Severely Corroded Reinforced Concrete with Cover Cracking: Part 2. Anchorage Capacity

Paper i proceeding, 2010

There is a growing need for reliable methods of assessing the load-carrying capacity and remaining service life of corroded structures. In an ongoing research by the authors, issues that have not been investigated in the methods and models available today to calculate the remaining load-carrying capacity of the corroded structures are identified. Two main issues; i.e. high amount of corrosion leading to cover spalling and the effect of corroding stirrups, were investigated in an experimental program. Pull-out tests were carried out on beam-end specimens with long embedment length to study the anchorage capacity of a corroded bar. The specimens were subjected to electrochemical corrosion process leading to different corrosion penetrations prior to mechanical loading. Details concerning electrochemical corrosion setup, corrosion-induced cracking and numerical modelling of a corroding bar are presented in a companion paper subtitled “Part 1. Crack initiation, crack propagation and cover delimitation”. Three types of specimens, with stirrups, without stirrups and with corroding stirrups, were subjected to pull-out test. The test results showed a significant influence of stirrups not only on corrosion-induced cracking but also on anchorage capacity and failure mode in the pull-out test. Finally, the corrosion and mechanical testing phases were simulated in a finite element model using the corrosion and bond models earlier developed by Lundgren [1,2]. The outcomes of the numerical modelling help to further understand the effect of high corrosion penetrations and presence of stirrups on failure modes observed in the experiments.