| Asphalt pavement cracking and water damage are common pavement diseases in the high temperature and rainy area of southern china.Especially in the south of China are mostly located in the temperate monsoon climate,humid and rainy day and temperature changes significantly,low temperature cracking of asphalt pavement reflection crack or cracks caused by semi-rigid base will cause rain or snow in the pavement structure in the base the results of research at home and abroad to soften,and combined with the climatic features of Jiangxi province and the traffic situation,through the research between asphalt layer and semi-rigid waterproof layer material,design and construction technology,improve and strengthen the coordination between the semi-rigid asphalt pavement,to solve the rain erosion,semi-rigid asphalt pavement reflection crack and transverse passage etc.,.In order to improve the asphalt pavement structure,enhance its waterproof and anti-crack ability,combined with the characteristic of Jiangxi climate and traffic conditions in the top layer and the surface layer between the paving layer thickness is less than 2% and the void ratio in asphalt mixture layer 10mm-15 mm.First of all,the drainage asphalt mixture pavement void ratio is relatively large,in order to prevent rain or snow into the middle layer or semi-rigid base,so the gap of waterproof and ant-crack layer rate is relatively small.Waterproof anti crack layer mixture composed of aggregates,mineral powder,SBS modified asphalt and stone gold basalt fiber composition.A special role in the pavement structure determines that it is mainly composed of limestone ore and the modified asphalt composition,its typical characteristic is the particle size in the material,set stone below 5mm ratio,a small percentage of voids.The basic properties of the raw materials are tested by using appropriate waterproof and anti-cracking layer materials.According to the AC-5 asphalt mixture specifications,raw materials through the screening test to determine the initial grading,waterproof and anti-crack layer mixture optimum gradation range determined by the relevant technical indexes of the Marshall test,and ultimately determine the ore mixture ratio of 2.36 ~ 4.75:0 ~ 2.36: mineral powder =31.5:67.5: 1,and the best dosage of asphalt.Through the Marshall test showed that the optimum dosage of basalt fiber optimal asphalt aggregate ratio and asphalt mixture of asphalt mixture corresponding to the fiber content in about 0.4%,according to the optimal amount of rutting test fiber is 0.40%.Secondly,to evaluate the high temperature stability of waterproof and anti-crack layer through laboratory simulation of pavement performance rutting test,low temperature cracking test beam bend test evaluation of its ability to resist low temperature deformation,immersion Marshall test,freeze-thaw splitting test and seepage test to evaluate the water stability,finally the shear strength and bond strength to evaluate the degree of adhesion between the layers of the asphalt pavement.This graduation project will asphalt pavement structure in southern rainy regions as a whole system to carry out in-depth research,in the analysis process,in order to ensure that the final conclusion is persuasive and certain rigor,so with a lot of related theoretical knowledge and analytical techniques,such as physics finite element the knowledge of mechanics,material parameter model analysis,structure analysis,not only explore in depth analysis of pavement waterproof cracking,but also in-depth study of the relevant content of pavement under pressure,is expected to draw certain conclusions,to effectively guide the construction of concrete pavement.Finally,according to the shortcomings in the concrete implementation process,such as cost problem,pavement waterproof cracking effect and road quality,put forward the corresponding treatment measures,and thus effectively ensure that the project can be completed within a specified time high quality. |
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