Analysis of bonding mechanisms of smooth and lugged FRP rods embedded in concrete

The bond behavior of two fundamental types of FRP reinforcement for concrete-smooth rods and lugged rods-has been investigated by examining experimental data and developing detailed finite-element models of these simple rod/concrete systems. The bond controlling parameters, identified by direct pull-out tests on embedded rods, were built into the models so that analytical studies of the effect of each parameter on bond could be carried out. The viability of the finite-element models, created by the use of commercial finite-element programs, was verified by comparing the predicted and experimentally obtained load versus slip and/or load versus longitudinal strain data. The models were used to predict the behavior of environmentally degraded rods. The moire' method of strain analysis was used to investigate full-field, local strain distributions in flat, lugged rods embedded on the surface of concrete. (C) 1998 Elsevier Science Ltd. All rights reserved