With a background in natural science and geology from the University of Copenhagen, Dr. Ulla Hjorth Jakobsen has more than 25 years of experience in the field of geology, concrete petrography and material sciences and technology.

Dr. Jakobsen is highly skilled in microscopic analysis of rocks, ore, concrete, mortar, clinker and related materials using optical fluorescence microscopy, and scanning electron microscopy, and in the interpretation of textures of materials.

Dr. Jakobsen has been in charge of materials characterization and micro-structural analyses of concrete since 1991 and has analyzed more than 5000 thin sections representing all types of concrete distresses.

Dr. Jakobsen has analyzed concrete types of virtually any thinkable composition and from all parts of the world. Dr. Jakobsen has extensive experience in diagnosing concrete damaged from all sorts of mechanisms including alkali silica reaction (ASR), delayed ettringite formation (DEF), external and internal sulfate attack, acid attack, freeze-thaw action, carbonation and leaching. Furthermore, she is world renowned for using fluorescent microscopy to determine the water to cement ratio of concrete.

Dr. Jakobsen has functioned as the project manager on more than 10 major litigation cases in both the United States and Canada, as well as participated in court in one Canadian litigation.

Dr. Jakobsen has written or been the co-author on more than 20 papers dealing with concrete distress and micro-analyses of concrete.

Dr. Jakobsen has used microscopy in close collaboration with chemists and materials scientists in various types of optimization projects, for quality control and in the developing of new materials. She has worked on several projects developing new materials based on secondary raw materials. She has experience in studying the micro-structural appearance of asphalt and related products by the use of fluorescent impregnated thin sections.

Dr. Jakobsen has participated in several EU sponsored projects, including one project dealing with the development of methods for estimation of the residual alkali silica reactivity, and another project concerning the development of petrographic methods for describing the polymer distribution in bitumen.

Concrete & Related Materials:

Jakobsen, U.H., Pade, C., Thaulow, N., Brown, D., Sahu, S., Magnusson, O., De Buck, S. and De Schutter, G. 2006: Automated air void analysis of hardened concrete - a Round Robin study. Cement and Concrete Research, vol 36, 8, pp. 1444-1452

Jakobsen, U.H. and Brown, D.R. 2006: Reproducebility of w/c ratio determination from fluorescent impregnated thin sections. Cement and Concrete Research, vol. 36, 8, pp. 1567-1573.

Detwiler, R.J., Powers, L.J., Jakobsen, U.H., Campbell, D.H., Ahmed, W.U., Scrivener, K.L. and Kjellsen, K.O. (2001): A guide to preparation of concrete specimens for examination by optical and electron microscopy. Accepted by Concrete International.

Thaulow, N. and Jakobsen, U.H. 2000: Sulphate Attack as Observed by Optical and Scanning Electron Microscopy. Cement and Concrete Technology in the 2000s, Second International Symposium, 6-10 September 2000, Istanbul, Turkey

Jakobsen, U.H., Laugesen, P. and Thaulow, N. 2000: Determination of water to cement ratio in hardened concrete by optical fluorescence microscopy. ACI Symposium Volume: "Water-Cement ratio and other Durability Parameters: Techniques for determination".SP 191.

Jakobsen, U.H. and Thaulow, N. 1999: Combining optical fluorescent microscopy and scanning electron microscopy for the examination of deteriorated concrete. 7th Euroseminar on Microscopy Applied to Building Materials, Delft, pp. 191-201.

Jakobsen, U.H. 1998: Understanding the features observed in concrete using various fluorescence impregnation techniques. Proceedings of the 20th ICMA Conference on Cement Microscopy, Guadalajara, Mexico, pp. 281-301.

Palbøl, L., Jakobsen, U.H. and Thaulow, N. 1998: Petrographic Examination of Mortar Coatings - 0- to 60- year-old water pressure pipes. Concrete International, vol. 20, no. 3, pp. 47-52.

Jakobsen, U.H. and Thaulow, N. 1997: Cause of deterioration of Canadian Concrete Railroad Ties: Geology of Aggregate Source and Concrete Examination. Proc. of 6th Euroseminar of Microscopy Applied to Building Materials, June 25.-27., Reykjavik, Iceland, pp. 187-206.

Jakobsen, U.H., Johansen, V. & Thaulow, N. 1997: Optical Microscopy - A Primary Tool in Concrete Examination. Proceedings of the 19th ICMA Conference on Cement Microscopy, Illinois, USA, pp. 275-294.

