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Long-term performence of cathodic protection (CP) of marine bridge, inspection of Sortlandsbrua 27 years after CP installation.
No full textLong-term performence of cathodic protection (CP) of marine bridge, inspection of Sortlandsbrua 27 years after CP installationConcrete structures placed in or next to the sea are constantly bombarded with chlorides,
either directly from the seawater or by airborne chlorides. This can cause ingression of
chlorides on to the surface of the reinforcement of the concrete which then may start to
corrode. There are more than 7000 concrete bridges in Norway located close to the sea.
This thesis focuses on the long-term effects and how to ensure good quality with cathodic
protection (CP), which is a repair method that prevents further corrosion of the
reinforcement and can therefore increase the service life of a structure with several
decades. The work in this thesis has been performed using literature studies, field
investigations and laboratory analyses.
Sortlandsbrua is a cantilever concrete bridge which was built in 1975 and showed signs
of corrosion damage early in the 1980s. In 1990-1991 cathodic protection was installed
on the pillars to prevent further corrosion damage. The CP was installed using 3 different
methods, in combination with the long lifetime of the installation this makes it ideal to
investigate the bridge to study long-term effect of CP. The bridge was investigated during
the summer of 2018, 21 concrete cores were sampled from 4 different pillars to create
chloride profiles, μ-XRF scans and thin section samples. All the areas with CP was also
investigated for delamination of CP-mortar.
During the investigations there have been discovered protective and destructive
consequences of the CP over 27 years on Sortlandsbrua. Chlorides have been extracted
from the bridge concrete and ASR have been discovered at the reinforcement. Small
areas of delamination of CP-mortar were also discovered. There seem to have been
development of microcracks in the CP-mortar due to the impressed current from the CP.
Carbonated concrete seems to have affected the transportation of chlorides. The effect of
carbonated concrete on the chloride movement and different transport mechanism has
been discussed along with the consequences of the observed changes and damages.
There are suggested further investigations to supplement the findings here and give
better understanding of the findings in this thesis
Material use for winter maintenance for the 2018/19 season
Get PDFDenne rapporten er utarbeidet for å få en oversikt over ressursbruken i vinterdriften. For å se utviklingen fra år til år viser rapporten noen historiske hovedtall. Detaljer per kontrakt er basert på de vegkategorier som ble innført 1/1-2010. Mengdetallene er hentet fra entreprenørenes rapportering for hver kontrakt ut fra skjema R12, definert i driftskontraktene. Det kan være feil og mangler i datagrunnlaget. De årlige mengdene omfatter vintersesongen fra høst til vår. Det
oppgitte årstallet i diagrammene viser til siste del av sesongen. Rapporten inneholder tall for salting, sanding og brøyting.Statens vegvesen Vegdirektorate
Summary documentation 2018 : For construction projects completed in 2018
No full textRapporten inneholder byggekostnader for prosjekter som ble åpnet for trafikk i 2018.Statens vegvesen Vegdirektorate
Non- instrumented and instrumented concrete elements for long term testing : Austefjord Field station - long term testing of concrete in marine environment
No full textStatens vegvesen, Vegdirektoratet etablerte i 2017 en ny feltstasjon for langtids felteksponering av betong i marint miljø. Feltstasjonen er lokalisert ved en ferjekai i Austefjorden utenfor Bergen. Rapporten beskriver de første elementene som ble utplassert i feltstasjonen, i 2018 (Fase I) og 2019 (Fase II). Noen av elementene som ble utplassert i 2019 er instrumenterte. Instrumenteringen og datainnsamlingsopplegget for disse elementene beskrives.Statens vegvesen Vegdirektorate
Metodeutvikling av tunnelvask
Get PDFI dette oppdraget var det befart flere tunneler i Norge for å se både tradisjonelle vaskemetoder og en ny potensiell teknologi bestående av tørris. Tunnelene var Strindheimtunnel (Trondheim), Nøstvettunnelen (Akershus), Rælingstunnelen (Akershus), Stordalstunnelen (Møre og Møre og Romsdal), Dyrkorntunnelen (Møre og Romsdal), Visettunnelen (Møre og Romsdal), Blindheimstunnelen (Møre og Romsdal) og Valderøytunnelen (Møre og Romsdal). I tillegg var det tatt inn tunneldriftserfaring fra ulike regioner i Norge, dvs., Akershus, Møre og Romsdal, Oslo og Sør-Trøndelag.Statens vegvese
Verification of OON Floating Bridge Concepts BJF 2019
Get PDFThis report deals with the concepts evaluated by design group OONStatens vegvesen Vegdirektorate
Sprayed concrete with reduced carbon footprint : Field and laboratory investigation
No full textRapporten er resultat av et FoU-samarbeid med Skanska Norge AS, EntreprenørserviceAS, Unicon og BASF. I felt ble det gjort fullskala sprøyting og produksjon av prøveplater, og for sistnevnte ble energiabsorpsjonskapasitet bestemt ved Statens vegvesen sitt Sentrallaboratorium (Region Øst).
Felterfaringene (eget vedlegg) viser lovende resultater for de undersøkte sprøytebetongene som er basert på lavt sementklinkerinnhold og høyt flygeaskeinnhold. Plateprøvingen viser at sprøytebetongene kan oppnå både E700 og E1000 ved adekvat fibertype og dosering. Betongene har vesentlig fasthetsøkning fra 28 til 90 døgns alder. I samme tidsperiode øker energiabsorpsjonskapasiteten for de undersøkte betongene.Statens vegvesen Vegdirektorate
Preferred solution, K12 – Appendix O Material technology and steel in marine environment
Get PDFThe bridge design life is 100 years and this document discusses material selection and means of providing corrosion protection to limit the need for future inspections, maintenance, and replacements. The recommended solutions are summarised in the table below.
The most severe exposure conditions are in the splash zone and in this area carbon steel will be replaced by a corrosion resistant alloy, 25Cr DSS. Welding of carbon steel to 25Cr DSS is fully manageable provided properly qualified procedures and suitable materials are used.
High level cathodic protection (CP) calculations have been performed. The anode weight requirements vary dependent on the selected CP design life and extent of coating on the 25Cr DSS plates. Detailed calculations should be performed in next phase.
Corrosion allowances (CA) for the mooring chains have been evaluated based on standards and requirements included in the SVV design basis. Since the top chain is situated below the splash zone, the same CA as for the bottom chain is proposed (0.2 mm/year).
Recommendations for further work is included in a separate section at the end of the documen
K12 - Design of mooring and anchoring
Get PDFThe current report summarizes the mooring system design proposed for the recommended Bjørnafjorden floating bridge concept K12. The concept is generally the same as proposed during the concept evaluation and can easily be adapted to the other concepts that has a mooring system.Statens vegvesen Vegdirektorate
Reparasjonsmørtlers kloridmotstand : FoU-programmet Bedre bruvedlikehold 2017 – 2021
Get PDFMotstand mot kloridinntrengning er en viktig og kjent egenskap for betongens levetid. For reparasjonsmørtler er kunnskap om denne egenskapen mangelfull. Det ble derfor igangsatt et laboratorieprogram med undersøkelser av 10 kommersielle produkter. Utprøvingen ble i all hovedsak basert på metoden NS-EN 13396 Måling av kloridinntrengning.Statens vegvesen Vegdirektorate