Research On Preparation And Performance Of A Storable Cold Patch Asphalt Mixture

Asphalt pavement will produce potholes and other diseases in the long-term use of the process,seriously affecting traffic safety and road life.At present,the road maintenance department mainly uses the hot mix asphalt mixture to repair the potholes,but it is greatly affected by the environmental temperature and construction conditions,which makes it difficult to deal with the potholes in time and affects the comfort of road driving.Cold patch asphalt mixture is gradually favored by the maintenance department because of the convenience of construction,little environmental pollution,and not limited by the use of time and environmental characteristics.However,the quality of products at home and abroad varies,making it difficult to use on a large scale,so the study of cold patch asphalt mixture and its road performance is of great significance.In this paper,firstly,diesel fuel was selected as diluent,wetting agent(diethylene glycol),plasticizer(oleic acid)and surfactant(diethanolamine of coconut fatty acid)as additive raw materials,and a four-factor,four-level orthogonal test scheme was selected according to the material type and dosage,and then the material samples were obtained by using the preparation method of cold patch asphalt liquid.Three schemes of cold patch asphalt liquid were selected through Brookfield rotational viscosity test,volatility test and low temperature bending beam rheology test,etc.The test results show that the three solutions have certain volatility and excellent low temperature performance,and have good adhesion with the aggregate.The microscopic property changes of the cold patch asphalt liquid were investigated by infrared spectroscopy,atomic force microscopy and gel permeation chromatography tests.The test results show that the preparation of cold patch asphalt liquid is a complex physical reaction process,and its micro performance test results can correspond to the macro performance test results.Secondly,through the analysis of the maximum particle size and gradation type,it was determined to use LB-13 grade to prepare cold patch asphalt mixture after the verification of the Bailey method.Based on the initial determination of the optimum asphalt dosage by the empirical formula method,combining with the specification recommendations,the five dosages of cold patch asphalt liquid in the Marshall test were proposed,and then the optimum asphalt liquid dosage for the three cold patch asphalt liquid was calculated by the maximum gross bulk density,maximum stability and median void ratio.Finally,according to the construction workability test,cohesion test,modified Marshall stability test and other performance evaluation methods to study the road performance of cold patch asphalt mixture,the test results show that the construction workability of cold patch asphalt liquid and cohesion of the three schemes meet the-requirements,but the strength,water stability,high temperature stability and low temperature crack resistance of scheme 4(diluent:wetting agent:plasticizer:surfactant ratio of 20:0.6:6:6,respectively).The strength,water stability,high temperature stability and low temperature crack resistance of scheme 4 are better,and it shows excellent road performance.The construction workability,strength and other performance of scheme 4 before and after storage can be concluded that scheme 4 has better storage stability,so it can be used as the optimal scheme for cold patch asphalt liquid.