Estimation of bond strength envelopes for old-to-new concrete interfaces based on a cylinder splitting test

The number of existing structures under rehabilitation has significantly increased over the past two decades; these structures typically require performance improvements including repair and strengthening. Currently, reinforced concrete is widely used in interventions for the rehabilitation of bridges and buildings. Here, we present a method for the estimation of failure envelopes for old-to-new concrete interfaces based on plasticity theory. The proposed Carol-type failure envelope uses the simple splitting tension test, also known as the Brazilian test. The relevant parameters of the envelope—ft′, the tensile strength, c′, cohesion and ϕ′, the friction angle—are assessed by experimentation, a rational formulation and a bibliographic study, respectively.