Study On Resistance Of Ultra-high Performance Casting Asphalt Mixture To Reflection Cracking

Reflection cracking of semi-rigid or rigid base asphalt pavement is always a difficult problem in the field of road engineering technology.For repairing old road surfaces,a common method is to lay asphalt mixtures on the old surface.However,due to the presence of joints or cracks on the old surface,the asphalt layer will gradually reflect and crack under the effects of temperature and vehicle load,and even reflective cracks may appear.The presence of these cracks reduces driving comfort and safety,increases maintenance frequency,and shortens the service life of the road.In order to fully utilize the material and structure of the original road surface,reduce or delay the phenomenon of reflection cracking,and reduce the frequency of major and medium repairs,this paper proposes Ultra-high Performance Casting Asphalt(UHCA)rapid crack treatment technology.This technology uses UHCA with excellent tensile deformation ability,resistance to rutting,and waterproof performance.By adding a small amount of UHCA filling material to the position of reflection cracking,the thickness of the penetrating layer can be increased,and the strong stress dissipation and absorption anti-cracking effect helps to absorb the stress of the structural layer,thereby delay the time of road surface reflection cracking,improve the durability of surface layer and prolong the service life of pavement.To verify the performance of UHCA in resisting reflection cracking,this paper systematically studied the long-term performance and effects of UHCA in treating cracks,the mechanism and evolution law of reflective cracks,and the prediction of the reflection cracking time of UHCA through theoretical analysis and indoor test methods,based on existing research.The ability of asphalt mixtures to resist reflection cracking under temperature factors was evaluated using the Overlay Test(OT)test method developed by the Texas Transportation Institute.This paper used existing and self-made fixtures to conduct OT tests on a UTM testing machine,and studied the performance of UHCA in resisting tensile fatigue under different temperatures,maximum opening displacements,and different asphalt mixtures.In order to compare the performance with common asphalt mixture,GAC-13 asphalt mixture is selected as the comparison object.The results show that UHCA has good anti-cracking performance.The small-scale road accelerated loading test is a scientific and reasonable method for evaluating the anti-reflection cracking performance of asphalt mixtures using an indoor traffictype reflective crack test method.Compared with traditional indoor specimen fatigue tests,studying the fatigue resistance of asphalt mixtures by using small-scale road accelerated loading tests is a scientific and reasonable method.In this study,small-scale road accelerated loading test was used to test the uniaxial compression resilience modulus of specimens under different loading times,so as to determine the attenuation law of asphalt mixture modulus and reveal its fatigue damage law.The results show that the fatigue failure resistance of UHCA under traffic load is higher than that of the GAC-13 and SMA asphalt mixture under the same test conditions,and it has a better resistance to fatigue failure.