Analysis on the development of bridge coatings and

Analysis on the development of bridge coating and coating technology in China

analysis on the development of bridge coating and coating technology in China

October 30, 2012

[China coating information]

Li Minfeng (fire and corrosion prevention branch of China Steel Structure Association, Shanghai 200136)

QIAN Shengjie (Shanghai Xianing New Material Technology Co., Ltd., 200090)

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Abstract: This paper expounds the development trend of bridge construction in China, as well as the development process of bridge coating and coating technology in China. The development characteristics of bridge coatings in China are analyzed. This paper introduces the work of energy conservation and emission reduction of bridge coatings in China, as well as the domestic and foreign standards related to bridge heavy-duty anti-corrosion coatings and coatings

key words: Bridge coating; Supporting coating; Painting technology; Domestic and foreign standards

Chinese Library Classification Number: tq639 document identification code: a article number: (2011)

1 development trend of bridge construction in China

after 30 years of development after reform and opening up, bridge construction in China has reached the commanding height of the world bridge industry in terms of material specifications, design concepts and industrial manufacturing. According to the statistics of the International Association of bridge and structural engineering in 2010, there are 48 bridges in China, accounting for 43% of the 111 bridges of 11 types. Among the top 10 sea crossing bridges in the world, China accounts for 4 seats, as shown in Table 1

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Table 1 China's four major sea crossing bridges

in the past three years, with the implementation of a new round of national infrastructure construction plan, China's bridge engineering construction has entered a spring of rapid development. According to statistics, by the end of 2009, there were 620000 highway bridges in China, with 27.26 million M, an increase of 8% over 2008; There are more than 140 bridges with a main span of more than 200m in China. By the end of June 2010, there were 65 bridges under construction in 19 provinces and cities in China, and the overview of 5 bridges under construction (in order of cost) is shown in Table 2

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Table 2 overview of 5 major bridges under construction in China

including railway and highway bridges (including steel structures and concrete bridges). The Hong Kong Zhuhai Macao Bridge ranked first is the world's longest cross sea bridge, which can resist an earthquake of magnitude 8. At magnitude 16, we selected the on-site interviews of Jinjin medical, denipe, Lubrizol, Solvay and DuPont to publish the gale. The steel consumption is about 500000 tons, equivalent to the steel consumption of 11 "bird nests", and the service life of the steel structure is 120a

China's steel structure factories have also undertaken many foreign-related bridge projects, and the steel structures and the heavy-duty anti-corrosion coatings used are all made in China. For example, Shanghai Zhenhua heavy industry has undertaken the Incheon bridge in South Korea, Oakland Bay Bridge in the United States, Hardanger bridge in Norway and England bridge in Britain; Chinese construction company undertook the Alexander Hamilton bridge project in the United States

foreign commentary: it took only 20 years for China's bridge industry to complete the development performance of Europe for decades. In the next 20 years, China's bridge construction market will undoubtedly be an enviable stage

2 development history of bridge coatings and coating technology in China

the development of bridge coatings and coating technology in China has experienced the following three stages:

first, the initial stage (1956~1979): at that time, the Academy of Railway Sciences jointly developed and developed bridge coatings with domestic paint plants such as Tianjin lighthouse paint factory, which were used on Wuhan Yangtze River Bridge and Nanjing Yangtze River Bridge. The paint type is red lead antirust primer, alkyd finish, and a small amount of phenolic paint, polyurethane paint, etc

second, development stage (1981-1999): Shanghai Kailin paint factory and others developed bridge supporting coatings based on epoxy zinc rich primer, epoxy micaceous iron intermediate paint and chlorinated rubber finish, which were used on Shanghai Nanpu, Yangpu and Xupu bridges, making a good start for the development of heavy-duty anti-corrosion coatings for bridges in China

third, the stage of rapid development (2000 ~ now): at the beginning of the 21st century, multinational coating companies such as Hempel, IP, Kansai, sigma, etc. have established factories in China in the form of sole proprietorship or joint venture, bringing advanced bridge coating and coating technology into China, promoting the rapid development of bridge coating in China, and making the consumption of bridge coating in China reach the peak, Moreover, the progressiveness of bridge coating and its supporting technology has also reached the world leading stage. Specific examples are as follows:

