| RET is a new type polymer asphalt modifier, it is a chemical elastomerpolymerized by ethylene main chain and two copolymer monomers, and its chemicalgroup can be reacted with asphalt to form a stable compound, making it very difficult toseparated from asphalt, the characteristic is also very good, it has excellent compatibility,and there are no by-products and volatile matter be formed. This paper made a a morein-depth research and analysis of its mechanism through observing a large number ofexperiments on the performance of the RET modified bitumen as well as asphaltmixture.On the basis of understanding the research status and development trend ofpolymer modified asphalt at home and abroad, considering the various evaluation andexperimental methods, this paper combines the routine testing and rheological testmethod to make a contrast test research on technical performance for different dosageRET modified asphalt and SBS modified asphalt with the same base asphalts. Throughneedle penetration, softening point test, original asphalt and aging residual asphalt DSRexperiment, ductility test, BBR experiment, force-ductility tests to measure the qualityof RET modified asphalt in the aspects of temperature susceptibility, high-temperaturebehavior and cryogenic property; also, comparing the quality, ductility as well aspenetration of asphalt RTFOT before and after to study the aging properties; throughRTFOT and PAV residual asphalt’s DSR experiment to study the fatigue performance;through the storage stability test and elastic recovery test to study their compatibilitystability and elastic recovery properties. For different types of asphalt, The sameaggregate and granular composition are used to study the high temperature stability, lowtemperature crack resistance and water stability of RET modified asphalt mixture withthe rutting test, bending test, adhesion test, immersion Marshall test and the freeze-thawsplitting test. Analysz the effect of RET dosage on the performance of asphalt and itsmixture.The research indicate that the mixed RET modifier can significantly improvethe temperature sensitivity, high temperature stability, fatigue resistance and anti-agingproperties of asphalt, but the improvement of the low temperature performance forasphalt is not so obvious, in addition, RET modified asphalt also has excellent elasticrecovery property and storage stability, can be long reset or be transported for a longtime. RET modified asphalt mixture has very good ability of resistance to rutting deformation and water damage, the low temperature crack resistance is also improved,especially suitable for high temperature and rainy regions and long life pavement. Therecommended best dosage is1.5%of asphalt’s weight, which is the same as4%dosageof SBS modified asphalt fairly.Through the analysis of the RET chemical structure, at the same time using theelectron microscope and infrared spectrum experiment to analyze the existing form andmechanism of RET modified asphalt, The procedure and mechanism of the reaction ofRET with asphalt is researched from microscopic view, the result shoows that RET andasphalt undergoes a chemical reaction to form a uniform distribution chain structure. Atlast, the economic and social benefits of RET modified asphalt has been analyzed, RETmodified asphalt is very easy to maching, has a low required dosaget, cost-effective, andhas broad application prospects. |
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