Model of Uniaxial Stress-Strain Relation of Concreteby Multi-Parallel-Bars System
LI Min, ZHAO Jun(College of Civil and Architectural Engineering, Henan University, Henan Kaifeng 475001, China)
The mechanism of damage and softening of concrete under uniaxial compression is analyzed in the light of fracture mechanics; it is found that the bending and breaking due to the buckling of the cleaving crack surfaces are the major causes. A multiparallelbars model is developed to describe the above mechanism and a related damage index is initiated based on this model. The model parameters of some prime and confined concrete of ordinary strength grades are determined. Comparison of bars distribution features and their causes are made among different kinds of concrete.