Research On Asphalt Pavement Climate Zones And The Modified Asphalt Adaptability In Tibetan

Tibet Autonomous Region located in south of Qinghai-Tibet Plateau with anaverage elevation over4000meters. The weather conditions are very complex withintense solar radiation, long duration of sunshine, mean annual temperatures and bigtemperature gap between day and night, which have a significant effect on thestructure and material of pavement. Tibet is a large region across multiple latitude andelevation, so it is divided into many climate zones. It makes the asphalt pavement inTibet most different from what in the other districts. To accelerate Tibet’s economy,more highways are required and urgent. The usage property and service level ofasphalt pavement must be enhanced. According to the above, this study will establishthe climate zones of asphalt pavement on the base of different weather conditions inTibet and recommended the modified asphalt and its index system of each zones.This study analyzed some main facts that affect the usage properties of asphaltpavement in Tibet such as solar radiation, maximum and minimum temperatures andthe temperature gap, and found out the related zoning index such as the average solarradiation of the highest temperature month for ages, the average extreme maximumtemperature for ages, the average daily temperature range in7consecutive days forages. Divide Tibet into5zones numbered Ⅰ~Ⅴ, judging bya decade’smeteorological statistics from1991to2000observed by28weather stations in Tibetand then make a4indicators’ cluster analysis using statistical analysis software. Bebased on China Specification for Design of Highway Asphalt Pavement, preliminaryevaluate6kinds of modified asphalt by a simple asphalt trabecular bending creep testequipment developed from BBR experiment in SHRP specification. Analyses creepstiffness modulus, S for instead, and creep strain rate, m for instead, of6kinds ofmodified asphalt under different temperatures and find out the sensibility in lowtemperature. Then find out the sensibility in high temperature by test the rheologyshear property using DSR test equipment. At last, recommended the modified asphaltin different zones, figure out the index of different kinds of modified asphalt and offerreferences to asphalt pavement constructions in Tibet.