(Construction Newspaper) - Recently, Ecoba Vietnam Joint Stock Company ended the placement of mass concrete for the foundation tower of Office B tower of Lotte Mall Hanoi project with a total volume of 8,039m3 for 54 days. This is a new step in the application of massive concrete - environmentally friendly green materials in the construction.

According to research, the concrete structures are considered as large blocks when they are of sufficient size to cause tensile stress so that when placing concrete, the heat generated by the hydrated cement can exceed the tensile strength to crack the concrete. Therefore, the measures to prevent cracks are required. Th experts at Institute of Concrete Specialization - Institute of Construction Science and Technology (Ministry of Construction) have collaborated with Lotte E&C Research and Development Institute of Lotte Engineering & Construction Co., Ltd to develop environmentally friendly concrete in which 50% of the cement is replaced by a mixture of fly ash and finely ground blast furnace slag.

Overview of Lotte Mall Hanoi project, constructed by Ecoba Vietnam, in package B, in the process of placing foundation with large concrete.

The results of research in the lab show that this type of concrete develops very well at long age, after 6 months, it can reach and exceed the strength of concrete using 100% cement. When using 20% ​​fly ash and 30% finely ground blast furnace slag instead of cement, the maximum temperature in the 1m cube test block has been reduced by 10 degrees Celsius. At the foundation block, the site showed that the temperature at the center of the foundation block did not exceed 70 degrees Celsius, meeting the technical requirements of the project.

The application of this type of concrete is very efficient and, and also, effectively using two types of industrial waste, namely fine crushed blast furnace slag and fly ash. The experts believe that the use of finely ground blast furnace slag in combination with fly ash will increase the consistency, good waterproof ability, long-term strength, reduce hydration heat, improve the environmentally friendly level and lower cost compared to using cement or just using cement with fly ash.

In order to further promote the application of new technology solutions, environmentally friendly, ensure quality and reduce construction costs, it is essential to have the coordination of stakeholders such as the Employer and design, construction contractors. In addition, an indispensable part is the support for the State's policy in continuing to invest in researching, compiling and issuing new technical documents and standards in accordance with Vietnamese conditions and integration with the world level.

Engineering team of Ecoba Vietnam participated in the construction of Lotte Mall Hanoi project

Source: Construction newspaper