Influence analysis of foamed asphalt mixture gradation based on mechanical properties

In order to determine the influence and rules of the gradation of foamed asphalt on the mechanical properties, three typical gradations of foamed asphalt including the continuous gradation AC-20, the discontinuous gradation SMA-20 and the skeleton embedded crowded structure FAC-20 were taken for dry and wet splitting strength test, besides the mechanical properties of asphalt mixture under different gradations were systematically researched. The gradation composition fluctuation of four key sieve pores consisting of 0.075 mm, 0.3 mm, 1.18 mm and 4.75 mm affecting the mechanical properties of the foamed asphalt mixture gradation were systematically researched. The experimental results showed that foamed asphalt mixture was not suited for the stable discontinuous gradation; the Wittgen stable recommended gradation of foamed asphalt had better mechanical properties; the passing rate of sieve pore size bellow 0.075 mm was the key factor affecting the gradation properties of the foamed asphalt mixture, and the rate between five percent and twelve point five percent had better mechanical properties foamed asphalt mixture; the smaller sieve pore size was , the influence of the fluctuation of the passing rate on the mechanical properties of gradation was greater; among others, the 1.18 mm sieve was the critical point, the fluctuation of passing rate of sieve pore size bellow 0.075 mm affect the mechanical properties of gradation significantly.