The progress of repairing the Thang Long bridge deck is slow and the reason given is waiting for Chinese experts. Therefore, many opinions believe that the technology to repair Thang Long bridge comes from China. Where does this technological solution to repair the bridge deck actually come from?
The Thang Long Bridge repair project was officially started and construction began on August 16. It is expected that the project will be completed by the end of the fourth quarter of 2020.
The process of repairing the Thang Long bridge deck includes the following main steps: scraping off the existing asphalt concrete layer, cleaning the steel surface and anti-rust painting; weld steel anchor studs to the steel face plate; steel mesh installation; pouring ultra-performance concrete (UHPC) with compressive strength of 120MPa, minimum thickness of 6cm; Create roughness and apply an adhesive layer then cover the bridge surface with 4cm thick polymer asphalt concrete.
With these solutions, the leaders of Vietnam Road Administration assessed that after being repaired, according to the results of calculations and experiments on the model, the hardness of the bridge deck increased at least 3 times.
In addition, the project also repaired other items to synchronize with the road surface such as replacing 6 damaged expansion joints; Repairing pedestrian sidewalks, drainage systems and traffic safety systems.
Due to the complex nature of the project, the Ministry of Transport established a steering committee for the Thang Long bridge deck repair project, and the Vietnam Road Administration also established a team of technical experts with extensive experience in the project. This technology.
“The Thang Long bridge deck repair solution uses core European technology, with a team of domestic experts and engineers mastering the main contents of design and construction work. The entire process of researching and proposing repair solutions and carrying out construction is carried out by domestic consultants and construction contractors with technical support from leading experts in the fields of structure, domestic materials, not receiving technology transfer from any country," the leader of the Directorate for Roads affirmed.
Recognizing that technological solutions for repairing Thang Long bridge are applied in many European countries, the Directorate for Roads believes that the entire expansion joint system is imported from Mageba (Switzerland). ). Meanwhile, project construction materials are mainly domestic materials, paving machines, concrete compactors, contractors may have to import from Korea, Japan, China, Europe... or can do it themselves. make. The work of scraping and cleaning the old bridge deck coating, construction of the adhesion layer and Polymer asphalt concrete mats was carried out by engineers, technical staff and workers of Phuong Thanh Company.
In particular, the equipment used to construct the project includes a mixing plant to produce UHPC mixture imported from Denmark by Skako; UHPC spreading and steam curing equipment are imported from China. All equipment operations from UHPC material production, mixing, spreading and maintenance are performed by engineers, technical staff and workers of Thanh Hung Company.
Regarding the Chinese experts in the project, the leader of the Directorate for Roads said that these are two technicians carrying out the handover and operating instructions of equipment under the contract for procurement of spreading and maintenance equipment. Contractor's UHPC.
“Currently, the preparations for UHPC concrete construction are still being implemented on schedule and the entry of technicians does not affect the progress of the project. The selection of equipment is made by the contractor on a technical and economic basis and will be strictly checked according to the technical standards of the project," the leader of the Directorate for Roads emphasized.
WHY NOT CHOOSE RUSSIAN TECHNOLOGY?
In response to questions from public opinion over the past few days about why technology from the former Soviet Union and now the Russian Federation was not chosen to repair the Thang Long bridge deck, Mr. To Nam Toan, Director of the Department of Science and Technology (General Department of Science and Technology). Vietnam Road Administration) said that the Russian expert's request was not in accordance with Vietnamese law, so it could not be chosen.
Specifically, with the desire to repair the Thang Long bridge deck using original technology, the Directorate for Roads searched documents and records and found Dr. Sakharova, who participated in the design and construction of the Thang Long bridge deck. On August 1, 2018, the General Department sent a letter requesting Ms. Sakharova's cooperation to repair the Thang Long bridge deck.
On August 2, 2018, Ms. Sakharova replied in a letter confirming that she could cooperate and requested to transfer documents for study first and at the same time the Russian side would survey the actual situation. The Directorate for Roads has transferred documents about Thang Long Bridge to Ms. Sakharova.
From September 17-23, 2018, the Russian expert was Dr. Kazarin Vilgen Yurevich, General Director of SK MOST Company, who was sent by Ms. Sakharova to work with the Ministry of Transport and inspect Thang Long Bridge. . SK MOST Company proposed that the estimated consulting cost be 7-8% of the bridge deck repair cost, equivalent to about 14 billion VND.
“This proposal is against Vietnamese law so it cannot be implemented as requested. Signing a contract without approval from all levels is not in accordance with Vietnamese regulations," Mr. Toan said.
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| The Thang Long bridge deck was thoroughly repaired and ensured a long lifespan. (Photo: Viet Hung/Vietnam+) |
Not only that, through official diplomatic channels, on March 23, 2019, the Ministry of Transport sent a document to the Ministry of Industry and Trade to propose in the meeting of the high-level working group on priority investment projects in Vietnam. -Russia lets the Russian side support and share experiences in repairing Thang Long bridge and technology for maintaining bridges and roads in general.
On July 4, 2019, a letter sent by Deputy Minister of Economic Development of the Russian Federation AM Talibov to the Ministry of Industry and Trade of Vietnam stated: "The Ministry of Economic Development of the Russian Federation has sent a request to SK MOST Company , along with the Vietnamese side's request, to participate in repairing Thang Long bridge, but the company did not show interest."
Due to not receiving a reply from the experts and SK MOST Company, based on your reply and the need to repair the Thang Long bridge deck, on September 25, 2019, the General Department of Roads reported The Ministry of Transport allows preparation of investment in the Thang Long bridge deck repair project./.
Source: Construction Newspaper
