Severely Corroded Reinforced Concrete with Cover Spalling: Part 1. Crack Initiation, Crack Propagation and Cover Delamination

In many corroding RC structures, it is not uncommon that cover spalling and delamination have occurred. Previous research has been mainly concerned with lower corrosion levels leading to cover cracking. Moreover, the main focus of the available knowledge concerns the corrosion of the main reinforcement; while the corrosion of the stirrups is often overlooked. In an experimental investigation, corrosion attack causing crack initiation, propagation and cover delamination are measured. The specimens have the shape of a beam-end and are corroded with an accelerated method. The location of the bar, middle and corner placement; the amount of transverse reinforcement; the corrosion level of longitudinal reinforcement and of transverse reinforcement are studied. The specimens after corrosion are also used in pull-out bond tests; the results are presented in a companion paper subtitled “Part 2. Anchorage Capacity”. The first test results of the ongoing experimental campaign are presented. The crack patterns are analysed, showing differences between specimens with or without stirrups and when stirrups are corroding or not. Finally, the effect of corrosion was simulated as the expansion of corrosion products in a finite element model and the results, mainly the crack pattern, were compared with the test results. The conclusions address the importance of taking into consideration both high corrosion levels and the corrosion of the stirrups for the assessment of deteriorated structures