Research On Performance Of Gussasphalt Based On Dry Modified Asphalt

Gussasphalt is widely used in the field of steel bridge deck pavement due to its excellent waterproof performance,durability and ability to follow deformation.When the pavement layer has network cracks,pits and other diseases during the operation period,it usually has a small area and does not have the production conditions during the construction period.Special asphalt binders are used for the production and construction of the mixture,while other types of mixtures cannot meet expectations Repair effect.The gussasphalt is high-temperature paving,dense and void-free,self-flow forming,no need for rolling,easy repair and construction,new and old joints are melted and bonded,and there is no risk of water leakage.However,the asphalt binder used in the gussasphalt is not ordinary modified asphalt,which needs to be prepared by wet modification,which is cumbersome and expensive.Therefore,this paper introduces dry modification technology to prepare asphalt binder for gussasphalt,which solves the material problem of repairing small batch gussasphalt in maintenance project.At the same time,the gussasphalt has the characteristics of long mixing time and high temperature,which is conducive to the dispersion and melting of the modifier in the dry modification mixing process.The two can achieve technical complementarity and complement each other.This paper draws on the existing bituminous binder production formula for gussasphalt,uses a melt-stirring modification process,and screens out suitable for dry modification through the performance index of modified asphalt and the dispersion state of modifier in asphalt polymer modifier.Based on this,the modified effects of the dry modifier compounded from the asphalt binder,asphalt mastic and mixture are comprehensively evaluated.First,based on the action mechanism of the modifier for gussasphalt,the matrix asphalt and polymer modifier are screened,and the polymer modifier A and the finished product direct modifier C are selected for the dry combination of asphalt binder.Mixing,and further screening through viscosity reducer and natural asphalt,put forward the dry method 1 #,dry method 2 # modified formula.For the two formulations,the asphalt modification was carried out by melt stirring and high-speed shear,and the results showed that the differences in various indicators of asphalt binder under different processes were not obvious.Secondly,by comparing the rheological properties of asphalt mastic produced by dry and wet processes,the modifier’s modification effect under the condition of high mineral powder content was evaluated.The results show that as the powder-tobinder ratio increases,the modification effect of the dry modifier is affected to a certain extent.Too much mineral powder is not conducive to the swelling and dispersion of the modifier.Then,for the three factors affecting the dry powder modification time,total mixing time,mixing temperature,orthogonal test was used to determine the production control conditions of dry modification,and the mixing of different modification processes comparative analysis of material properties.The test results show that the high and low temperature performance of the gussasphalt prepared under the dry modification process is close to that of the wet modification and meets the corresponding technical requirements.Finally,through the implementation of the solid bridge maintenance project,it was found that the dry-process modification process of producing gussasphalt on site is easy to operate and has strong applicability.After on-site sampling test and follow-up observation,all technical indicators of the mixture meet the requirements of the actual bridge and are in good condition.In this paper,in view of the material production problems faced in the implementation of steel bridge deck pouring asphalt pavement maintenance,a mixture production technology based on dry modification process is proposed,which is of great significance for improving the quality of steel bridge deck pavement maintenance and extending the service life.