| Epoxy asphalt has completely changed the properties of asphalt that is easily softened at high temperature and hard and brittle at low temperature.The obtained epoxy asphalt material has excellent performance and is widely used as a bridge material for large-span bridges.However,there are various problems in engineering practice(1)Material properties.High brittleness,poor toughness,and poor dispersion uniformity between epoxy resin and asphalt due to density and polarity differences.(2)Construction.In order to ensure the leveling of epoxy asphalt mixture and sufficient workable time,the paving viscosity needs to be controlled within 1000 m Pa·s,and the time for the viscosity to increase to this value at the beginning of the mixture requires more than 60 minutes.The mixing temperature of high temperature mixing epoxy asphalt is above 160 ~oC and even as high as 180 ~oC.Temperature is the promoting factor of epoxy resin reaction.The viscosity of epoxy asphalt increases rapidly at high temperature,and the construction operation time is too short to be applied in engineering.In this paper,several curing agents are used to solve the above two problems encountered in leopard mixed epoxy asphalt.The main research contents are as follows:(1)The main components of the industrially produced high-temperature mixing type epoxy asphalt epoxy resin(Epoxy system of a brand)are analyzed.(2)A variety of fatty amines(dodecylamine,tetradecylamine,hexadecylamine,octadecylamine,oleylamine)are used as tougheners to prepare epoxy asphalt,and the carbon chain length of fatty amines on the toughness and The effect of uniform dispersion.(3)Polyetheramine as a high-temperature curing agent and fatty amine as a toughening agent.When mixing at180 ~oC,determine the best ratio of epoxy resin,polyetheramine and fatty amine;analyze the curing process and explore the high-temperature reaction time(1 hour,2hours,3 hours)on the performance of epoxy asphalt materials.The experimental results are as follows:(1)The main agent of brand of Epoxy system on sale is bisphenol A epoxy resin,the epoxy value is 0.45～0.54.In addition,the main agent also contains monoepoxy group substances;the curing agent mainly contains aliphatic primary amines,of which the largest proportion is octadecane Alkenylamine(oleylamine)may also contain polyamides.(2)The longer the molecular chain of the primary fatty amine added,the toughness of the epoxy resin increases,and the degree of uniform dispersion added to the asphalt increases.When the carbon chain length of the fatty amine is the same,the presence of double bonds in the main chain further improves the toughness and uniform dispersion of the epoxy resin.(3)The optimal ratio of epoxy resin,polyetheramine and fatty amine is 56:6.6:33,and the viscosity reaches 1000 m Pa·s after mixing with asphalt 1:1 for more than180 minutes,which meets the requirements of engineering practice.When placed at180 ~oC for two hours and then moved to 60 ~oC for 4 days,the final product has elongation at break and tensile strength of 298%and 2.62 MPa,respectively.With the extension of the reaction time at high temperature,the degree of precipitation and separation of epoxy resin in asphalt 1.The particle size of asphalt increases,and the mechanical uniformity of the material is good within the specified pavement thickness.The glass transition temperature of epoxy asphalt decreases,and the heat resistance does not change much. |
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