Study On Preparation And Performance Of Porous Epoxy Asphalt Mixture

The structure of the porous asphalt mixture is a typical skeleton-void type,and its internal strength is mainly derived from the stone-stone intrusion and the adhesion of the asphalt binder to the aggregate.Studies have shown that the porous asphalt pavement has the problems of poor durability,limited fatigue resistance and aging resistance in some heavy traffic sections.The use of epoxy asphalt as binder for porous asphalt pavement will help to improve the strength and durability of porous asphalt pavement.However,most of the epoxy asphalt commonly used in the market is hot-mixed and warm-mixed epoxy asphalt.The contradiction between the retention time and curing time increases the risk of epoxy asphalt quality.In this paper,a cold-mixed epoxy asphalt material with good performance and fast post-curing was prepared by means of curing agent compounding,condition optimization screening.The cold mixed epoxy asphalt is used as binder of porous asphalt mixture,and the performance of porous epoxy asphalt mixture is studied.The main conclusions of this paper are as follows:(1)According to the compatibility,tensile properties,rheological properties and other conditions of epoxy asphalt,the best proportion of the main materials of cold-mixed epoxy asphalt was selected.When the amount of epoxy resin is 100 parts,the basis asphalt is 90 parts,the curing agent is compounded with 90 parts of curing agent?₃ polyamide and 4 parts of curing agent?₂ polyetheramine,the tensile properties of the cold mixed epoxy asphalt prepared,Rheological properties,viscosity properties,resistance to water infiltration are good.In terms of tensile properties,the tensile strength of epoxy asphalt is 2.9MPa,and the elongation at break is 132.1%;in terms of rheological properties,it takes about 50min when the epoxy asphalt reaches 3000 m Pa·s;in terms of bonding strength,Epoxy asphalt has good bonding properties with cement concrete slabs,the pull-out strength of epoxy asphalt and cement concrete slabs is as high as about 1.7MPa;in terms of water resistance,epoxy asphalt and The contact angle of water is greater than90°,which has good resistance to water infiltration.(2)Based on the design ideas of graded blending and coarse aggregate void filling(CAVF)method,the gradation of the porous epoxy asphalt mixture is designed,and the aggregate is divided into two grades of coarse and fine aggregate.Coarse aggregate gradation is dominated by frame extrusion,which is determined by graded blending,fine aggregate gradation is mainly dense,which is determined by Fuller's maximum compaction curve theory,and coarse and fine aggregate gradation is combined by coarse aggregate void filling method(CAVF)is determined to ensure that the gradation stability and void ratio of the mixture can reach the design requirements.(3)Study on the molding time of the porous epoxy asphalt mixture.From the perspective of void ratio and cleavage strength,the insulation time of the porous epoxy asphalt mixture should not exceed 20min after mixing,and it should be compacted immediately after mixing.At the same time,the comprehensive voidage,splitting strength,pendulum value and other indicators of the porous epoxy asphalt mixture are combined to determine the optimal epoxy asphalt oil stone ratio,thereby correcting the mixture gradation.The test results show that the porous epoxy asphalt mixture has better porosity,mechanical strength and anti-sliding ability under the modified mix ratio.(4)The road performance and functional performance of the porous epoxy asphalt mixture are studied,and it is found that the mixture has good high temperature stability and water stability,but its low temperature performance needs to be improved,and may be mixed with asphalt thinner and high The amount of epoxy resin is related.At the same time,the porous performance and anti-slip performance of the porous epoxy asphalt mixture are also excellent.The anti-slip performance of the mixture is almost not affected by the epoxy asphalt solid phase film.