An Initial Effort to Use the Corrosion Rate Measurements for Estimating Rebar Durability

Abstract

The approach presented here is an attempt to implement the values of corrosion intensity which have been measured in laboratory tests, in the framework of the service life prediction analysis for corroding structures. First of all, the model on service life suggested by Tuuti was considered, and only the propagation period model has been analyzed in this paper. In order to expand the proposal, different steps were covered: (1) the definition of an unacceptable level of deterioration, taking into consideration the levels suggested by the Comité Eurointernational du Béton (CEB) in its Bulletin No. 162, in order to define the urgency of intervention in a damaged structure; (2) the reduction in bar diameter or bar section was taken as the determining parameter in failure risk, assuming that this decrease in section occurs either in a generalized form or in the zones of the structure in which the load-carrying capacity may be significantly affected; and (3) the ranges of possible corrosion intensity values were introduced in Tuuti's model for calculating the reduction in bar section in function of the life of the structure. Some examples for bars of 10 and 20 mm ϕ were presented. Finally, the limitations and the improvements of the proposal are discussed.

Bond Deterioration of Reinforcing Steel in Concrete Due to Corrosion

“…This investigation agrees weB with the results of the study by Andrade et al (1990), who suggested that a reduction of lOto 25 percent in the bar section in the critical zones of the structure will result in the depletion of its service life, while a reduction up to 5 percent, even with cracking and spalling, will indicate an early stage of deterioration with the remaining service life not as significantly influenced, provided that adequate repairs are undertaken urgently.…”

“…Mass losses up to 5 percent can cause the element to crack and spall, however, this is an early stage of deterioration with the remaining service life not as significantly influenced, provided that adequate repairs are undertaken urgently. However, a 10-25 percent mass loss in the critical zones of the structure will result in the depletion of its service life (Andrade et al 1990). …”

Corrosion susceptibility of steel drums to be used as containers for intermediate level nuclear waste

“…CR were calculated using the expression CR=k.B/R p where B is a constant that depends on the active/passive state of the steel: B is equal to 0.026 V, in the case the steel is in the active state, and 0.052 V in the case of passive state [10]. k is a constant that relates corrosion current densities and CR by applying Faraday´s Law [k= 11.6 (µm/year)/(µA/cm 2 )].…”

Particle filtering based structural assessment with acoustic emission sensing

“…For corrosion propagation, Andrade et al [21] employed the Tuutti conceptual model to estimate the loss in reinforcing bar cross section during the propagation period as:…”