| Crack is a common disease form of asphalt pavement.Surface water is more likely to invade the interior of pavement structure along the crack.Under the combined action of vehicle load and temperature,it further induces diseases such as looseness and potholes,accelerates the damage of pavement structure and shortens the service life.Therefore,the appearance of cracks is one of the manifestations of asphalt pavement damage,and timely and effective treatment of pavement cracks can improve the integrity of pavement structure,reduce secondary diseases and prolong the service life of pavement.At present,the commonly used techniques such as crack filling and sealing have their own advantages,but there are limitations in the treatment of mesh cracks in asphalt pavement.Based on the above content,this thesis develops a kind of asphalt pavement water sealing anti-skid mesh crack repair patch for rapid treatment of mesh cracks.The repair patch structure is designed according to the functional requirements,and the materials used in each component structure of the repair patch are optimized with the performance as the index.The main research contents and conclusions of this thesis are as follows:(1)After investigating the diseases of S101 Hai Er Road and Tang Guo Road in Chongqing,it is found that the main types of diseases are loose,pothole and subsidence diseases caused by water intrusion into the structure along the pavement cracks.The proportion of reticular cracks in cracks is the largest.At present,the commonly used crack treatment technology performs well in the treatment of single cracks,but there are problems such as long construction time and high cost in the treatment of mesh cracks.In order to improve the maintenance efficiency,this thesis puts forward a kind of asphalt pavement sealing water anti-skid mesh crack repair patch structure.Based on the experience of repair engineering and the actual needs,the design principle of repair patch is put forward.The repair patch is set to three layers,and the first layer is the interlayer bonding layer,so that the repair patch has good bonding performance with the original pavement.The second layer is the tire base,so that the repair patch itself has good crack resistance and can play a water sealing effect when treating mesh cracks;the third layer is the anti-skid layer to restore the anti-skid performance of the original pavement.(2)Therefore,it is necessary to test the tensile strength,elongation at break and cumulative micro-strain of the primary material of the tire base with the change of loading times through tensile performance test and rolling fatigue loading test.It is found that woven composite geotextiles have the highest tensile strength and higher elongation at break among the three types of materials.At the same time,the cumulative micro-strain stability of woven fabrics after rolling fatigue loading is the lowest.Therefore,woven composite geotextiles are recommended as the base material for repairing tires.(3)In order to ensure that the mesh crack repair patch can normally play the function of water sealing and impermeability,the repair patch should be firmly bonded to the original pavement and not easy to peel off.Therefore,based on the shear test,the influence of temperature and loading rate on shear strength was studied.The test was carried out under different kinds of bonding materials,spreading amount and temperature conditions.The results showed that temperature and loading rate were important factors affecting the shear strength between the repair layers.The effect of temperature on shear strength is more significant than that of loading rate.The shear strength model based on exponential function considering temperature and loading rate has higher fitting accuracy.The shear strength of SBS modified asphalt with 0.9 kg/m~2is the highest at different temperatures,and it is preferably used as the bonding layer material for mesh repair.(4)The use of mesh crack repair patch can-not reduce the skid resistance of the original pavement.Through reasonable design,the repair patch can restore the skid resistance level of the mesh crack treatment position.Therefore,based on the accelerated loading test,the pendulum value and the structural depth are taken as the test indexes.Firstly,the anti-skid particle bonding material of the anti-skid layer and the application amount are optimized.The anti-skid performance decay law of the anti-skid layer of the same material with different particle sizes and the same particle size with different materials is studied,and the anti-skid decay model is constructed.The results show that based on the decay data of the pendulum value with the number of loading times under different bonding materials and dosage,SBS modified asphalt is selected as the anti-sliding particle bonding material,and the dosage is 1.5 kg/m~2.Based on the Asymptotic function,the anti-slip decay model of the anti-slip layer of the same material with different particle sizes and the same particle size with different materials was established,and the model fitting effect was good.Based on the characterization significance of the regression coefficient of the model,considering the initial value,final value,attenuation amplitude and attenuation rate of the anti-skid index,the comprehensive evaluation of the anti-skid performance and anti-skid durability is carried out.Finally,basalt is recommended as the anti-skid layer material for water sealing anti-skid mesh crack repair,and the particle size is 3～4mm.(5)The optimized materials were prepared into water-sealed anti-skid mesh crack repair patch,and the impermeability of the repair patch was verified by the test method of water permeability coefficient of asphalt pavement.The results showed that the repair patch was basically impervious and had good impermeability. |
