Study On Multi Index Of Asphalt Pavement Preventive Maintenance Scientific Decision-making

By the end of 2014,in our country,highway mileage has reached 4.4639 million kilometers including111936 kilometers expressway,ranking ahead in the word.As the highway opened,different degrees of damages and diseasesgradually appeared on roads.If these damages and diseases couldn't bemaintainedpromptly and properly,they will lead the performance of pavementdecreasing quickly,which finally will resultinto medium-capital overhauling and funds wasting.The Twelfth Five-year Plan issued by Ministry of transportation includes the regulations that length of annually maintained segments should not be less than 17% of total mileage of highway,which should not be less than 758900 kilometers.In our country,medium-capital overhauling is widely used;however,preventive maintenance applied less.Preventive maintenance measure,which differs from common maintenance measures,is an early pavement maintenance at the beginning of pavement damage.It could effectively lengthen the life of pavement,slows down pavement damage,which will result in maintenance costs decreasing.For the preventive maintenance problems mentioned above,our researches include the following aspects:(1)This paper contains the specific introductions of common method for asphalt pavement preventive maintenance,which include material,cost,construction methods and service life.For curing method according to the thickness and strength capability maintenance disposal of disease degree level,also analyzed the effectiveness of application of common preventive maintenance measures.(2)For preventive maintenance segment,early damages and their causes were analyzed,especially crack disease,water damage,rutting and badly skid resistance and so on,and established special investigation methods of preventive maintenance aiming at preventing some early forepart dangers in the asphalt pavement.(3)An index system of preventive maintenance was established according tothe characteristics of preventive maintenance.On the basis of the preventive maintenance system,optimization of the gray clustering evaluation method was proposed.The optimization of the gray clustering evaluation method was applied to the decision-making evaluation of preventive maintenance segment,in order to determine the level of preventive maintenance.(4)Making final decisions according to the road which is based on the level of maintenance degree by the policy-making tree of preventive maintenance and grey fuzzy synthetic evaluation method.The preventive maintenance decision method aiming at disease is through the establishment of preventive maintenance policy-making tree.Grey fuzzy synthetic evaluation method is in maintenance scheme on the basis of cost and pavement performance indicators.Two different maintenance selections are given separately from the perspective of disease and the perspective of preventive maintenance plan.