Prediction And Evolvement Rules Of Transverse Cracking For Asphalt Pavement In High Altitude Cold Regions Based On The Regional Characteristics

Transverse crack is the mainly disease form in Qinghai-Tibet high altitude cold regions.The research regarding diseaseof asphalt pavements in Qinghai-Tibet high altitude cold regions mainly reference the research means in inland cities,which is lacking the adequate consideration about environment and material in research area.The related research are mainly focused on mechanism and treatment measures of cracksat present while there is less research on the development trend of fracture;there is also less research which is reported that optimizing the structure of characteristic asphalt pavement which is depended on regional characteristics and considers key diseases.In addition,road technical class is mainly second class or lower in high-elevation and frosty area and its construction technology can not satisfied the construction requirement of high-grade highway.To clear theregional characteristics of asphalt pavement in high-elevation and frosty area,and proposed a reasonable prediction method of transverse cracks of asphalt pavement in high-elevation and frosty area,and reveal the evolvement rules of transverse cracks of asphaltpavement in high-elevation and frosty area,this paper aimed at transverse crack of asphalt pavements in high-elevation and frosty area and was based on the projects that G214 Qing-Kang Highwayproject,G109 the Qinghai-Tibet Highwayproject,Gong-Yu expresswayproject and respectively carried out the analysis of regional characteristics,research on the combined prediction model of transverse crack,and study on the evolvement rules of transverse crack.The main research content are as follows:(1)Environment characteristic analysisThis paper aims to analyze the reginal characteristics of asphalt pavement in high altitude cold regions in terms of climate properties,pavement engineering characters,road disease characters and low temperature performance of pavement materialsbased on the China Meteorological Science Data Sharing Serviceand datum obtained in field investigation.The environmental characteristic model was established in this paper by investigating the climate factors in the study areas.The frozen earth condition and variations in earth temperature and disease distributing characteristic were also considered in this model.(2)Low temperature characteristics analysis of asphalt mixtureThe evaluation system of asphalt mixture low-temperature anti-cracking performance was proposed based on cold bending test,splitting test and aging test of both environmental characteristic model and real asphalt mixture.What is more,the experiments condition was modified in this evaluation system.The surface material parameter combination was also recommended in this paper,which can illustrate the low-temperature decay characteristics of asphalt mixture in high altitude cold regions.(3)Prediction of transverse crack of asphalt pavementBased on the results of regional characteristics classification,and basic of the progject of G214 and G109 line,the measured data of transverse cracks in 425 observation section wereobtained,and the observation database of transverse crackof asphalt pavement in high altitude cold regions was also built.The paper used the NCHRP1-37 Aprediction model as the main sub models and the DGM(1,1)grey dynamic model as the correction model,to establishe a combination prediction model consiedered regional characteristics(NHR-DGM combination model).Theresearch results could provide the reference for predictionthe other disease of asphalt pavementin high altitude cold regions.(4)Evolvement rules of transverse crack of asphalt pavementBased on the prediction results of the NHR-DGM combination model,and take the five typical structure in gongyu highwayas study objects,and combined with the matter-element analysis method to build the evolvement curve of transverse cracks for each pavement structure,and the low temperature performance of SBS modified asphalt pavementand warm mix asphalt rubber pavementin high altitude cold regions also be analyzed.Finally,thereasonable structureof asphalt pavement with good crack resistance in high altitude cold regions are recommended which considered the reginal character,and the established evolvementcurves of transverse crackcan help to ensure the optimal period of the matainace for pavement in high altitude cold regions.