Study On Rheological And Adhesion Properties Of LUCOBIT/Rubber Composite Modified Asphalt

This article uses LUCOBIT 1210 A additive produced by German Lucobit Company and waste tire rubber powder to compound modified asphalt,and conducts research on the rheology(such as high temperature rheological characteristics and low temperature rheological characteristics)and adhesion characteristics of rubber asphalt and composite modified asphalt The method of combining theoretical analysis and experimental research was used to discuss the high-temperature rheological characteristics of the composite modified asphalt rheology,and its low-temperature performance was tested by the bending beam rheometer(BBR)test.At the same time,the microscopic morphology of the composite modified asphalt was tested based on atomic force microscope(AFM),and the anti-aging properties of the composite modified asphalt were further analyzed.Finally,using basalt as aggregate,the bond properties of composite modified asphalt and basalt aggregate before and after water damage were studied through macro-adhesion tests(normal pull test and diagonal shear test).Provide an important technical guarantee for further improving the high temperature performance,anti-aging performance and adhesion characteristics of rubber modified asphalt.The main research results achieved in this paper are as follows:1.Based on LUCOBIT 1210 A additive and waste tire rubber powder produced by German Lucobis,select the amount of LUCOBIT 1210A(5% and 10%)and the amount of waste tire rubber powder(15%,20% and 25%)for rubber asphalt and compound Preparation of modified asphalt,and short-term aging and long-term aging by rotating film oven(RTFO)and pressure aging vessel(PAV).The dynamic and rheological shear meter(DSR)was used to scan the temperature and frequency of the rubber asphalt and composite modified asphalt before and after aging,and to analyze the change law of its complex modulus and phase angle,and further carried out multiple stress repeated recovery tests(MSCR)analyzes its stress sensitivity,and uses Burgers rheological constitutive model to fit repeated creep test data and analyzes various asphalt viscoelastic properties.Finally,the bending beam rheometer(BBR)was used to study the low-temperature rheological properties of various asphalts.The results show that the high temperature performance of composite modified asphalt is better than that of single rubber powder modified asphalt;rubber powder can increase the stress sensitivity of asphalt,but the addition of LUCOBIT 1210 A can effectively reduce the stress sensitivity of asphalt;viscoelastic characteristics analysis It shows that rubber powder and LUCOBIT 1210 A mainly improve the asphalt deformation recovery ability by increasing the proportion of asphalt's delayed elasticity.Rubber powder can effectively improve the low temperature performance of asphalt,but LUCOBIT has no obvious effect on improving the low temperature of asphalt.2.Atomic force microscope(AFM)was used to test the surface morphology of the various asphalt samples prepared,and the anti-aging properties of the composite modified asphalt were analyzed by observing the size and size of the honeycomb shape.And through infrared spectroscopy(FTIR)and thermogravimetric analysis(TG)of its functional group and molecular structure changes and thermal stability.The results show that both rubber powder and LUCOBIT have anti-aging effects,and the anti-aging effect of LUCOBIT is more obvious.Infrared spectroscopy analysis found that pure rubber powder modified asphalt has no new functional groups.Rubber modified asphalt belongs to physical miscibility and is a non-uniform system;rubber powder and LUCOBIT composite modified asphalt produce new functional groups with weak chemical reaction.Thermogravimetric analysis found that adding a certain amount of rubber powder and LUCOBIT did not affect the thermal stability of the asphalt,and a large mass loss occurred between 300? and 600?.3.In this paper,by using basalt as aggregate,the normal pull test and oblique shear test are used to analyze the bond performance of asphalt and aggregate under two failure modes,and the bond performance after accelerating water damage by controlling the environment(water temperature)Law of change.By analyzing the test results under two different failure modes,the study found that increasing the rubber powder content increases the tensile strength and diagonal shear strength,but when the rubber powder content exceeds 20%,the tensile strength and diagonal shear strength The increase decreases.LUCOBIT modifier can further improve the bond tensile strength and diagonal shear strength of asphalt and basalt;after accelerating water damage,it is found that the more rubber content,the greater the degree of damage,the addition of LUCOBIT modifier can reduce its water damage,while It is found that the normal pull bond strength is 10-20 times the oblique shear bond strength.