n the early years, bridge engineering was mostly about concrete Bridges, steel Bridges and steel-concrete combination Bridges. After a period of use, the following problems often occurred:
(1) plate beam longitudinal cracks, internal steel corrosion occurs seriously;
(2) the concrete of partial plate beam appears serious corrosion and mildew;
(3) appear on the bridge network crack;
Faced with these traditional problems, people begin to look to composite materials for solutions. Composite materials began to bond with the bridge.
FRP materials have been used in bridge engineering since 1970s. Britain, the United States and Israel were the first to use the new material as a major component in building structures and bridge structures.
In 1992, in the course of Aberfeldy golf club in Scotland, England, an all-frp cable-stayed footbridge was built.
In 1996, the Stork Bridge, the world's first road Bridge using FRP cables, was built in Switzerland.
China is one of the early countries to study and apply glass fiber composite materials in building Bridges. In 1982, the world's first glass fiber composite road bridge built in miyun, Beijing was a single-span simply supported box girder bridge, with a span of 20.7m and a width of 11.8m. Guanyin bridge in chongqing is also made of glass fiber composite materials, with a span of 72.8m and a total length of 167m.
Now composite materials have been involved in engineering in a larger scope after a long period of practice and improvement. Construction technology and composite structure have undergone a series of upgrades.
Traditional composite sandwich material components are prone to surface layer and core material interface stripping failure in the process of manufacturing and service, which seriously restricts its light weight and high strength. Now the three-dimensional solid sandwich structure of composite material is adopted, which is composed of a number of three-dimensional solid composite material collision prevention segments. Each segment is composed of foam sandwich composite material reinforced by hollow lattice webs. Composite material anti-collision system can prolong collision time, dissipate collision energy, and effectively reduce collision damage of ships. Langqi minjiang river bridge, wulong river bridge and parrot island Yangtze river bridge are all constructed with composite sandwich materials.
Carbon fiber composite (CFRP) is a new strengthening technology which is widely used in bridge strengthening projects. It also shows that composite materials are playing an increasingly important role in Bridges.
Carbon fiber sheet is mainly used for strengthening the basic members and joints of concrete Bridges to improve the flexural capacity, shear capacity and axial compressive capacity of compression members, and to improve the stiffness and ductility of the members. In addition, it can be used to control the development of crack width of concrete members. Carbon fiber sheet (especially carbon fiber cloth) is light in weight and thin in thickness, and has certain flexibility.
Composite materials play a more and more important role in bridge engineering. This is closely related to the hard work of thousands of experts and scholars who study composite materials day and night. I would like to thank all the researchers for actively promoting the development and progress of composite materials.