NBTL intends to convey knowledge and experience to the construction industry in Norway and abroad, to the benefit of all. On this page you will find a selection of papers in Norwegian and English

see also  literature list 

read NBTL's information materials

read about Alkali Silica Reaction

read about petrographic analysis

read about in-situ measurement of RH, expansion of cracks and effect of mono silanes

read about the condition of Norwegian concrete dams

read about damages caused by slip forming and damages in repairs, dam Langevann

NBTL' information material

NBTL's first newsletter can be downloaded here. More newsletters are planned to be published.     Newsletter 1  New: Newsletter October 2003  (in Norwegian)

NBTL's poster exhibition on the Norwegian "concrete day" 2002, Rica Park Hotel Sandefjord.   Poster exhibition

Paper published  in the Journal "Bygge industrien" 19. Desember 2003: 

Paper by Viggo Jensen which aim to be an introduction to debate about the coming requirements and test methods according to ASR in Norway. The Norwegian Concrete Society committee NB 21 have made the coming Norwegian standard which will be submitted to public hearing in the spring 2004. Read the paper and comments to the paper. Also read comments to comments (all in Norwegian)

Alkali Silica Reaction (ASR)

Free!  Viggo Jensen's doctor thesis which have documented the occurence of Alkali Silica Reaction in Norway can be purchased free of charge on conditions to pay mailing costs your self (as long books are in stock)

Viggo Jensen 1993: "Alkali-Aggregate Reaction in Southern Norway", Doctor Technicae thesis, Division of geology and mineral resources engineering, The Norwegian Institute of Technology, University of Trondheim, NTH-Trykk, 262pp + 9 Appendices

Executive summary and content

Contact Viggo Jensen in case you want a thesis.                 E-mail:   viggo.jensen@nbtl.no

 

Miscellaneous papers

The following papers deals with damages caused by ASR on Elgeseter bridge in Trondheim and railway sleepers (in Norwegian). Results from a parallel testing of same Norwegian reactive aggregates performed in  Norway and Canada documented that the Canadian Concrete Prism Method is reliable also for Norwegain aggregates as long the test is carried out according to the standard method. Same paper also gives a correlation factor between Rilem prism sizes (used in Norway) and ASTM prism size (used in Northern America). The paper "Alkalireaksjoner ikke i mål" is  comments to the research project  "Normin 2000" (in Norwegian).

Viggo Jensen 2003: “Elgeseter bridge in Trondheim damaged by alkali silica reaction: microscopy, expansion and relative humidity measurements, treatment with mono silanes and repair”, Proceedings of the 9th Euroseminar Applied to Buildings Materials, 9.- 12 September 2003, Trondheim Norway. Extended abstract

Viggo Jensen & Benoit Fournier 2000: “Influence of Different procedures on Accelerated Mortar Bar and Concrete Prism Tests: Assessment of Seven Norwegian Alkali-Reactive Aggregates”. Proceeding of the 11th International Conference on Alkali-Aggregate Reaction in Concrete, Quebec, Canada, 11-16 June 2000, 10pp

Viggo Jensen, Halstein Gåsemyr og Karle Jensvik 2000: "Alkalireaksjoner i sviller", Betongindustrien nr 2, 2000.

Viggo Jensen 1999: “Alkalireaksjoner ikke i mål ?”. Betongindustrien, nr 2, 31 årgang side 32-34

Gemini nr 1 1997:  "Alkalireaksjon skader bruer og dammer"

The following papers gives information's on Rilems Petrographic method (AAR-1) which will be published in 2003. A similar method have been used in Norway since 1993. Viggo Jensen was chairman for the international working group who prepared the method  and secured the coexcistence between the Norwegian method and Rilems method. The Norwegian method is developed  and based on research by Viggo Jensen.

Viggo Jensen & Ted Sibbick 2001: “Rilem petrographic method: Practical use and comparison with other petrographic methods in use”, Proceeding of the 8th Euroseminar on Microscopy Applied to Building Materials, 4 – 7  September, Athens, Greece, 8pp

Viggo Jensen  & Gabriel Lorenzi. 1999: “Rilem petrographic Method for Analysis of Alkali Reactive Concrete Aggregates”. Proceeding of the 7th Euroseminar on Microscopy Applied to Building Materials, Delft, The Nederlands, June 29-July 2, p143-p153

Since 1995, an in-situ system for measurement of relative humidity and expansion of cracks, have been in use on several concrete structures in Norway. Relative humidity is measured by use of wooden sticks drilled  into the concrete and in equilibrium with the concrete's humidity. Expansion of cracks is measured on 3 measurements rosettes with a Demec gauge.  Measurements is still performed on the same structures (and several more) and have given inportant information on the development of damages due to ASR and the significance of micro climate. The wooden stick method is very reliable and durable because the same wooden sticks mounted in the structures in 1995 still is reliable and in use. Tests with several types of coatings and impregnations with mono silanes have given very promising results and have in several occasions decreased the concretes relative humidity to below 80%. This research was started up by Viggo Jensens in his postdoctoral project financed by the Norwegian Research Council..

