Known as the "world's first hydropower project", the Three Gorges Water Control Project is the largest in the world with its large scale and complex technology.
Including the reservoir resettlement project, the Three Gorges Project is expected to have a total investment of 654.38+08 billion yuan and a construction period of 654.38+07 years, making it one of the largest projects in China.
It is obviously not feasible to rely on "hard work" and engage in "crowd tactics" for such a huge and complicated project.
The technical route of the Three Gorges Project takes the road of integration and innovation. Li Yongan, general manager of Three Gorges Corporation, told reporters that the Three Gorges Project has absorbed and adopted the most advanced technology and equipment in the world, and the introduction, digestion, absorption and re-innovation run through the whole process of the Three Gorges Project.
The Three Gorges Project has achieved fruitful scientific and technological achievements: 14 national scientific and technological progress awards, more than 200 provincial and ministerial scientific and technological progress awards, more than 700 patents, 100 engineering quality and technical standards, and 100 world records. Therefore, it can be said that the Three Gorges Project is the biggest innovative project.
How did the miracle of the crack-free dam be created?
On May 20th, Academician Pan, the leader of the quality inspection expert group of the State Council Three Gorges Project, said in the Three Gorges dam area: "Now the right bank dam has reached its peak. After many inspections, no cracks were found in more than 4 million cubic meters of concrete ... Today, we can announce that the right bank dam of the third phase of the Three Gorges Project is a dam without cracks, and the builders of the Three Gorges Project have written records in the history of dam construction, creating a miracle in the history of architecture. "
The total amount of concrete in the Three Gorges Project is 28 million cubic meters. Such a huge concrete pouring volume ranks first in the world's water conservancy projects.
The Three Gorges Dam is the most basic and core part of the Three Gorges Project. Cao Guangjing, deputy general manager of Three Gorges Corporation, said that the rapid construction technology of dam concrete is a typical example of integrated innovation of Three Gorges Project and a technological revolution of dam concrete pouring.
The Three Gorges Project took the lead in using crushed granite as the artificial aggregate of concrete in China, and used Grade I fly ash with excellent performance as the concrete admixture for the first time, and invested millions of yuan to study the mix proportion of concrete, including further improving the high-performance admixture, so as to make the comprehensive performance of concrete reach the optimal level. After parallel testing by several authoritative research institutions and the testing center of the head office, the optimized water consumption per unit of mass concrete mixture ratio is only about 90 kg/m3, reaching the world advanced level.
Temperature control and crack prevention of mass concrete is another key and difficult point in dam construction, because when the belt conveyor transports precooled concrete, the temperature will rise greatly, especially in the high temperature season in summer, the temperature of concrete will rise by about 1℃ for every transportation150m, which makes it more difficult to control temperature and crack. The builder of Three Gorges Project pioneered the secondary air cooling technology of concrete aggregate. In midsummer, all the concrete produced in the mixing plant is precooled to 7℃, and each part of concrete is carefully managed, and targeted "personalized" temperature control measures are taken to effectively control the maximum temperature of concrete.