Experimental Study On High Performance Recycled Aggregate Concrete’s Shear Fracture (Ⅱ) Performance

With the development of recycled aggregate’s application, the more andmore research on basic performance of recycled aggregate. The paper arediscussed recycled aggregate gradation fractal dimension, High PerformanceRecycled Aggregate Concrete’s, basic mechanical properties, shear fractureperformance with experimental study, and measured fractal dimension ofshear section. The conclusions are drawn as followings:(1) Recycled coarse aggregate have particle size distribution andgradation distribution of obvious fractal feature. The diameter fractaldimension and the gradation fractal dimension decreased with the recycledaggregate replacement ratio’s increased; its value is in the range of2to3.(2) The slump and tensile strength, compressive strength of HighPerformance Recycled Aggregate Concrete are decreased with the recycledaggregate replacement ratio’s increased; The diameter fractal dimension,gradation fractal dimension are proportional to tensile strength andcompressive strength.(3) The experimental are effected loading point from the distance ofprefabricated crack, smooth degree of specimens and so on. There are threedifferent mode of shear fracture and unilateral crack development. There arenot linear relationship of recycled aggregate replacement ratio with ultimateload and fracture angle and fracture energy and fracture toughness; thefracture angle is in a range from60°to72°. The specimens was happenedinstantly fracture failure, and the curve of P-Δu reached limit value, when thesystem was ultimate load. The Ⅱ type was than large Ⅰtype about20to30times, there are not linear relationship between the basic parameters andcompressive strength、 tensile strength.(4) The fractal dimension increased with the recycled aggregatereplacement ratio, the results indicate that the surface fractal dimension of Recycled High Performance Concrete is in a range from2to3. Therelationship between the fracture surface dimension of RHPC its compressivestrength is inversely proportional, the linear equation is y=-423.796x+895.675,the curve regressions were established with high correlation.(5) We are analysis the technical and economic performance index withSet Pair Analysis; and provide a way for evaluation, get an ideal target ofindexes. This paper’s ideal group is25%to50%.This paper analysis basic performance with four-point shear fracture, andmeasure fracture mechanical of basic parameters. But there are many factorsthat are effecte this experimental for size effect, cement ratio, differentintensity, different replacement ratio, different loading ratio and so on.