Korozija betonskih stupova armiranih različitim vrstama čelika nakon dugotrajnog izlaganja realnom morskom okolišu

master's thesis

• Title (english): Corrosion of concrete columns with different steel reinforcement after long-term exposure to real marine environment
• Author: Eva Zimprich
• Mentor: Marijana Serdar (mentor)
• Committee member: Marijana Serdar (predsjednik povjerenstva)
• Committee member: Marijan Skazlić (član povjerenstva)
• Committee member: Nina Štirmer (član povjerenstva)
• Granter: University of Zagreb; Faculty of Civil Engineering; (Materials); Zagreb
• Defense date and country: 2022-09-29, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Civil Engineering

Abstract

Korozija čelika najčešći je uzrok prijevremenog propadanja i skraćivanja uporabnog vijeka armiranobetonskih konstrukcija. Ogromni troškovi i sigurnosna pitanja povezana s korozijom čelika u betonu rezultirala su razvojem širokog spektra tehnologija i materijala kako bi se povećala trajnost armiranobetonskih konstrukcija. Jedna od metoda, kojima se odgađa ili u potpunosti sprječava pojava korozije, je korištenje određenih vrsta korozijski otpornih čelika s nižim udjelom legirajućih elemenata, koji su otporniji na koroziju od ugljičnog čelika, dok im je cijena značajno niža od nehrđajućih čelika. Cilj ovog rada bio je provesti analizu korozijskog procesa na armiranobetonskim stupovima koji su 10 godina bili izloženi realnom morskom okolišu podno Krčkog mosta. Stupovi su bili armirani različitim vrstama čelika, a svaki stup se sastojao od 2 šipke od ugljičnog čelika i 2 šipke od korozijski otpornih čelika. U radu su provedena ispitivanja na ukupno pet vrsta armaturnih čelika: na ugljičnom čeliku (B500B), na feritnom čeliku (TOP12), austenitnom čeliku s većim udjelom nikla (304L), austenitnom čeliku s manjim udjelom nikla (204Cu), dvije vrste dupleks čelika (1.4362, 2205). Na pojedinoj vrsti čelika analizirao se korozijski proces s ciljem istraživanja utjecaja vrste legura na dugotrajno ponašanje čelika u morskom okolišu. Također je bilo potrebno ustanoviti utjecaj nehrđajuće armature na brzinu korozije obične armature od ugljičnog čelika, kada se iste nalaze unutar betonskog stupa. Istraživanja u ovom radu provedena su uz pomoć optičkog 3D skenera, kojim je omogućeno automatizirano analiziranje korozijskih napada na različitim vrstama čelika.

Abstract (english)

Steel corrosion is the most frequent cause of early deterioration and shortening of service life of reinforced concrete structures. Huge costs and safety issues related to steel corrosion in concrete resulted in development of a wide range of technologies and materials in order to increase the durability of reinforced concrete structures. One of the methods, which delay or fully prevent corrosion, is the use of certain types of corrosion resistant steel with lower alloying elements, which are more corrosion resistant than carbon steel, while their price is significantly lower than stainless steel. The aim of this thesis was to analyse the corrosion process on reinforced concrete columns that were exposed for 10 years to the real marine environment below the Krk bridge. The columns were reinforced with different types of steel, and each column consisted of 2 carbon rebars and 2 corrosion-resistant rebars. Tests were carried out on total of five types of reinforcing steel: carbon steel (B500B), ferritic steel (TOP12), austenitic steel with higher nickel content (304L), austenitic steel with lower nickel content (204 Cu), and two types of duplex steel (1.4362, 2205). The corrosion process was analyzed on a particular type of steel with the aim of investigating the influence of the type of alloy on the long-term behavior of steel in the marine environment. It was also necessary to establish the influence of stainless steel reinforcement on the corrosion rate of ordinary carbon steel reinforcement, when it is placed inside the same concrete column. The research in this work was carried out with the help of an optical 3D scanner, which enabled the automated analysis of corrosion attacks on different types of steel.

• Keywords: Korozija; korozijski otporni armaturni čelici; morski okoliš; smanjenje promjera armature; 3D skener
• Keywords (english): corrosion; corrosion resistant steel; marine environment; loss of cross section; 3D scanner
• Language: croatian
• URN:NBN: urn:nbn:hr:237:214049
• Study programme: Title: Civil Engineering; specializations in: Construction Management, Transportation Engineering, Geotechnical Engineering, Hydraulic Engineering, Structural Engineering, Construction Materials, Theory and Modeling of Structures; Course: Construction Management; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka građevinarstva (magistar/magistra inženjer/inženjerka građevinarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2023-01-30 10:31:03