| At present,the construction temperature and pollution of hot mixed color asphalt mixture are high at home and abroad.Meanwhile,there are also some problems in the cold-mix colored asphalt mixture during its service period,such as insufficient pavement performance and colored durability.In this paper,a reactive ambient temperature colored asphalt was prepared using decolorized asphalt as original material,inorganic pigments as colorants(red,yellow and green),unsaturated fatty acids as diluents,SEBS and epoxy resin as modifiers,YS-180 and triethylenetetramine as curing agents in the laboratory.The fundamental performances of the ambient temperature colored asphalt were studied.The ambient temperature colored asphalt mixture mix method was designed,and the pavement performance and color durability were analyzed.The main research results include:(1)Three kinds of inorganic pigments(red,yellow,and green)were selected by comparing.The coloring power,oil absorption and light resistance of colored asphalt were verified.The results showed that the pigment performance met the technical requirements of"Technical specification for colored asphalt concrete pavement of urban road"(2)Through the single factor experiment and the orthogonal test that took viscosity as the control index.The optimal formula of colored asphalt at ambient temperature was obtained(decolorized asphalt:unsaturated fatty acid:SEBS:epoxy resin=100:25:3:12).According to the test results of three indexes of asphalt,the best dosage of the YS-180 curing agent is 7%.Under the optimal formulation conditions,the ambient temperature colored asphalt 60℃ Brinell viscosity was 2.38Pa·s,25℃ penetration was 69mm,softening point reached 73℃,5℃ ductility was 48cm,and the adhesion grade was 5.DSR and BBR test results indicated that:the modified ambient temperature colored asphalt showed good high-and low-temperature performance,in which the high-temperature performance was improved significantly.And the PG grade of asphalt was 70-22.The IR,SEM,and fluorescence microscopy results indicated that the decolorized asphalt was in a stable physical blending state with good compatibility.(3)The best CAC-13 dense grade was selected as the design gradation of ambient temperature colored asphalt mixture.Three types of gradations were designed for compasion while the sieve of 2.36mm was a key control indicator.According to the Marshall stability test results,the best gradation was the fine CAC-13F.The optimum asphalt aggregate ratio was determined as 6.4%by Marshall’s physical and mechanical index.(4)The performance of CAC-13F colored asphalt mixture pavement at ambient temperature was obviously improved.The forming stability was 9.74kN,and the dynamic stability was 4556 times/mm,which has exceeded the index requirements of special color asphalt concrete for a motorway in "Technical specification for color asphalt concrete pavement of urban road".The maximum bending strain was 2709.4με,which was higher than the standard of low-temperature performance of urban motor vehicle lanes.The Marshall test results and freeze-thaw splitting test results were 84.02%and 77.8%,respectively,which met the requirements of moisture stability of motor vehicle lane.The structure depth was 0.98mm,and the pendulum value was over 45BPN,which showed that it had an excellent anti-sliding performance.(5)Based on the chromatics evaluation index and polar space coordinate system,the optimal amount of each type of pigment was determined,and the color durability test evaluation system from asphalt to the mixture was established.Several tests verified the comprehensive color durability of CAC-13F colored asphalt mixtures,such as RTFOT,PAV,UV irradiation,wheel rolling,oven heating and vacuum water saturation test.The test results demonstrated that the colored asphalt mixture has good color durability which can be applied to areas with high ultraviolet radiation intensity and humid,hot and rainy. |
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