Dual benefits in investing in the production of new technology construction materials

Reinforced concrete structures such as seaports, earth retaining walls, coastal erosion control, breakwaters, coastal road bridges, etc. are all subject to salt corrosion. Therefore, the research and production of materials adapted to salty environments play an important role in ensuring stability and increasing the life of the structures.
Increasing the marine economy
Currently, localities are implementing many reinforced concrete (RC) infrastructure projects, such as transportation, seaports, especially recently to adapt to climate change, rising sea levels, irrigation works, sluice gates, sluice gates, embankments, breakwaters, etc. are being urgently built to meet the needs of coastal economic development.
According to Dr. Dinh Anh Tuan – Director of the Institute of Pumps and Hydraulic Equipment, in Vietnam, reinforced concrete was put into use by the French in the late 19th century, but it was not until after 1960 that the volume of structures made of this material in the marine environment increased significantly.
All coastal structures built in the period 1960 – 2010 were applied according to conventional construction standards, paying little attention to anti-corrosion issues to ensure the sustainability of the structures, resulting in a low lifespan for many structures in the marine environment. Many reinforced concrete structures with a service life of 10 – 15 years have been severely corroded and destroyed, requiring a cost of about 40 – 70% of the cost of new construction for repair and protection.
The sea is a highly corrosive environment for concrete, and structural reinforced concrete accounts for over 70% of construction. Meanwhile, Vietnam’s marine environment is more corrosive than the marine environment of many countries in the world due to high temperature, humidity, high humidity, high Cl- concentration, and salty water and aggregates. Therefore, anti-corrosion and construction protection must be based on world technology and must be associated with the actual conditions of Vietnam.
“The design and construction of concrete and reinforced concrete according to current regulations is expected to ensure structural durability of 50 – 60 years, but in reality, most of the surveyed works only reach 20 – 30 years, many works are severely damaged after 7 – 15 years. The rate of corrosion is alarming, causing damage faster than the ability to repair, which is very costly” – Dr. Dinh Anh Tuan said.
According to experts, currently, more than 50% of reinforced concrete structural components in coastal works are corroded, severely damaged or destroyed after only 10 – 30 years of use. The decline in the life of reinforced concrete structures is a matter of great concern.
Sustainable development
Chairman of the Board of Directors of the University of Construction Technology Investment and Development Joint Stock Company (Nucetech) Nguyen Van Khanh said that the corrosion of steel in concrete has many causes, but the main agents are chemical and electrochemical corrosion. Normally, when the steel is corroded (rusted), the volume increases, causing cracks in the protective concrete layer, further developing the corrosion process leading to structural damage.
“There are many solutions to limit corrosion of steel in reinforced concrete structures, such as increasing the thickness of the protective layer of steel, using high-grade concrete to increase density, using waterproof paint… but all of them increase costs” – Mr. Nguyen Van Khanh said.
Currently, scientists have successfully researched and produced FRP fiber reinforcement to replace steel reinforcement in reinforced concrete structures, called FRP composite fiber reinforced concrete. FRP (Fiber Reinforcement Polymer) bars are made of continuous fibers, impregnated in polymer resin binders, binders are usually epoxy, polyester, vinylester.
According to the representative of Vietnam Fiber Reinforcement Polymer Joint Stock Company (FRP Vietnam), glass fibers, basalt fibers, aramid fibers, carbon fibers can be used to make FRP bars. Normally, people often use glass fibers to create and use in concrete structures, because it not only meets the requirements of bearing capacity but also has a more reasonable price, while Vietnam has a rich source of white sand to create glass fibers – the main material for producing FRP bars.
In addition to FRP fiber reinforced bars that have been and are being applied in protecting works and islands, the development of new construction materials for coastal works can be mentioned as HPC Concrete – High Performance Concrete, HPC and FRP concrete piles, submerged breakwaters…
Experts and scientists all agree that an effective solution to help coastal works increase their lifespan in the context of increasingly severe climate change today is to strengthen cooperation activities, produce new, smart, energy-saving construction materials with high economic efficiency and environmental friendliness. This aims to reduce greenhouse gas emissions, environmental pollution and the problem of increasing natural disaster risks, especially in provinces in the upstream areas and important coastal areas.