Study On Steel Bridge Deck Gussasphalt Low-temperature Index And Pavement Technology In Cold Regions

Gussasphalt is one of the most widely used steel bridge paving materials with its excellent low-temperature performance,water resistanc,fatigue resistancec and the ability to follow the deformation orthotropic steel bridge decks.At present,the gussasphalt pavement is widely used in the steel bridge deck pavement in southern China,and the effect is good.However,this bridge deck pavement technology is still in the initial stage in the northern cold regions.There are still many gaps in the design,construction and testing standards of steel bridge deck gussasphalt pavement in low temperature environment,which has brought great inconvenience to its popularization and use in the northern cold regions.Therefore,based on the steel bridge deck paving engineering of the southern city in Ji Ning,combined with the existing research results and considering the climate difference between North and south,this paper deeply studied the technology of steel bridge deck gussasphalt pavement in cold regions.The main contents of this paper are as follows:(1)At the beginning of study,the type and disease status of steel bridge deck gussasphalt pavement at home and abroad were investigated,aiming to analyze the reasons of common diseases and recommend reasonable pavement structure.(2)According to the results of climate survey in the location of the project,the temperature field of steel bridge deck pavement was studied by using finite element software.Then the working temperature range of pavement was proposed,which laid a foundation for further research.(3)The low temperature performance of gussasphalt with 6 different gradations and mixing ratio of TLA was studied by low temperature bending test and low temperature split test and bending creep test.Based on the analysis of the correlations and sensitivities of three indexes,the low temperature evaluation index and standard of gussasphalt in cold regions were proposed.(4)According to the test results of fluidity,high temperature performance,low temperature performance and corresponding technical requirements,this paper recommended the reasonable design scheme of gussasphalt in cold regions.(5)Through bending fatigue test,the fatigue characteristics of GA under different stress ratios and asphalt content were studied.According to the fatigue performance curve,the prediction equation of GA fatigue life is established under the reasonable design scheme,and a correction equation based on the actual work environment was proposed.(6)The high and low temperature performance and freeze-thaw resistance of gussasphalt composite paving systems were systematically studied.And then the performance of the three types of waterproof adhesive materials was compared and analyzed through the low-temperature flexible test and the shear and pull-out tests,aiming to recommend waterproof adhesive materials suitable for steel decks in cold regions.(7)This paper studied the problem of superheat and low oxygen aging of gussasphalt in COOKER transport trucks,and put forward the technical requirements for the storage time of gussasphalt in cold regions.