Value of Information (VoI) for the Chloride Content in Reinforced Concrete Bridges

Abstract

The corrosion of reinforcement caused by chloride ingress significantly reduces the length of the service life of reinforced concrete bridges. Therefore, the condition of bridges is periodically inspected by specially trained engineers regarding the possible occurrence of reinforcement corrosion. Their main goal is to ensure that the structure can resist mechanical and environmental loads and offer a satisfactory level of safety and serviceability. In the course of assessment, measuring the chloride content, through which corrosion could be anticipated and prevented, presents a possible alternative to visual inspections and corrosion tests that can only indicate already existing corrosion. It is hard to determine the cost-effectiveness and actual value of chloride content measurements in a simple and straightforward way. Thus, the main aim of the paper was to study the value of newly gained information, which is obtained when a chloride content in reinforced concrete bridges is measured. This value was here analyzed through the pre-posterior analysis of the cost of measurement and repair, taking into account different types of exposure and material properties for a general case. The research focus was set on the initiation phase in which there are no visible damages. A relative comparison of costs is presented, where the cost of possible reactive/proactive repair was compared with the maximum cost of measurement, while the measurement is still cost effective. The analysis showed a high influence of the initial probability of depassivation on the maximum cost of the cost-effective measurement, as well as a nonreciprocal relation of the minimum cost of cost-effective reactive repair with the measurement accuracy.

Durability of Gerber Saddles in RC Bridges: Analyses and Applications (Musmeci Bridge, Italy)

“…As for C s , both non-destructive and destructive tests are available. Among many available methods, the application of ion-selective electrodes or optical fibre sensors [33] are NDT methods while the Volhard method [34] is a widely used chemical technique needing samples of concrete to be taken from the structures. Several experimental methods are also available for the estimation of D re f being of destructive type since concrete cores are necessary for laboratory testing.…”

Ansätze zur performancebasierten Zustandsbeurteilung und Lebensdauerprognose von Ingenieurkonstruktionen

“…In der Stufe II sind somit die erweiterten KI‐Expertensysteme, wie Markovketten‐Ansätze [8] und Gamma‐Prozesse [7], für umfangreichere und komplexere Performancevorhersagen nutzbar, da sich z. B. die Übertragungswahrscheinlichkeiten der Markovketten und die Form‐ und Skalierparameter der Gamma‐Prozesse mit den über Monitoring dokumentierten Zustandsänderungen der Struktur kontinuierlich anpassen lassen.…”

“…Das Sicherheitsindexkonzept lässt sich auch in das folgende Nachweisformat entwickeln: In dieser Modellstufe III sind erweiterte KI-Expertensysteme, wie Markovketten-Ansätze [8] und Gamma-Prozesse [7], für die umfangreicheren und komplexeren Performancevorhersagen als begleitend zu sehen, wesentlich wichtiger ist die enge Verknüpfung der Test-und Monitoringdaten sowie der Informationen aus den visuellen Inspektionen zu den Digital-Twin-Analysen. Diese Verknüpfung basiert auf innovativen, kontinuierlich durchgeführten Bayesian-Updating-oder neuronal-netzwerkbasierten Updating-Verfahren.…”

Sensitivity Analysis of Stochastic Calculation of SCC Regarding Aggressive Environment

“…Many of them use the finite element method (FEM) in combination with probabilistic methods. Probabilistic calculations of the durability of concrete structures influenced by the aggressive substances play an important role [22][23][24]. The probabilistic FEM solution is quite common for the assessment of static properties of civil engineering structures [25][26][27]; however, it is not very common to extend it to the durability area, and therefore many questions remain open in this field of science.…”