重交通沥青路面层间黏结状态对开裂的影响分析

Analysis on the Influence of Interlayer Bonding Conditions on Cracking of Heavy Duty Asphalt Pavement

开裂已成为重交通沥青路面的主要病害,钻芯取样发现上、中面层层间因黏结力丧失而存在脱离的现象,而良好的层间黏结状态是确保沥青路面充分发挥路用性能、保持长寿耐久的关键。层间黏结状态受黏层材料种类、温度、水和老化等影响,文中利用剪切试验与拉拔试验对5种黏层材料从温度变化、冻融循环、黏层油老化等方面进行了性能评价和排序。结果表明:层间抗剪强度和拉拔强度受温度影响很大,随着温度的升高急速降低;冻融循环可使抗剪和拉拔强度降低20%以上;黏层材料经长期老化之后,层间抗剪强度衰减约25%~35%,拉拔强度降低约15%~35%;所选材料中橡胶SBS复合改性沥青性能最为优越。

Cracking has been the major defect of asphalt pavement under heavy traffic,after taking core sample by drilling,it is found that the upper and medium surface layer are detached due to the loss of adhesive force,and fatigue cracking of the surface layer could easily occur.A good state of adhesion between layers is a prerequisite for asphalt pavements to give full play to road performance and maintain long serviceability and durability.The state of adhesion between layers is influenced by the material type,temperature,water and aging of the adhesive layer.In this paper,the shear test and pull-out test are carried out to evaluate and rank the properties of five types of adhesive materials from the aspects of temperature change,freeze-thaw cycles,and oil aging of the adhesive layer.The results show that:the shear strength between layers and the tensile strength is greatly influenced by temperature,and decreases rapidly with the increase of temperature;the freeze-thaw cycle can reduce the shearing and drawing strength by more than 20%;after a long-term aging of the adhesive layer material,the shear strength between layers decreases by some 25%to 35%,the drawing strength is reduced by about 15%to 35%;and the rubber SBS composite modified asphalt has the best performance in the selected material.