Bond response in structural concrete with corroded steel bars. Experimental results

The 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 finding

CO2 Sink Effect Of Concrete Carbonation Spain

Although carbonation of cement phases is well known, the amount of carbon dioxide combined during the process has been much less investigated. Related to the greenhouse effect much more attention is being paid to the sinks for C 0 2 in order to correctly compute the gases emission during production of materials. In the case of cement a strict calculation should discount the C 0 2 emitted from that fixed by the concrete. This is the aim of present work which is a study of the cement based materials ability to combine C 02. Using Thermogravimetry and Differential Thermal Analysis as well as phenolphthalein indicator, quantities of C 0 2 combined and carbonation depth in several cement pastes and concretes exposed to different environments have been measured. A calculation to estimate the contribution of cement based materials carbonation to the partial re-absorption of the C 02 emitted in cement production is proposed

Estudio del efecto sumidero de CO2 de los materiales de base cemento

Estudio del efecto sumidero de CO2 de los materiales de base cement

Experimental and numerical study of bond response in structural concrete with corroded steel bars

Corrosion can affect the bond between reinforcing bars and concrete and hence the transfer of longitudinal stresses. Although a number of experimental studies on bond failure have been conducted in recent years, the findings have diverged rather widely, due primarily to differing test conditions. The present paper reports on an experimental programme consisting of eccentric pull-out tests run on corroded steel bars in specimens subjected to accelerated or natural corrosion. An axisymmetric bi-dimensional FE model with finite deformations initially developed to study bond mechanics with sound steel bars, has been enhanced to consider bond effects in corroded steel bars. The model simulation is compared to some of the experimental results for corroded and sound bars and the findings are analysed