Tensile strength and slip model for steel reinforcement anchorages and lap splices

A unified analytical model to compute the slip response and maximum tensile stress capacity of both steel bar anchorages and lap splices is presented. The model assumes idealized bond stress distributions along the anchorage and lap-splice lengths, from which tensile stress-slip relations are derived to characterize their deformation response. A simple bond failure criterion is also established to compute the tensile strength of the anchorage or lap splice, considering potential pullout and splitting failures. The ability of the proposed model to determine the force-deformation response of anchorages and lap splices is verified using experimental data from pullout tests and uniaxial tests on lap splices reported in the literature, and its accuracy for predicting tensile strength is evaluated with results from 457 tests of the ACI 408 database on lap splices. The calibration of the model is refined using a Bayesian estimation framework, which compares analytical results obtained using randomly generated samples from estimated parameter distributions to experimental data from the lap-splice database. The resulting mean value of the experimental-to-analytical strength ratios for the lap-splice tests is practically equal to 1 and the coefficient of variation is 0.20. Based on the results of Bayesian estimation, probabilistic distributions are also proposed to quantify the uncertainty of key model parameters.