Constitutive Research Of Crumb Rubber Concrete

Comparing to plain concrete, crumb rubber concrete, which is widely used in highway, bridge, railway , civil architecture and military building, has small quality and good performance of durability, shock absorption and sound insulation, At present, the research of crumb rubber concrete is mostly fastened on performance of application. Founding consummate system info and research method of experience will promote the usage of crumb rubber concrete. This paper studies the constitutive relation of crumb rubber concrete and uses finite element method to work over, and the results are shown as follows.Uniaxial compression experiment for crumb rubber concrete (CRC) is studied in this paper. The influence of the size and the content of the crumb rubber on the compression strength is also investigated, and the calculation formula for the compression strength of CRC is presented. Based on the stress-strain curves of CRC with different sizes and different contents and "Code for design of concrete structure" for unxial axis nonlinear elastic constitutive modal of concrete, the constitutive equations of CRC are established including a parameter based on the least two multiplication analysis of stress-strain curves of CRC, and the constitutive parameter A was calculated. The relationship between the constitutive parameter A and crumb rubber sizes and contents was presented. The constitutive parameter A decreases with the increase of crumb rubber content, and it decreases with the decrease of the size of the crumb rubber.Fuller formula is used to translate three dimensional particle grades into probability of arbitrary aggregates diameter in two dimensional plane. Crumb rubber concrete (CRC) is dispersed as a structure with three phrases composite materials, coarse aggregates, rubber crumbs and mortar. The randomly distribution model of coarse aggregates and rubber crumbs is generated. Normal concrete is made up of aggregates and mortar matrix. CRC is assumed to be composite material of two phases with concrete and rubber crumbs. The finite element method is employed to simulate the uniaxial compression strength. The results accord with those of the experiment well. It is demonstrated that the numerical method can be used to forecast the strength of CRC in uniaxial load approximately. The stress distributions in the micro level structure of CRC are presented, which can explain the mechanics behavior of CRC in uniaxial condition.