The time series of fluctuating pressure signals under different experimental conditions were measured by a pressure transducer,and a novel method for measuring gas holdup in bubble column was proposed,namely,the local gas holdup was estimated by resorting to local intermittency measurement(LIM)method and multi-resolution analysis of the time series of fluctuating pressure signals.

In order to improve anti-rut ability of AC-20 modified asphalt mixture in asphalt pavement engineering,this paper investigates the influence of the gradation and different OAC of AC-20 modified asphalt mixture on Marshall performance standards with the help of Marshall orthogonal design methods and variance analysis,and the optimum aggregate gradation engineering design of AC-20 is put forward.