Research On Basic Mechanical Performance Of Fiber Recycled Brick Aggregate Concrete

Fiber recycled brick aggregate concrete refers to recycled aggregate for the base material and in which mixed with fiber and made of new fiber reinforced ecological material. Fiber recycled brick aggregate concrete as a new type of ecological material,can overcome the low strength, poor ductility, easy cracking and other defects of traditional ecological material, greatly improve the tensile strength and its durability.This new material is not only reasonable construction waste has been utilized to achieve the sustainable development and protection of resources on the environment, but also solve the problem of demand for new building materials. In order to make this new material could better use for the actual project, the paper adopts the method of test and theoretical analysis, proposed the basic mechanical properties of fiber recycled concrete brick and the compression constitutive model for research, the main contents of the paper are as follows:(1) In this paper, polypropylene fiber and steel fiber are selected to develop polypropylene fiber recycled brick concrete and steel fiber recycled brick concrete, and the method of orthogonal experiment is adopted to discuss the effects of water-cement ratio, aggregate replacement ratio and fiber content on the properties of the fiber reinforced concrete, then optimize its composition and proportion, initially identified fiber regeneration process optimum combination of the fiber recycled brick aggregate concrete.The results showed that: For polypropylene fiber recycled brick concrete cube compressive strength and cube splitting tensile strength, the influences of various factors are in the order of water-cement ratio > fiber content > aggregate replacement ratio. For steel fiber recycled brick concrete cube compressive strength, the influencesof various factors are sequentially arrayed as water-cement ratio > fiber content >aggregate replacement ratio, for steel fiber recycled brick concrete cube splitting tensile strength, the influences of various factors are sequentially arrayed as fiber content>water-cement ratio > aggregate replacement ratio.(2) The paper adopts the single-factor experiment to study the process of compression failure and the crack pattern, then it studys the influence of fiber content to the axial compressive strength, the elastic modulus, the relationship between the two strength of the fiber recycled brick aggregate concrete, that is determine the ratio coefficient between axial compressive strength and cubic compressive strength and the empirical formula between splitting tensile strength and cubic compressive strength of the fiber recycled brick aggregate concrete. The results showed that:Fiber can improve the axial compressive strength of the fiber recycled brick aggregate concrete, but it is not obvious, fiber can reduce the elastic modulus of the fiber recycled brick aggregate concrete.(3) The paper adopts the single-factor experiment to study the axial compressive of prisms and its compressive stress-strain curve of polypropylene fiber recycled brick concrete and steel fiber recycled brick concrete, and then analysis the influence of fiber content to the curve and its parameters and puts forward the corresponding constitutive model of compression, and gives the damage constitutive model of fiber recycled brick concrete brick based on damage theory and studys the damage evolution of the curve.The results showed that : Fiber can effectively inhibit the development of the cracks,improve the deformation capacity of concrete, improved the toughness of concrete,inhibit the development of concrete damage.