Preparation And Road Performance Evaluation Of Ion-chelated Odor-free Asphalt

In recent years,the problem of environmental pollution caused by waste rubber and waste plastics has become increasingly serious and has attracted widespread attention,and effective recycling of waste plastics and waste rubber has become an urgent task.Results showed that the use of waste rubber to modify asphalt alone or in a "collaborative" way with waste plastic for compound modification,the prepared rubber-modified asphalt and rubber-plastic composite modified asphalt have excellent pavement performance,and for asphalt pavement construction has some practical significance.However,rubber-modified asphalt and rubber-plastic composite modified asphalt will produce odorous flue gas in the production and construction process,which will pollute the environment and endanger health,and seriously restrict their popularization and application.Therefore,in this thesis,rubber-plastic composite modified asphalt was used to as an example,and analyze the components of its asphalt flus gas,then determine the smelly components.Two ion chelated deodorants and a plant alcohol deodorant were used to prepare deodorant asphalt,then study the physical properties and select the type and amounts of deodorants.In addition,the high-and low-temperature properties,rheological properties and the pavement performance of the mixture were studied,and the effect of the deodorant on the rubber-plastic composite modified asphalt was analyzed accordingly.Firstly,preparation of deodorant asphalt with three different deodorants(ion chelated deodorant A,ion chelated deodorant B and plant alcohol deodorant C),and compared the physical properties of asphalt and the odor classification of asphalt flus gas.Based on the results,the type of deodorant was selected.Results showed that the clean flavor asphalt with good physical properties,and deodorant A has the best effect.Secondly,the flu gas collection device was designed,and the main components of the rub ber-plastic composite modified asphalt flu gas was analyzed with the GC-MS test.Based on th e physical and chemical properties of flu gas components,the major pollutants in rubber-plasti c composite modified asphalt flu gas were determined,such as smelly components,then the eff ect of deodorant A was evaluated.In addition,combined with microscopic experiments,the de odorization mechanism of deodorant asphalt was explored.Results showed that the smelly com ponents of the rubber-plastic composite modified asphalt are sulfur-containing compounds such as benzothiazole,2-methylmercaptobenzothiazole,1-methyldibenzothiophene,thioxanthene and 2,7-dimethyldibenzothiophene,and there are butylated hydroxytoluene,1-methylnaphthale ne,toluene diisocyanate,hexachlorobenzene and other toxic components;the deodorant A can significantly inhibit the volatilization of asphalt flu gas,and reduce the concentration of smelly components in asphalt flu gas,and the recommended optimal dosage is 0.25‰?0.35‰;the ru bber-plastic particles presents a state of mutual accumulation after adding the deodorant A,the reby improve the stability of rubber-plastic modifiers in asphalt;in addition,the deodorant A c an have strong complexation with nitrogen,sulfur and other heteroatoms in the structure of het eroatomic substances in asphalt,forming stable macromolecular complexes after chelation reac tion,which can effectively inhibit the volatilization of sulfur elements in rubber-plastic compo site modified asphalt,and reduce the concentration of sulfur-containing organic substances in a sphalt flue gas,thus achieve the effect of deodorization.Thirdly,temperature sweep test,frequency sweep test,multi-stress creep stiffness test and asphalt bending creep stiffness test were used to explore the influence of deodorant A on the rheological properties of asphalt.Results showed that deodorant A can improve the high temperature performance of asphalt,the low temperature crack resistance of asphalt did not have a negative impact.Finally,the SMA-13 asphalt mixture was selected to prepare deodorant asphalt mixture,and rutting tests,freeze-thaw splitting tests and low-temperature beam bending tests were used to investigate the effect of deodorant A on the road performance of asphalt mixtures.Results showed that compared with the rubber-plastic modified asphalt,the clean flavor asphalt still has comparable road performance,and the addition of the deodorant A does not adversely affect the pavement performance of the asphalt mixture.