Research On Emission Characteristic And The Emission Inhibition Method Of The Volatile Organic Compounds Of Rubber Asphalt

As the increase of vehicles amount,waste tires increases by around 12% each year.It has reached 5 million tons each year.To a certain extent,rubber asphalt prepared by certain processing technology can improve the high and low temperature performance,fatigue resistance and noise reduction of the asphalt pavement,which widens the use area of bitumen.However,there are few literatures on the compounds and the potential hazards to construction workers and the environment of volatile organic compounds(VOCs)released from crumb rubber modified bitumen(CRM)during the preparation,storage and paving.Previous studies mainly focused on chemical components and total concentration of organic compounds of VOCs collected in the field.In this study,the gas chromatography-mass spectrometry(GC-MS)was used to analyze the release characteristics of VOCs of the base bitumen and CRM.Meanwhile,the inhibition effect on VOCs of CRM by using organic-montmorillonite was evaluated.Firstly,this study optimized the collection device and test parameters,combined with the characteristics of collection device.It built the foundation for the further research of the release characteristics of VOCs from bitumen.Secondly,the main components of VOCs from two base bitumens and two CRMs were analyzed.The emission of VOCs of bituminous binders was mainly correlated with the temperature.Therefore,160°C,180°C and 210°C were chosen in the test.The results indicated that the main components of VOCs from base bitumen mainly contained saturated hydrocarbons and a small amount of benzene series.The alkanes were mainly composed of long straight chain or branched alkanes.Benzene series were mainly composed of benzene and its derivatives,and contains a small amount of naphthalene and derivative of benzo[b]thiophene.The VOCs from CRM mainly contained alkanes and benzene series,but it also contained a small amount of alkene,alcohol and aldehyde.Compared with VOCs from base bitumen,the type and structure of VOCs from CRM were more complicated.The main reason for this was that a lot of benzene series were released from crumb rubber during the swelling process.The compounds of VOCs from bitumen were associated with the property of bitumen and crumb rubber.Finally,based on determing the release amount and the typical compounds of VOCs from CRM,this study evaluated the effect of organo-montmorillonites with different surfactants on the inhibition to the VOCs emission and explored the mechanism of inhibition of organic montmorillonite on the emission of VOCs.The results indicated that organo-montmorillonites can effectively inhibit the VOCs emission of CRM.Compared with the VOCs from CRM+ Mt1,VOCs from CRM+ Mt2 contained some new compounds,which was closely linked with benzyl dimethyl hexadecyl ammonium salt.The inhibition effect of Mt1 was better than that of Mt2 for VOCs from CRM.