Simulating bond-slip effects in high-performance fiber-reinforced cement based composites under cyclic loads

Ductile High-Performance Fiber-Reinforced Cementitious Composites (HPFRCCs) have been explored experimentally for new construction and retrofit strategies by numerous researchers; however, modeling tools are not yet able to fully predict and validate the behavior of HPFRCC components under cyclic loads. Most models of HPFRCC structural elements ignore bond stress and reinforcement slip (bond-slip) behavior, a phenomenon that is known to account for pinching and strength degradation, among others effects, in ordinary reinforced concrete members. In this paper, recently acquired experimental bond-slip data is incorporated into finite element simulations of an HPFRCC flexural member to predict performance under cyclic loading conditions, and results are compared to experimental behavior. Results show that including bond-slip behavior can improve the accuracy of simulated flexural strength and stiffness. The need for including bond-slip in simulations of HPFRCC elements is highlighted when comparing simulated deformation levels that cause fracture of the reinforcement to those observed experimentally. Additional comaprisons are made on how specimen geometry from tensile experiments may need to be considered in simulations.