1、PDF外文：http:/ 1 Epoxy asphalt concrete paving on the deck of long-span steel bridges Under the influence of traffic load, wind load, temperature change and other factors, stress and deformation of paving system is very complicated when paving the long-span orthotropic steel bridge deck.
2、So the weight of the paving structure should be very light and the paving material should have the properties such as high bonding power, impermeability, and so on. At present, paving projects are primarily classified into four types: Gussasphalt project, mostly used in Germany and Japan； mastic asp
3、halt project, typically in England； stone mastic asphalt (SMA), a kind of modified asphalt lately used in Germany and Japan； and epoxy asphalt, mostly adopted in USA. Epoxy asphalt concrete is a kind of high strength and flexible material by adding thermosetting epoxide resin and solidified agent in
4、to asphalt. As a paving material, epoxy asphalt is mainly applied for steel bridge deck in USA, Canada and Australia, especially in USA. But this material has never been used for paving bridge deck in China until its application in the SNYRB. These years, the construction of long-span bridges
5、in China has developed very fast. Many paving techniques of Japan and England have been adopted in constructing bridges. However, these techniques are not completely applicable for the particular climate and traffic conditions in China. Furthermore, the steel girder box structure, once universally u
6、sed by foreign countries, has been applied in long-span bridges recently constructed in China, and the highest temperature of the paving of bridge deck in most areas of China can reach 70 . So the paving material must possess the higher temperature stability. The paving layer of many bridges was dam
7、aged shortly after being put into use. In fact, the paving technique of steel bridge deck depends to a large extent on the structure of steel bridge deck and natural environment. Deep and systematic research on paving of steel bridge deck is very limited in China. In this paper, the composition desi
8、gn of epoxy asphalt concrete, its characteristics and service performance of the mixture, bond performance of epoxy asphalt concrete with steel plate, the fatigue test of complex girder formed by the steel plate and epoxy asphalt concrete, are firstly and systematically studied. In addition, epoxy a
9、sphalt concrete is successfully applied in the paving of steel bridge deck of the SNYRB, and the paving layer of the bridge has shown an excellent performance after it has 石家庄铁道大学四方学院毕业论文 2 been put in use for more than one year. According to different purposes, epoxy asphalt can be cla
10、ssified into two types: material for bonding layer (type Id) and for binder (type ). Commonly, epoxy asphalt is made out of two components: component A (epoxy resin) and component B (homogeneous complex composed by petroleum asphalt and solidified agent). If the two components have bad compatibility
11、, medium should be added. Requirements of epoxy asphalt concrete for aggregate are rather strict. Aggregate should be clean, rigid, wear proof and non-acid minerals with 100% broken surface. Its favorite shape should be a cube. Light color is better to reduce the heat caused by solar radiation in hi
12、gh-temperature seasons. Limestone flour is used as filling mineral and contains at least 90% limestone, but none active lime should be used. From the experience of key projects and general consideration of all kinds of test index (most tests are Los Angeles abrasion tests), basalt from the Huashang
13、Mountain in Jurong is chosen as the aggregate for the SNYRB. The results for all characteristic tests are as follows: Los Angeles abrasion loss is 10.6% (after 500 rotation cycles), the crash value is 8.6%, the polishing value (psv) is 52, water-absorbing capacity is 1.0%, compression strength is 13
14、8 MPa, binding power is 4-level, sand equivalent is 50 and the slender and flat particles form a proportion less than 2.65%. The fatigue life-span of the paving layer could be extended by using fine graded aggregate. However, macroscopic roughness would be reduced accordingly and so would the slidin
15、g strength of pavement under moist conditions. After a lot of comparison with the test results, gradation and the forbidden zone of Superpaves aggregate gradation are shown in Fig. 1 . Fig. 1. Grading design of aggregate for the SNYRB. 石家庄铁
16、道大学四方学院毕业论文 3 From the investigation on failures, the loss of the binding power between the paving layers and the steel plate generally takes place between the asphalt mixture and the rustproof layer for the deficiency of binding intensity of the binding layer. Normally, the material fo
17、r the binding layer is a heat-sealing binding material, solvent bonder or thermosetting binding material. Based on the results of tests, epoxy asphalt, a kind of thermosetting adhesive material, is chosen for the binding layer for the SNYRB. Epoxy asphalt has great intensity and elongation capacity.
18、 At 23 , the strength of extension is 8.1 MPa,and the breakage elongation percentage is 232%. In the shearing test by steer plate, the shearing strength is 6.84 MPa at 19 and 100 MPa at 60 . The results show that the intensity of epoxy asphalt is greater than that of any other binding material
19、s. To compare the bond strength between the epoxy zinc primer paint or the inorganic silica acid zinc paint and the paving layer, the steel plate is coated respectively with these two rustproof paints in the tension test. Tests are carried out at low (02 ), room (232 ) and high temperatures (6
20、02 ), respectively. The values are 7.13, 1.55 and 0.92 MPa for inorganic silica acid and zinc paint respectively and they are 4.24 and 2.23 MPa for the failure plane taking place between the bonder and elongation point and not less than 0.97 MPa for epoxy zinc primer paint. It indicates that epoxy z
21、inc primer paint has better binding strength with the paving layer. In addition, all the failure planes of the sample have not occurred between the two paving layers, which shows that the interlayer binding strength is enough and reliable when the paving of the bridge deck is spread with two layers
22、respectively. The optimum asphalt applied level for the epoxy asphalt mixture was determined by the Marshall test and other material performances were made through the tracking test, soaking Marshall test and so on. To further understand the performance of the epoxy asphalt mixture, several other ki
23、nds of asphalt mixtures were tested for contrast. The void ratio is an important index for the composition design of the epoxy asphalt mixture. The required void ratio is 3% due to the characteristics of the epoxy asphalt mixture. Considering that the difference exists between the solidification pro
24、cess in laboratory and paving process in the spot, the optimum ratio of stone to oil was determined to be 6.7% after the performance test on the unsolidified sample. The intensity of epoxy asphalt concrete was measured by the Marshall test, splitting test, bending test and compression test, respectively. The test results were compared with Gussasphalt concrete, SMA and dense-graded modified asphalt concrete.
