Updating of the corrosion degree based on visual data combined with strain or modal data

Many existing bridges are reaching the end of their technical service life. To estimate the remaining lifetime of reinforced concrete structures, it is important to assess the parameters of the corrosion process (i.e. parameters governing the corrosion propagation, but also parameters of the chloride or carbonation ingress). The level of corrosion and its spatial distribution can be inferred from strain data under static loading or modal data. In addition, information from visual inspections is often available as well, although not often used to quantify the level of corrosion. In this work, it is investigated how visual inspections can supplement the strain and/or modal data and provide information on corrosion parameters. The developed framework is applied to a simply supported beam subjected to corrosion.Many existing bridges are reaching the end of their technical service life. To estimate the remaining lifetime of reinforced concrete structures, it is important to assess the parameters of the corrosion process (i.e. parameters governing the corrosion propagation, but also parameters of the chloride or carbonation ingress). The level of corrosion and its spatial distribution can be inferred from strain data under static loading or modal data. In addition, information from visual inspections is often available as well, although not often used to quantify the level of corrosion. In this work, it is investigated how visual inspections can supplement the strain and/or modal data and provide information on corrosion parameters. The developed framework is applied to a simply supported beam subjected to corrosion.C

Development of conformity criteria for diffusion coefficients of concrete and their influence on the service life of reinforced concrete structures

Conformity control is often applied on concrete compressive strengthin order to safeguard the quality of produced concrete lots. Conformity criteriaare mostly characterized by an operating characteristic curve, indicating theprobability of acceptance in relation to a concrete lot with a specific quality. Byapplying this conformity control, certain lots of concrete are accepted and othersare rejected. This induces a filtering effect, leading to an effect on the failureprobability as a result of the quantitative quality control process.For durability criteria, often limiting bounds for durability related propertiesare proposed. Specifying conformity criteria for example to the diffusion coefficientof the concrete can enable to safeguard the quality of concrete products inrelation to durability properties. Also this type of conformity control has a filteringeffect, i.e. on the distribution of the diffusion coefficient, resulting in a lowermean value and standard deviation, influencing consequently the service life. Thispaper investigates for the first time the effect of conformity criteria for diffusioncoefficients as well their effect on the service life of concrete elements.Conformity control is often applied on concrete compressive strengthin order to safeguard the quality of produced concrete lots. Conformity criteriaare mostly characterized by an operating characteristic curve, indicating theprobability of acceptance in relation to a concrete lot with a specific quality. Byapplying this conformity control, certain lots of concrete are accepted and othersare rejected. This induces a filtering effect, leading to an effect on the failureprobability as a result of the quantitative quality control process.For durability criteria, often limiting bounds for durability related propertiesare proposed. Specifying conformity criteria for example to the diffusion coefficientof the concrete can enable to safeguard the quality of concrete products inrelation to durability properties. Also this type of conformity control has a filteringeffect, i.e. on the distribution of the diffusion coefficient, resulting in a lowermean value and standard deviation, influencing consequently the service life. Thispaper investigates for the first time the effect of conformity criteria for diffusioncoefficients as well their effect on the service life of concrete elements.C