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Cooperability
| Project leader: |
Marija Kušter Marić |
| Project co-leader: |
Joško Ožbolt |
| Administering organization: |
University of Zagreb, Faculty of Civil Engineering |
| Partner Institution/Company: |
University of Stuttgart, Institute of construction materials |
| Grant type: |
1C |
| Project title: |
Influence of concrete damage on reinforcement corrosion - computer simulation and in service performance of bridges |
| Project summary: |
Chloride-induced corrosion of steel reinforcement in concrete is the major cause of deterioration of reinforced concrete structures, especially bridges exposed to the sea and/or de-icing salts; and significantly reduces structure durability. In order to implement sustainable bridge management it is necesary to determine service life of structures using numerical models. The main aim of the project is to improve the 3D chemo-hygro-thermo mechanical (CHTM) model for realistic simulation of processes before and after depasivation of reinforcement bar in concrete.
The project includes: literature review; visual inspections and investigation works on reinforced concrete bridges combining measurements of damages in concrete, half-cell potential, electric resitivity of concrete and chloride content in concrete; laboratory testing on permeability of cracked concrete; and numerical modeling of transport and corrosion processes in reinforced concrete structures, taking into account damages in concrete.
Project activities are focused on achieving the following objectives:
• Development of an improved model of the water and chloride diffusion coefficient for concrete as a function of crack width based on the laboratory testing on permeability of cracked concrete and investigation works on the bridges;
• Determination of characteristics of the cracks and voids in concrete on the structural elements of the inspected bridges including geometry, but also causes of concrete defects;
• Determination of the structural elements of the bridges that are the most vulnerable to cracking and other damages in concrete based on the performed ultrasonic testing on the bridges and numerical modelling;
• Determination of the structural elements of the bridges that are the most vulnerable to reinforcement corrosion based on the measurements of the half-cell potential of steel rebar and electric resistivity of concrete on the existing bridges;
• Development of an empirical model of the impact of the concrete cracks on reinforcement corrosion based on the performed measurements of cracks in the concrete, electric resistivity of concrete and half-cell potential of steel rebar;
• Development of numerical models to simulate transport and corrosion processes in reinforced concrete structure including modelling of realistic cracks as well as more precisely determination of the initial and boundary conditions based on the results of the measurements on the bridges and using improved model of the chloride and water diffusivity.
New knowledge obtained from the experiments, the measurements and the numerical modelling will be useful to scientists, public sector and industry dealing with the global problem of chloride induced corrosion of steel in concrete.
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| Hrvatski sažetak: |
Kloridima izazvana korozija čelične armature u betonu je glavni uzrok propadanja armiranobetonskih konstrukcija, posebno mostova izloženih moru i/ili solima za odleđivanje, te značajno smanjuje trajnost konstrukcija. U cilju provođenja održivog gospodarenja mostovima potrebno je odrediti životni vijek konstrukcija koristeći numeričke modele. Glavni svrha projekta je unaprjeđenje 3D kemo-higro-termo-mehaničkog (CHTM) modela za realističnu simulaciju procesa prije i poslije depasivacije armaturne šipke u betonu.
Projekt uključuje: pregled literature, vizualne preglede i istražne radove na armirano-betonskim mostovima kombinirajući mjerenja oštećenja u betonu, polu-ćelijastog potencijala, električne otpornosti betona i sadržaja klorida u betonu; laboratorijska ispitivanja permeabilnosti u raspucanom betonu, te numeričko modeliranje transportnih i korozijskih procesa u armirano-betonskim konstrukcijama, uzimajući u obzir oštećenja u betonu.
Aktivnosti projekta usmjerene su na ostvarenje slijedećih ciljeva:
• Razvoj unaprjeđenog modela koeficijenta difuzije vode i klorida za beton kao funkcija širine pukotine na temelju laboratorijskog ispitivanja permeabilnosti raspucanog betona i istražnih radova na mostovima.
• Određivanje karakteristika pukotina i šupljina u betonu na konstruktivnim elementima pregledanih mostova uključujući geometriju, ali i uzroke oštećenja betona
• Definiranje konstruktivnih elemenata mostova koji su najpodložniji raspucavanju i drugom oštećenju betona na temelju provedenih ultrazvučnih mjerenja na mostovima i numeričkom modeliranju.
• Development of numerical models to simulate transport and corrosion processes in reinforced concrete structure including modelling of realistic cracks as well as more precisely determination of the initial and boundary conditions based on the results of the measurements on the bridges and using improved model of the chloride and water diffusivity.
• Razvoj empirijskog modela utjecaja oštećenja u betonu na koroziju armature na temelju provedenih mjerenja pukotina u betonu, električne otpornosti betona i polućelijastog potencijala na čeličnoj armaturi.
• Razvoj numeričkih modela za simulaciju transportnih i korozijskih procesa u armiranobetonskim konstrukcijama uključujući modeliranje realističnih pukotina u betonu te preciznijem definiranju rubnih i početnih uvjeta na temelju rezultata mjerenja na mostovima te koristeći unaprjeđeni model za koeficijent difuzije vode i klorida u betonu.
Nove spoznaje dobivene iz eksperimenata, mjerenja i numeričkog modeliranja bit će korisne za znanstvenike, javni sektor i industriju koji se bave globalnim problemom kloridima izazvane korozije u betonu.
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| Amount requested from UKF: |
300000 |
| Amount of matching funding: |
65000 |
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