Viggo Jensen 2003: "Relative Humidity Measured by Wooden Stick Method in Concrete Structures: Long Term Measurements and Reduction of Humidity by Surface Treatment", 6th Int. Conf. on Durability of Concrete, ACI/CANMET, Thessaloniki, Greece 2003 (modified paper)

Viggo Jensen 2002: “Relative Humidity measured by the wooden stick method in Norwegian concrete Structures with and without surface protection”, XVIII Symposium on Nordic Concrete Research, Helsingør 12-14 June 2002, Denmark

Viggo Jensen 2001: “Forskningsprosjektet: Sikkerhet av damkonstruksjoner”, Norsk betongdag 2001 – NTNU-SINTEF informasjonsdag 2001, Sintef rapport STF 22 A01616, side 70-78

Viggo Jensen 2000: “In-situ Measurement of Relative Humidity and Expansion of Cracks in Structures Damaged by AAR”. Proceeding  of the 11th International Conference on Alkali-Aggregate Reaction in Concrete, Quebec, Canada, 11-16 June 2000, 10pp

A national survey of the condition, damages, repair and safety of Norwegian concrete dams was part of Viggo Jensen's postdoctoral project. The survey gave very surprising results. Read more in the following papers and from  the daily newspapers.

Viggo Jensen 2002: ” Resultater fra spørreundersøkelse vedr. betongdammers tilstand: Uddrag fra SINTEF rapport STF22 A01603”, EBL’s Vassdragsteknisk forum, Vårseminar, Oslo, 3 sider

Viggo Jensen 2001: ”Survey about damage, Repair and Safety of Norwegian Concrete Dams”, ICOLD European Symposium, Geiranger, Norway 25-27 June 2001, 8pp

Gemini nr 1 2002   (in Norwegian)    Newspapers  (in Norwegian)

Norwegian concrete dams need repairs that will cost billions of kroner (from webb page)

 
Dam Langevann was the largest concrete plate dam in Norway when it was constructed in the period 1965 - 1967.  The dam is located in an inaccessible mountain area and slip forming was used for the concrete work  of dam plates. In 1996 and due to a very low water level in the  dam many longitudinal cracks and damages were observed on most of the dam plates.  These were repaired,  but already the next year several of the repairs were damages, some with a smouldering consistence.  Read more in the following papers (in Norwegian).
 

Viggo Jensen 2002: “Dam Langevann. Del 1: Skader forårsaket av glidestøp og utluding”. Betongindustrien, nr 1, 34 årgang

Viggo Jensen & Gerhard Kurszus 2002:Dam Langevann. Del 2: Reparasjoner av damplater og skader i reparasjoner”  Byggeindustrien nettsider 28 november 2002, http://www.byggeindustrien.no/news/newsshow.asp?NewsID=3753

 
Betongindustrien 2003/2004. Kommentarer til kommentaren  Artikkelen publisert i Byggeindustrien - nettsider den 19.desember 2003 er tenkt som et diskusjonsopplegg til kommende nye regler vedr. alkalireaksjon i Norge og vil ikke bli ytterligere kommentert av NBTL. Det nye regelverk utarbeides av  en komité under norsk betongforening, NB 21 komiteen, og forslaget vil komme til høring våren 2004 og vil bli norsk standard på dette område. Det skal å understrekes at problemområdet alkalireaksjon er behandlet på en seriøs måte av alle aktører i Norge og det er ikke tanken å så tvil om dette. Derimot er det viktig å understreke at moderne betonger inneholder reduserte mengder alkalier sammenlignet med tidligere betonger. Moderne betonger er dermed "mindre kjemisk aggressiv" overfor bergarter, noe som ikke fanges opp av en petrografisk analyse. Når en allikevel skal innføre en betongprismemetode til regelverket så hvorfor ikke en internasjonal metode som Canadisk betongprismemetode CSA A23.2-14A:2000  hvor metodens usikkerheter er kjent og grenseverdier akseptert i hele verden? Eller Rilem metode AAR-3 som vil bli kommende europeisk standard i fm. neste generasjons EU-standarder om ca 5 år? Det er omvendt logikk å påstå at Norsk betongprismemetode er veldokumentert og at det vil "føre til stor usikkerhet og forvirring å innføre nye metoder og grenser over natten". Norsk betongprismemetode er en modifikasjon av den  canadisk betongprismemetode hvor effekten av større prismer ikke er kjent, noe som kan ha betydning for ekspansjonsresultatet; for ikke å nevne grenseverdier, men dette er ikke undersøkt. Videre er Norsk betongprismemetode kun testet på et begrenset antall norske bergarter - så vidt NBTL har kjennskap til. Norsk betongprismemetode er unødvendig dyr å utføre og spørsmålet er om betong- og tilslagsbransjen vil betale denne prisen for å få en korrekt klassifisering av tilslaget sitt.

Syv norske alkali reaktive bergarter ble parallell testet med en tidligere versjon av "Norsk betongprismemetode" og  original Canadisk betongprismemetode i Canada. Resultatene viste at den tidligere versjon av norsk betongprismemetode gav signifikant lave verdier og at original Canadisk betongprismemetode tilsynelatende gav riktig resultat, selv for sandstein. Les artikkelen av Viggo Jensen og Benoit Fournier (Engelsk).

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