Research On Asphalt Pavement Crack Sealing Technology

Cracks are the most frequent and common forms of damage on asphalt pavement.Grooving and grouting is a common way to seal cracks in asphalt pavements.However,there is a problem with the long-term performance in this kind of crack sealing technology,and it is difficult for sealants to maintain a tight bond with the pavement for a long time.The sealants are tend to fail after 1 to 2 years which affects the pavement service function and increases the maintenance costs.Therefore,solving the problem of the short-term validity of asphalt pavement cracks sealing is necessary to improve the long-term performance of sealants and reduce the asphalt pavement repairing cost.The main work of this paper is as followed:First of all,this paper establishes an asphalt pavement model which has a crack repair structure on the top in Abaqus,in order to analyze the temperature stress distribution characteristics of the bonding interface of the repaired structure under different climate zones.The temperature calculation results are used as predefined fileds in temperature stress simulation model.The mechanical response characteristics of the repaired structure under different bonding states are analyzed.In order to avoid temperature cracks in the repaired structure,the performance requirements of bonding interface under different climate zones are proposed.Secondly,this paper established a three-dimensional pavement model with a repair structure on the top.he moving non-uniform load are controlled by the subroutines.Comparison of the mechanical response characteristics on the bonding interface between the model with different size of grooves are made.The optimal size of groves is recommended.It is recommended to set the repair groove size to 15～30mm in depth and 12～18mm in width.The paper analyses the impact of different axle loads and moving speeds on the mechanical response characteristics on the bonding interface.The results show that the frequent action of low-speed and heavy-duty vehicles is more likely to cause damage to the repaired structure.The bonding interface is more likely to produce tensile failure under the action of climatic factors according to the simulation results of the coupling effect of the root temperature field and the load field.Finally,this paper studies the long-term bonding properties of sealing materials and proposes an evaluation method for the long-term bonding properties.The effects of test parameters such as the bonding substrate and the tensile rate on the test results are compared.In this paper,three types of sealing materials are used for testing.The test results show that the ductility of the sealants decreases after the cold and heat cycle treatment.The applicable area of the repair material can be judged according to the maximum stress during the stretching process under low temperature.The change range of the stretching-separation stiffness can help to ranking different types of sealent according to the bonding performance.