(1) polysiloxane finish. AkzoNobel (Suzhou) industrial paint company and Jotun (Zhangjiagang) paint company have successfully applied high-performance polysiloxane topcoats to Chongqing Caiyuan dam bridge and Chaotianmen Bridge respectively. The supporting scheme adopted at that time was: inorganic zinc silicate primer + epoxy micaceous iron intermediate paint + polysiloxane finish paint, and remarkable achievements were made in the coating process

(2) see Table 3 for the new varieties of anti-corrosion coatings developed by Beijing Aviation Materials Baimu new materials technology Engineering Co., Ltd. and the application performance of bridges

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Table 3 - new varieties of anti-corrosion coatings and bridge application performance developed by Beijing hangcai Baimu new material technology Engineering Co., Ltd.

(3) the bridge heavy-duty anti-corrosion coatings developed by COSCO Kansai coating company have excellent anti-corrosion properties. In recent years, they have supplied the following 1million tons of steel structures: Sidu River Bridge, Daning River Bridge, Nanjing Dashengguan Yangtze River Bridge Qingdao Bay Bridge, Yongjiang Mingzhou bridge, Yaojiang Wantou bridge. In the second half of 2010, COSCO Kansai undertook the supply of bridge coatings for Wuhan Erqi Yangtze River Bridge and Anqing Yangtze River Bridge

according to the actual situation of bridge engineering in China, the following three supporting schemes are generally adopted for new bridges:

the development of extruder industry still has a large market space (1) concrete structure: sealing paint: epoxy sealing paint or silane impregnant; Intermediate coat: epoxy intermediate coat; Topcoat: acrylic polyurethane topcoat, fluorocarbon topcoat, polysiloxane topcoat in atmospheric environment; Splash zone or dry wet alternate zone: epoxy finish paint, etc

typical engineering cases include the concrete structure of Xihoumen Bridge, one of the Zhoushan Ningbo mainland Island connecting projects, which adopts the supporting coating of COSCO Kansai (Shanghai) coating company:

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the supporting coating of COSCO Kansai (Shanghai) coating company

the coating area of the project is 20000m2, which was completed in March 2009

bridges that have successfully applied similar supporting coatings include Hangzhou Bay Bridge, Qingdao Bay Bridge, the Yellow River Bridge, etc

(2) steel structure: all adopt heavy-duty anti-corrosion coating. Primer: inorganic zinc rich primer, waterborne inorganic zinc rich primer, epoxy zinc rich primer; Intermediate paint: epoxy micaceous iron intermediate paint, epoxy zinc phosphate intermediate paint; Finish: acrylic polyurethane finish, fluorocarbon finish, polysiloxane finish. Steel structure bridges that are all equipped with heavy-duty anti-corrosion coatings include Nanpu Bridge, Runyang Bridge, Sutong Bridge, Caiyuanba bridge, Hong Kong stonecutters bridge, etc. It is worth mentioning that the inner side of the steel box, the air nozzle and other parts adopt the method of supporting coating for corrosion prevention

(3) steel structure: arc spraying zinc, aluminum, zinc aluminum alloy, zinc magnesium alloy is used as the primer. Most of the supporting coatings are epoxy special sealing paint; Epoxy micaceous iron intermediate paint; Acrylic polyurethane finish, fluorocarbon finish, polysiloxane finish

this supporting scheme is adopted for Xiamen Zhangzhou bridge:

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the supporting coating scheme for Xiamen Zhangzhou bridge

this supporting coating scheme has also been successfully applied to Hong Kong Tsing Ma bridge, Zhoushan Taoyaomen bridge, Wuhan Junshan bridge, Guangdong Hainan railway trestle, Wuhan Hanyang Luo Bridge, etc

according to incomplete statistics, the anti-corrosion method of using arc spraying zinc, aluminum, zinc aluminum alloy, aluminum magnesium alloy as the bottom layer of heavy-duty anti-corrosion coating accounts for 35% of the anti-corrosion of bridge steel structures

