Author(s): Stefan Kubens; Juan Mauricio Lozano-Valcarcel; Thomas Krankel; Amir Rahimi; Christoph Muller; Christoph Gehlen

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Keywords: concrete; material; durability; hydraulic structures; sustainability

Abstract: In current codes the durability of concrete structures is usually guaranteed by describing mix design parameters, particularly the maximum water to cement ratio and the minimum cement content and by specifying the minimum concrete cover in dependency of the exposure conditions. European and German standards specify relevant requirements. However, the performance-based approach, which specifies the material’s resistance against environmental impact, is getting more and more prominent. Hence, a research project was initiated to assess the reliability of structures planned and built according to current descriptive concept in German standards. Three types of structures were investigated: bridges, regular structures and hydraulic structures. This article covers the hydraulic structures. The structures investigated were four lock chambers in service for 10 to 13 years. The aim of the inspections was to come up with information about material performance and execution quality. Material tests were carried out in situ and in the laboratory. The in-situ investigations included the visual inspection of concrete surfaces, the measurement of concrete cover, the measurement of scaling and of carbonation depth. The laboratory tests were carried out on concrete cores taken during the inspections to determine the performance of the concretes used. The laboratory testing included compressive strength, carbonation depth, air void system in hardened concrete and freeze-thaw-tests. Based on the in-situ investigations and laboratory tests an evaluation of the structures is carried out regarding their durability for the target service life of 100 years.

DOI: https://doi.org/10.3929/ethz-b-000675921

Year: 2024