Research On The Effect Of Aggregate Gradation On The Performance Of Core Wall Asphalt Concrete

Asphalt concrete as the earth dam seepage control system has been widely used in xinjian.Previous design are complex,and it is strict in grading of aggregate during the practical engineering.In this paper,considering from two aspects the largest diameter and aggregate deviation.Analyzes concrete mechanics performance differences between the largest aggregate diameter of 19 mm and 26.5 mm,as well as the different graded aggregate grading deviation`s affection to the performance of asphalt concrete,and finally gets the regularity of some core wall of asphalt concrete materials.The main research results are as follows:?1?Studied?9<sup>2</sup>6.5?mm particle concentration,concentration of filler,and sphalt content`s influence to Marshall stability,flow value and the effect of splitting tensile strength of asphalt concrete wall by orthogonal test.The results showed that:with the?9²6.5?mm particle concentration increase of Marshall stability and flow values increase with the decrease of the first,splitting tensile strength increases after the first stable;With the increase of filler concentration Marshall flow value and splitting tensile strength increases first and decreases,and Marshall stability decreases;With the increase of dosage of asphalt,Marshall flow value increases gradually,Marshall stability and splitting tensile strength decreases.?2?Draw the Marshall stability,flow value and splitting tensile strength of the contour map,and three maps to do coincidence analysis:?19²6.5?mm particles accounted for 40%of particles?9.5²6.5?mm,filler concentration is 2.0,asphalt content of 6.8%,core wall Marshall stability,flow value of asphalt concrete and splitting tensile strength to achieve the optimal.?3?By Penetration test:D_max=26.5mm is larger than D_max=19 mm on permeability coefficient 2.4 x10-10 cm/s,relative difference is 3.6%,the difference is not obvious,and can meet the requirements of anti-seepage.?4?Through mechanics test compares D_max=26.5mm with D_max=19 mm of their mechanical properties of asphalt concrete and shows:D_max=26.5 mm is lower than the compressive strength of D_max=19 mm0.08 MPa,the relative difference is 8.7%,the difference is not obvious;While small tensile strength 0.21MPa,relative difference is 38.2%,comparatively large difference;This suggests that the aggregate particle size of the largest influence on the compressive properties of asphalt concrete is not big,but had a greater influence on the tensile properties,and the particle size,the greater the tensile performance is poorer.?5?Under four different confining pressure,D_max=26.5mm`s deviatoric stress are bigger than D_max=19mm when it is damaged and under the condition of high confining pressure,D_max=26.5 mm is also bigger in the body.It Illustrate aggregate particle size is larger,the higher the shear strength of asphalt concrete,volume expansion,the more obvious.?6?To study the distribution of each grade deviation of asphalt concrete wall mechanics performance by projection pursuit regression analysis method,the results show that:?4.75⁹.5?mm fraction has the biggest influence on Marshall stability;graded?4.75⁹.5?mm and?2.36⁴.75?mm have the same effects on splitting tensile strength;graded?9.5¹9?mm and?2.36⁴.75?mm have the same effects to Marshall Rhe influence degree.?7?By grading deviation test result:the wall of asphalt concrete mechanics performance influence degree of graded?4.75⁹.5?mm,graded?9.5¹9?mm,graded?2.36⁴.75?mm,graded?0.075².36?mm.Therefore,in the practical engineering field test personnel should control?4.75⁹.5?mm graded grading deviation strictly to ensure construction quality.