Development of a New Constitutive Model for Analysis of RC Elements Retrofitted with FRP


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Title: Development of a New Constitutive Model for Analysis of RC Elements Retrofitted with FRP

Author(s): Yashar Moslehy, Moheb Labib, T. R. S. Mullapudi, and Ashraf Ayoub

Publication: Special Publication

Volume: 301


Appears on pages(s): 1-18

Keywords: Softening Coefficient, Reinforced Concrete, FRP Strengthening, Shear, Constitutive Laws

Date: 3/16/2015

Fiber-reinforced Polymer (FRP) started to find its way as an economical alternative material in civil engineering from the early 1970s. The behavior and failure modes for FRP composite structures were studied through extensive experimental and analytical investigations. While research related to the flexural behavior of FRPstrengthened elements has reached a mature phase, studies related to FRP shear strengthening is still in a less advanced stage. In all proposed models to predict the shear capacity, the constitutive behavior of concrete and FRP was described independently. The true behavior, however, should account for the high level of interaction between the two materials. In this research, new constitutive relations for FRP-strengthened reinforced concrete elements subjected to pure shear are developed. In order to generate these relations, large-scale tests of a series of FRPstrengthened reinforced concrete panel elements subjected to pure shear are conducted. The University of Houston is equipped with a unique universal panel testing machine that was used for this purpose. These constitutive laws are implemented into fiber-based finite element models to predict the behavior of externally bonded FRP strengthened beams. The newly developed model proved to provide a good level of accuracy when compared to experimental results.