The Development of Reconfigured Bond Slip Model Coefficients for CRC Pavement based on Pull-Out Testing

Abstract

The design of Continuously Reinforced Concrete (CRC) pavement consists of modeling the peak bond stress between the reinforcing steel and the concrete, which develops over time as concrete hardens due to induced loading on the reinforcement steel. The peak bond stress reflects resistance to volumetric changes between the steel and concrete as a function of the characteristics of the steel reinforcement and the properties of the concrete. Even though bond model parameters have been defined in the literature by many researchers, these parameters have not been well determined. This paper addresses the development of reconfigured bond slip coefficients included in the Reis bond model based on the parameters that reflect peak bond stresses relative to slip between the reinforcement and concrete. The data for the model was developed from laboratory-fabricated pullout specimens that were subjected to cyclic tensile testing at several stress levels. The peak bond stress and changes in a parameter referred to as bond stiffness were found to be a function of the tensile stress level and the threshold of slip. Based on the pullout testing results, the Reis slip coefficients were ultimately validated using field-measured crack spacing and width data. The revised bond model coefficients were the basis for revised crack spacing and crack width determinations applicable to the AASHTOWare Pavement ME (PMED) software.