| Highway was developing rapidly,at the same time,many fatigue damage appeared and the cracks propagation are so quick that the control to the damage became useless.Especially,in the attenuation or loss of function of the asphalt pavement.In order to restore road function,further development of disease prevention and control,the preventive maintenance was urgently needed."High viscosity emulsion asphalt sand seal" is a new technology of asphalt pavement preventive maintenance,which has performance and efficiency advantages that other preventive maintenance technology have not.So it is gradually being popularized on the road.But the structural behavior of high viscosity emulsion asphalt sand seal mechanism also lack deeply understanding,also respective evaluation system has not been established and the material component design method has not yet formed.On the above,the system to carry out sand emulsified asphalt sand seal structural behavior and material component design research,focusing on exploring the impermeability,anti-slide performance,shear behavior of emulsified asphalt sand seal,so that it provides a theoretical basis to structure and material design of the emulsified asphalt sand seal.Specific studies include the following aspects.1.The main technical indicators of 6 kinds of emulsified asphalt and machine-made sand were tested.2.The spraying amount of emulsified asphalt and machine-made sand was determined by theoretical methods and off stone rate experiment.Firstly,the single particle size range of the sand is 3mm?5mm,which is determined by the comparison test of graded sand.Secondly,the theory spraying of emulsified asphalt and sand was determined by Mcleod theory method.Finally,the off stone rate test was constructed,and then the optimal spraying dosage of sand seal of the different viscosities and different solid content was determined.The kinds of emulsified asphalt for experiment road was also decided.3 The performance of anti-slide and impermeability of emulsified asphalt was obtained,which changed with emulsified asphalt spraying dosage,viscosity,solid content.Then,the optimal emulsified asphalt and their corresponding optimal spraying dosage was selected.4.When the high viscosity emulsion asphalt sand seal is placed between base and surface,inter-layer shear performance experiment was constructed and the adhesive performance was obtained.5.The mix design of high viscosity emulsion asphalt sand seal was designed,on the basis of off stone rate test,weeping phenomenon,pavement performance test,mechanical test.(1)The optimal emulsified asphalt is solid content of 70%,Ev = 10,spraying dosage 1.0kg/m2?1.2kg/m2;(2)the choice of sand species:3mm?5mm single graded limestone,spraying dosage 6.5 kg/m2?7.0kg/m2.6.In order to verify the anti-cracking of sand seal,the finite element analysis was made.Calculations show:Compare of stress at the crack-tip with and without spraying sand seal,and the former reduced by 9%-18%.Above show,high viscosity emulsion asphalt sand seal can well play a role in the conservation of the road;If crack-seal conduct was made before laying sand seal,and pavement crack tip stress reduce about 21%-45%,which shows the pre-pouring will increase the road maintenance function of high viscosity emulsion asphalt sand seal.7.The test road was paved according to the mix design,and the experimental road technical solutions,process route,the construction process was systematically studied.The survey and detection for the road conditions was also followed-up,and then technical performance was evaluated. |
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