The Study Of Aging Mechanism Of Resin Color Cement

With the improvement of living standards,the road requirements are not limited to safety and comfort.Pavement color is gradually proposed for the coordination of the surrounding environment,so color cement is produced.However,the aging of the colored cement causes molecular structure changes in the actual use of the road surface,which affects the mechanical properties.In this paper,an improved coupling aging test box is used to study the aging rules of color cement,and propose the aging mechanism of color cement.Based on four raw materials to prepare color cement,according to the orthogonal test results of the three major indicators as model sample data,an improved three-layer colore cement cement physical property BP(Back Propagation)neural network prediction model is established.When the recommended raw material ratio of the model is A: B: C: D = 42.5: 42: 0.9: 5,the physical properties of color cement are the best.The artificial aging method was used to prepare the aged color cement,and according to the national summer maximum temperature,ultraviolet radiation and air humidity distribution to determine the conditions for simulating coupled aging,temperature 65℃,mercury lamp intensity 300 Wh,air humidity 60%.Besides,viscosity,dynamic shear rheometer,infrared spectroscopy,nuclear magnetic resonance,and gel permeation chromatography are used to study the changes in the macro properties and microstructure of color cement.The results show that with the aging time increases,the dynamic viscosity of the color cement increases linearly,the absolute value of the viscosity temperature index gradually increases,and the temperature sensing performance becomes weak.Besides,as the aging degree deepens,both the complex shear modulus and the rutting factor increase,the phase angle decreases,and the high temperature performance increases.Under the load,the deformation recovery of the color cement gradually weakened with the increase of the aging time.Microstructural tests show that the carbonyl and sulfoxide functional groups in color cement change significantly before and after aging.As the aging time increases,the carbonyl index and sulfoxide index increase.After aging,the carbon atoms directly connected with aromatic carbon in color cement increased obviously.With the increase of aging time,the average molecular weight and weight average molecular weight of color cement are increasing,and the dispersion coefficient is also increasing.Combined with B-L method,the structural characteristics before and after aging are analyzed,which shows that with the increase of aging time,the aromaticity and total ring number of color cement are increasing.The relationship between macro properties and micro structure of color cement is established by grey correlation analysis and principal component regression analysis.The results show that the three indexes of aromaticity,cycloalkane ring number,aromatic carbon number and color cement have good correlation.The correlation is between 0.78-0.82,and the correlation between carbonyl index and sulfoxide index and softening point is the smallest,between 0.40～0.45.Four chemical structures(carbonyl index,sulfoxide index,aromaticity,cycloalkane number)are retained in the linear diagnosis of principal component regression analysis.The reduction regression equation showes that the contents of four chemical structures are negatively correlated with penetration and ductility,and positively correlated with softening point,and aromaticity was the main factor affecting the macro performance of color cement before and after aging.