Bond Response in Structural Concrete with Corroded Steel Bars. Experimental Results

Trabajo presentado en el Joint fib-RILEM Workshop Modelling of Corroding Concrete Structures, celebrado en Madrid (España), los días 22 y 23 de noviembre de 2010The growing interest in upgrading existing reinforced concrete structures or extending their service life, and in ensuring greater durability in new designs, has led to a need for resistance models that take deterioration processes into account to verify structural safety. Bond activation between reinforcing steel and concrete is of cardinal importance in this context. A number of experimental studies have been conducted in recent years on bond failure, which normally leads to brittle behaviour. The findings have diverged rather widely, however, due primarily to differing test conditions. The present paper presents an experimental programme for eccentric pull-out tests in which specimens were subjected to both accelerated and natural corrosion in an attempt to surmount these inconsistencies. It also introduces an embedded fibre-optic sensing system with corrosion-resistant fibre Bragg grating sensors and discusses some of the findings.Peer reviewe

Effects of Corrosion and Ribs on Low Cycle Fatigue Behavior of Reinforcing Steel Bars S400

The results of an experimental study for assessing the degradation of the fatigue properties of reinforcing steel bars grade S400 caused by exposure to laboratory salt spray corrosion environment are presented. For this purpose, low cycle fatigue (LCF) tests were carried out. Furthermore, the effect of ribs on the fatigue strength was recorded. Results are indicative of the catalytic impact of corrosion on LCF behavior. Since two important degradation factors such as corrosion and LCF are functions of time, it appears that the reliability of steel S400 is also time dependant. Additionally, the presence of ribs on material's surface affects significantly the fatigue behavior by reducing energy dissipation and duration of test