Study On The Vibration Mixing Technology Of OGFC Asphalt Mixture

OGFC asphalt mixture has the characteristics of high voidage,large structure depth,high friction coefficient and strong water permeability.In rainy days,it has good drainage performance and anti-skid performance,and also has the function of absorbing tire noise so as to reduce traffic noise pollution.Also due to its high voidage structure characteristics,the asphalt mixture under the long-term action of air and water is easy to produce water damage,resulting in aggregate loose spalling and other early diseases.At present,most of the ways to improve the performance of OGFC asphalt mixture are from the material and grading,while there are relatively few ways to improve the performance of OGFC asphalt mixture from the mixing process.Based on this,starting from the thixotropy theory and shear thinness characteristics of modified asphalt,this study studied the influence of different vibration action on the performance of modified asphalt and the influence of different parameters of vibration mixing on the performance of OGFC asphalt mixture,so as to explore a new way to improve the performance of OGFC asphalt mixture.In this paper,the existing equipment is firstly innovated and improved to make a set of device which can measure the viscosity of asphalt in a variety of temperature,vibration frequency,vibration amplitude and vibration time in real time.And this device is used to study the change of viscosity of four modified asphalt under different vibration states in combination with the actual production conditions.Secondly,the basic performance of asphalt before and after vibration is studied through three index tests of asphalt.The results show that the viscosity of the four modified asphalt samples decreases with the addition of vibration,and the viscosity reduction rate increases with the increase of asphalt temperature,amplitude and frequency.Before and after vibration,the three indexes of the four modified asphalt samples remain basically unchanged.Finally,according to the material of the actual project,the OGFC-13 asphalt mixture is designed.And according to the mixture ratio,the OGFC-13 asphalt mixture is prepared by vibration mixing with different vibration parameters.Its functional performance and road performance are detected.And the relationship between vibration mixing and the performance changes of OGFC asphalt mixture in all aspects is studied.Results show that the OGFC asphalt mixture performance of ascension with the augmentation of the vibration effect,under the same grading and oil-stone ratio,vibratory mixing reduce OGFC asphalt mixture draindown.High temperature stability improvement.Raveling is reduced.Water stability improvement.Increase connected under the condition of invariable in void fraction void fraction.Enhance the ability of water seepage of the mixture.However,there is an upper limit for the performance improvement of OGFC asphalt mixture by vibration mixing.After the vibration frequency reaches 40 Hz,the performance of the mixture does not continue to improve,although the vibration effect continues to increase,the asphalt fluidity continues to increase,and the vibration movement of aggregate continues to increase.Therefore,the optimal vibration frequency of OGFC-13 asphalt mixture is recommended to be 40 Hz under the vibration stirring condition of stirring temperature 185℃ and amplitude 2mm.