bridge deck coating and the steel deck is poor, so the life is not long.
According to Mr. Nhiem, this repair the steel plate deck will be renovated into a light composite deck; steel faceplate bonded with super-functional concrete with anchor nails; then carpet a layer of asphalt concrete on top of the layer to create roughness and adhesion.
“This repair will increase the hardness of the bridge deck, solve the problem of adhesion between the deck and the coating in the case of heavy trucks, waterproofing the bridge surface,” said Mr. Nhiem.
Prof. Dr. Tong Tran Tung, former lecturer of the University of Transport, evaluated the results of Thang Long’s stable structure, only damaged the coating above. In 2009, repaired by an unsuitable waterproof and non-adhesive concrete connection in Vietnam. When driving and this class is not fully loaded, so it is quickly pushed and degraded. The quality repairs after implementation are patched up to ensure favorable conditions.
“The goal of this repair is to create a connection between the large coatings with the steel surface, strengthen the rigidity of the frame and the bearing structure to prolong the bridge’s service life,” Tung said.
Mr. Nguyen Trung Sy, Director of Construction Management Department (Directorate for Roads of Vietnam), said that the new welding technology to the plate (to connect the surface to the above concrete layer) will not change. Bearing structure of the perennial record of the request.
“This technology has been applied in many countries such as the Netherlands, Belgium, Germany, France, the US, China. We believe that the repair of Thang Long will be successful with over 10 years”, Mr. Sy did not sedge.
The project of repairing the Thang Long bridge surface is invested by the General Department of Roads of Vietnam with an investment of VND 269 billion. Expected on 9/8 next will restart and complete repairs by the end of this year.
Thang Long Bridge crosses the Red River, the company records the Vietnam-Soviet friendship relationship, connecting the Northern provinces with Hanoi capital. The bridge was designed by Russian experts and built in 1974, completed in 1985. More than 20 years of use, required many times to degrade and be repaired many times with a cost of hundreds of billion VND.
During the repair and arrangement process, the request for Thang Long will be directly reinforced with the current direction into a lightweight bonding surface; raking off the owner concrete layer, cleaning the surface, welding the nail into steel and installing steel D10. The deck is reinforced with super-functional concrete with compressive strength, 6 cm thick and a concrete carpet of 4 cm long; replace damaged expansion joints with modular expansion joints.
