| Rubber-plastic modified asphalt has the advantages of good elastic recovery,fatigue resistance and noise reduction,but at the same time,the defects of rubber-plastic asphalt limit its application and promotion.On the one hand,the storage stability of rubber-plastic asphalt is poor,which is not conducive to the high temperature of rubber-plastic asphalt.Storage and long-distance transportation restrict the mass production of rubber-plastic asphalt.On the other hand,rubber-plastic modified asphalt mixtures have high mixing temperature due to the high asphalt viscosity,which generates a large amount of smoke during the construction process,which will pollute the environment and affect the construction quality.Therefore,physical engineering puts forward higher requirements for the storage stability of rubber-plastic asphalt and the workability of asphalt mixture construction.In this paper,from the perspective of improving the storage stability of rubber-plastic asphalt and the workability of its mixture construction,a warm-mix rubber-plastic asphalt with good storage stability and significantly lower mixing and compaction temperature is prepared,which is a warm-mix rubber-plastic composite modification.Asphalt application provides reference.The main research contents and conclusions are as follows:(1)Single factor study of the storage stability and high and low temperature performance of three modified asphalts,select the orthogonal test factor level of each modifier,and the basic formula determined by the design orthogonal test is: 16%devulcanized rubber powder,PE blended The dosage is 2%,and the linear SBSY792 dosage is 3%.Furthermore,the basic formula was further studied to improve the performance of solubilizers and stabilizers,and the results showed that: the furfural extraction oil significantly improved the storage stability and low temperature performance of the rubber-plastic composite modified asphalt;sulfur improved the storage stability of the rubber-plastic asphalt Finally,it was determined that the content of furfural extraction oil and sulfide were 4% and 0.3%,respectively.(2)Two viscosity-reducing type warm mixing agents(abbreviated as FTA and FTB)and one surface active type warm mixing agent(abbreviated as C)were selected to prepare rubber-plastic asphalt for the preparation of rubber-plastic modified asphalt.The influence of the mixture on the performance of rubber-plastic asphalt.The mixing temperature and compaction temperature of different warm-mix rubber-plastic asphalt are calculated by the fitted viscosity-temperature curve formula,and the temperature sensitivity of the warm-mix rubber-plastic asphalt is evaluated;conventional tests show that FTA and FTB make the softening point of rubber-plastic asphalt Increase,penetration,ductility and elastic recovery decrease,but C has no obvious change on its effect;the anti-aging test shows that the three warm mix agents have a certain degree of improvement in the anti-aging resistance of rubber and plastic asphalt;the temperature scanning test shows,The phase angle of FTA and FTB rubber-plastic asphalt increases with the increase of the mixing amount of the warming agent,C rubber-plastic asphalt is the largest at 0.5%;the rutting factor and complex shear modulus change with the content of FTA and FTB at the maximum at 3%,And the influence of C on it slightly increases,the final content of FTA and FTB is selected to be 3%,and the content of C is selected to be 0.5%.(3)Analyze the upper and lower sections of the sample by fluorescence microscopy and infrared spectroscopy.The results show that the rubber powder particles in the upper and lower sections of the sample are evenly distributed,with a small difference in the proportion of particles,and there is no position shift of the absorption peaks in the upper and lower sections of the infrared spectrum.And the peak area changes greatly,indicating that the warm mixing agent has no adverse effect on the storage stability of the rubber-plastic composite modified asphalt;at the same time,the infrared spectrum analysis shows that the modification effect of the rubber-plastic composite modified asphalt is mainly physical modification,and there is no obvious Chemical modification,warm mixing agent mainly manifests physical modification to rubber and plastic asphalt.(4)By forming Marshall specimens and SGC specimens at different temperatures,the cooling effects of three warm-mix rubber-plastic composite modified asphalt mixtures are studied.The test results show that FTA reduces the compaction temperature by about 23°C,and FTB reduces compaction.The temperature is about18℃,and C reduces the compaction temperature by about 28℃.Different compaction methods have different compaction performances of warm-mix rubber-plastic asphalt.Under SGC test conditions,the cooling effect of warm-mix rubber-plastic asphalt mixture is more obvious.(5)The road performance of three warm-mix rubber-plastic composite modified asphalt mixtures was studied under warm-mix conditions,and compared with the hot-mix rubber-plastic asphalt mixture.The results showed that the high-temperature performance of the warm-mix rubber-plastic asphalt mixture was better.Increase the dynamic stability of the three types of warm-mix rubber-plastic asphalt mixtures:FTB>C>FTA;the low-temperature anti-cracking performance of the warm-mix rubber-plastic asphalt mixtures decreases,and the degree of decrease is FTB>FTA>C;warm-mix rubber-plastic asphalt mixtures The water stability of the mixture has been improved,and the degree of increase is FTA>C>FTB.The warm mixing agent C is recommended in the final physical engineering. |
