- Jun 11, 2018 -
The Store Baelt Bridge is built on the 18-kilometre wide Great Belt between Denmark's Zealand and Funen Islands. The suspension bridge on the bridge is 1,624 meters long and is the longest in the world. One of the suspension bridges.
The bridge is a road and railway dual purpose bridge. The 6.6-kilometer-long Western Bridge from Finying Island to Slope Log Island was completed in July 1996. The tunnel to be used for the East Bridge from the island of Zealand to Sloping Island has been opened in the summer of 1995. Dongqiao’s highway bridge is on the water. In this part of the bridge, there is a suspension bridge with a height of 254 meters; the span between the two towers is 1,624 meters, second only to the Akashi Kaikyo Bridge under construction in Japan; the height of the bridge hole is 65 meters, can pass any big wheel. Suspension bridges use 19,000 tons of wire rope with a main cable diameter of 85 cm.
The seawater environment is one of the most severe environmental conditions for concrete. Concrete structures need to withstand mechanical and man-made strength requirements. The structure is prone to failure. At the same time, concrete structures used in this environment can also suffer from freezing, wind and waves. The effects of various natural factors such as water quality tend to damage the concrete and shorten its durability. The problem of the mechanical properties and durability of the existing ordinary concrete structures in this environment is becoming increasingly acute, and they have to spend a huge amount of money every year to repair them. This problem has caused worldwide concern in the engineering community.
For the first time, the Great Belt Belt project in Denmark proposed a service life of 100 years, which guarantees its mechanical properties and stipulates that steel bars must not begin to rust during the 100-year life cycle. To this end, a large number of special studies have been conducted in advance and strict technical standards for concrete have been stipulated. The provision of a certain amount of micro-silica fume (silica fume) and fly ash is required to ensure the low permeability of the concrete; it is guaranteed by the bleed air and bubble quality control. Its frost resistance; Wear resistance by adding micro-silica fume (silica fume) (anti-sea ice milling); By limiting the active aggregate content, limiting the total alkali content, adding micro-silica fume (silica fume) and Fly ash prevents alkali-aggregate reaction; resistance to sulphate attack - use of sulphate-resistant cement and addition of micro-silica fume (silica fume); use of low-heat cement, addition of micro-silica fume (silica fume) and fly ash reduction The heat of hydration is used to control the thermal stress cracks inside the concrete during pouring. The actual concrete mix used for the preparation of concrete 7 days compressive strength of not less than 35Mpa, 28 days compressive strength of not less than 50Mpa.