3 characteristics of the development of bridge coatings in China

bridge coatings belong to heavy-duty anti-corrosion coatings. The supporting coating of heavy-duty anti-corrosion coating should have the following characteristics: it can be used for a long time under harsh conditions; Good adhesion and strong professional function; Thick film spraying can be realized; Excellent construction conditions

driven by the rapid development of the bridge industry, the output of bridge coatings in China has increased and the development momentum is strong. In 2010, the total output of coatings in China exceeded 9million tons (ranking first in the world), including 2.4 million tons of industrial anticorrosive coatings, accounting for 27%, 1.32 million tons of heavy-duty anticorrosive coatings, accounting for 55%, and 190000 tons of bridge anticorrosive coatings, accounting for 15%

bridge coatings rank third in the share of heavy-duty anti-corrosion coatings after the shipbuilding and petrochemical industries. According to the survey of medevac consulting, the output and growth rate of bridge coatings in China from 2007 to 2010 are shown in Table 4

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Table 4 output and growth rate of bridge coatings in China

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Table 5 structure and composition of bridge coatings in China

it is worth mentioning that in the practice of bridge construction, China has gradually improved the anti-corrosion protection of bridge concrete. Among the bridge coatings, the share of concrete coatings is 25% - 30%, and has a trend of increasing year by year

4 energy saving and emission reduction of bridge coatings in China

in recent years, in the process of the development of bridge coatings in China, energy saving and emission reduction has been taken as the main direction, and the following work has been done:

(1) environmental friendly bridge coatings have been adopted. In bridge coatings, red lead paint has long been eliminated, and pigments and fillers containing toxic and harmful heavy metals such as lead, mercury and chromium have been stopped. For example, develop "flake zinc" instead of "powder zinc"; The zinc powder in the primer of inorganic zinc rich workshop is replaced by an appropriate proportion of iron phosphorus powder to achieve the purpose of saving resources. In addition, the resin types of bridge anti-corrosion coatings have been selected and modified to make them more in line with environmental protection requirements. For example, before 2005, chlorinated rubber topcoat was the first choice of bridge supporting coatings, accounting for more than 70%. According to the relevant provisions of Montreal regulations, in order to protect the atmospheric ozone layer, China has gradually reduced the amount of chlorinated rubber finish, which has been completely replaced by polyurethane finish, fluorocarbon finish and polysiloxane finish

(2) vigorously promote high solid coatings and solvent-free coatings. At present, bridge coatings are mainly solvent based coatings. Therefore, reducing the VOC content of solvent based coatings and improving the solid grade of coatings are the focus of environmental protection work of bridge coatings. According to statistics, at present, high solid coatings account for about 40% of the total amount of bridge coatings in China, and solvent-free coatings account for about 5%, which is higher than that in previous years

(3) accelerate the development of waterborne bridge coatings. As early as 1995, when the Xupu Bridge was built in Shanghai, the American ic531 waterborne inorganic zinc rich coating was used as the primer under the designation of the owner and the design unit, which made a good start for the application of waterborne bridge coatings in China. Later, the waterborne inorganic zinc rich primer developed by Shanghai menpley new materials company was successively applied to the steel box girders of Yichang Yangtze River Bridge, Zhejiang Tongwamen sea crossing bridge and Shandong Yellow River Bridge, and matched with the domestic solvent based epoxy micaceous iron mid coat, polyurethane finish and fluorocarbon finish, showing great advantages in corrosion resistance and construction performance. Recently, the waterborne fluorocarbon coating developed by Dalian Zhenbang coating company has been successfully applied to two river crossing bridges in Harbin, with a total of 5~6t of supporting coating. Although the share of waterborne bridge coatings in China is less than 3%, it is believed that it will develop rapidly in the "12th Five Year Plan"

(4) develop new processes and technologies of bridge coating for energy conservation and emission reduction. The coating also involves energy conservation and emission reduction. In recent years, large bridge manufacturing plants such as "Wuchang shipbuilding industry", "Zhenhua Port Machinery", "Shanqiao", "Baoqiao" have set up steel pretreatment lines, which are specialized in