The journey to be born with Vietnamese hot plastic concrete mixing station

In 1987, on a business trip at Cai Lan port, Quang Ninh to study mechanical engineering, engineer Nguyen Binh stumbled upon a hot plastic concrete mixing system with D508 symbol, supported by the Soviet Union. The machine was covered with dust, rust and quietly lying in a nearby forest, most of the lost parts. With the experience of repairing concrete mixing stations in many localities, he and his teacher, Assoc. Hot in the future.

Assoc.Prof.Dr. Nguyen Binh said that in order to buy a mixing station, Mr. Hop had to borrow a large amount of money from colleagues with an interest rate of 9%/month. This loan is partly used to pay the Ministry of Agriculture – the unit that owns a mixing station system, partly to transport the machine from Quang Ninh to Hanoi.

The recovery work begins at the University of Transport University. More than six months of work, the team recovered 50% of the mixing station but no unit asked to buy. The principal debt has not been paid, the interest is increasingly piled up, causing two teachers and students to fall into a state of extreme tension. “At that time, if I could not sell the concrete mixing station, could not pay the debt, it was only a way to go to prison,” said Associate Professor Binh.

In the deadlock, Nam Dinh Urban Construction Company contacted to buy the machine. The deposit from the contract helps the research team pay a part of the debt and continue the work. However, the recovery process is not simple. The semi -automatic control system – the most important part cannot be repaired or bought new, forcing the group to research. This task was assigned to engineer Nguyen Tien Hung, an electric expert in control. In addition, the asphalt pot is also broken from the cover of glass cotton to the inner heating unit. After many efforts, the group has replaced all and found solutions to use FO, an oil waste, to save operating costs.

Five months later, the batching station system was completed and handed over to Nam Dinh Urban Company. The money from the contract not only helps to pay the debt but also brings the first balance, enough for Binh Binh to buy an old motorbike, his largest asset at that time.

In the early 1990s, when the demand for maintenance and upgrading of roads increased, the research team of the University of Transport was determined to build the first hot plastic concrete mixing station of Vietnam. The group combined with the 1-5 motorcycle mechanical factory is built with a capacity of 25 tons/hour with a semi-automatic operation mechanism.

The first concrete mixing station was researched and designed in the condition that no customers have ordered, the confidence of society has not been built, and the Ministry of Transport has many doubts about technology. At the same time, the 1-5 automobile mechanical company is facing the status of moderate operations, even facing the risk of bankruptcy, the project development funding source becomes limited.

At that time, 246 transport construction company ordered the first hot plastic concrete mixing station with 1-5 automobile mechanical company, providing an important opportunity for the project. However, the group still faces many difficulties, is forced to take advantage of components from old machines and self -research to create parts that cannot be purchased. “The group uses the hydraulic cylinders of the excavator and then renovated into the inflatable part, while the electric valve must be completely new,” PGS recalled.

After 9 months of manufacturing, the first concrete mixing station was completed. This station is designed in a vertical model and operates in the form of forced cycle. The first concrete station was installed on a fixed concrete pillar, guaranteed to be firm but difficult to install, not moving and time -consuming, “takes 3 months, the new group successfully installed the first concrete station on the trying concrete pillar Dinh “, Assoc. Prof. Binh said.

Recognizing this limitation, the team started looking for alternative solutions. When designing the second mixing station with a capacity of 30 tons/hour with automatic control system, engineer Nguyen Binh and Assoc. “Steel foundations have mobile advantages, easy to install but easy to flip and uncertain,” said Associate Professor Binh. The group must calculate and test in different weather conditions. Therefore, when the mixing station is 30 tons/hour, the group still uses concrete pillars for installation.

In 1994, the new group officially introduced the floating steel foundation system. This is a structure consisting of two large steel blocks in the form of boxes with bending, pressing, elastic force and can be moved. In addition, the group also uses anchor cord to support the fixing of the mixer. This option not only saves costs but also shortens the installation time. 40 tons/hour station with floating steel foundation was then installed for the construction of Hanoi – Xuan Mai route, operating without any errors.

The steel foundation system for hot plastic concrete mixing station was later displayed for the first time at Giang Vo International Exhibition Fair in 1994, and then at the 9th International Fair of Construction Machinery, in Beijing Year of the Year 2007.

To achieve those results, the team worked 13-14 hours/day. “In addition to the design hours, the group must go to the construction site with workers,” said Assoc. Prof. Binh shared. He said that the welded steel piece was shot into the heel, took 3 months to recover. Engineer Nguyen Tien Hung also had an accident when the asphalt cooker exploded, causing severe legs to burn.

After the initial success, the group continued to research and raise the capacity of the station to 60, 80, then 120 tons/hour in 2014. The manufacturing cost was much cheaper than import stations of the same capacity.

Starting from the work of restoring an abandoned hot concrete mixing station in Quang Ninh, the research team of Assoc. Prof. Nguyen Van Hop and Assoc. More than 500 stations were manufactured, capacity of 30 to 120 tons/hour.

According to Assoc.Prof.Dr. The socio -economic scene at that time. It saves costs, does not have to import equipment from abroad, and provide good quality products for many construction works. This is a typical research project of the University of Transport, contributing to the development of the Vietnam Construction Industry in the early stages of innovation. “The work has made a great deal,” said Assoc.

The research was the first prize in the Vietnam Creative Award (VIFOTEC) in 1997.