A damage constitutive model for multi-scale polypropylene fiber concrete under compression and its numerical implementation

Multi-scale polypropylene fiber concrete has been put into use in the enhancement of structures such as bridges, wharfs, and road surfaces. This paper makes experimental study on the cube compressive strength of polypropylene fiber concrete with different slenderness ratios, and studies its improvement of the cubic compressive strength of concrete through mixed admixture of polypropylene fibers with different degrees of thicknesses. The experimental results show that: the cubic compressive strength of the concrete improved by 6.2-13.7% with single and mixed admixtures of polypropylene fibers. In addition, this paper builds on previous studies to establish a damage constitutive model of multi-scale polypropylene fiber concrete under compression, studies its application in the secondary development of FLAC(3D) software, and makes numerical simulation based on the developed model, whose calculation results accorded with the test date very well.