Thaulow, N. and Jakobsen, U.H. 1997: Deterioration of Concrete Diagnosed by Optical Microscopy. Proc. of 6th Euroseminar of Microscopy Applied to Building Materials, June 25.-27., Reykjavik, Iceland, pp. 282-296.

Thaulow, N. and Jakobsen, U.H: 1997: The Diagnosis of Chemical Deterioration of Concrete by Optical Microscopy. In: Scrivener, Young (eds.), Mechanism of Chemical Degradation of Cement-based Systems, E&FN Spon, pp. 3-13.

Thaulow, N., Jakobsen, U.H. and Johansen, V. 1997: What causes Delayed Ettringite Formation? In: Scrivener, Young (eds.), Mechanism of Chemical Degradation of Cement-based Systems, E&FN Spon, pp. 219-226.

Pade, C., Jakobsen, U.H. and Johansen, V. 1997: Evolution of Expansion, Weight gain, Microstructure and Microchemistry of DEF Affected Mortar". 13. Internationale Baustofftagung Weimar Bundesrepublik Deutschland. Bausil. Tagungsbericht - Band 1 pp. 1-0521.

Thaulow, N., Jakobsen, U.H & Clark, B. 1996: Composition of Alkali Silica Gel and Ettringite in Concrete Railroad Ties: SEM, EDX and X-ray Diffraction Analyses. Cement & Concrete Research, vol. 26, no. 2, pp. 309-318.

Jakobsen, U.H., Johansen, V. & Thaulow, N. 1995: Estimating the Capillary Porosity of Cement Paste by Fluorescence Microscopy and Image Analyses. Mat. Res. Soc. Symposium Proceedings vol. 370, pp. 227-236.

Johansen, V. & Jakobsen, U.H. 1993: An Examination of Clinkers with Light Colored cores. ICMA, Fifteenth International Conference on Cement Microscopy, Dallas, Texas, pp. 127-142.

Johansen, V., Thaulow, N., Jakobsen, U.H. & Palbøl, L. 1993: Heat Cured Induced Expansion. 3rd Beijing International Symposium on Cement and Concrete, China.

Jakobsen, U.H., Thaulow, N. & Johansen, V. 1992: Analyses of Sodium- and Potassium-rich Droplets observed on the Surface of Alkali-silica Reactive Aggregates and on gel in Polished Thin Sections. Cement & Concrete Research, vol. 22, pp. 1148-1160.

Selected Industrial Reports:

Jakobsen, U.H. & Thaulow, N. Investigation of the cause of failure of a ruptured 36" lined cylinder pipe, Cleveland, Ohio. Company report, 1998

Jakobsen, U.H. and Pade, C., "Examination of Hot Pressed Samples from XXXXXX", company report, Italy, March 1998, RAMBOLL No. 971319. 

Jakobsen, U.H. Examination of standards for w/c determination, USA. Company report, 1998

Jakobsen, U.H. Petrographic analysis of concrete samples from Piezometric Tower, Cordenons, Italy. Company report, 1997

Jakobsen, U.H. & Thaulow, N. Examination of concrete foundation, Canada. Company report, 1997

Jakobsen. U.H. & Thaulow, N. Visual inspection of 23 houses, Quebec, Canada. Company report, 1997

Jakobsen, U.H. & Thaulow, N. Petrographic analysis of 4 cores from precast concrete beams, USA. Company report, 1996

Jakobsen, U.H. & Thaulow, N. Petrographic analysis of 6 cores from concrete panels in parking garage, USA. Company report, 1996

Jakobsen, U.H. Examination of concrete core Matsesta Bridge M27, KM 293+15, Russia, Company report, 1996

Jakobsen, U.H. Microscopic analysis of concrete from silo complex, Nicosia. Company report, 1996

Jakobsen, U.H. Microscopic apperance af CACC, France. Company report, 1996

Jakobsen, U.H. & Thaulow, N. Investigation of the cause of distress of concrete panels, Continuum Parking Garage, USA. Company report, 1996

Jakobsen, U.H. & Thaulow, N. Petrographic examination and SEM-analysis of concrete pavers, USA. Company report 1995.

Jakobsen, U.H. Thin section analysis of 2 concrete samples from Dubai. Company report, 1995

Jakobsen, U.H. Examination of materials for concrete, Tanzania. Company report, 1995

Jakobsen, U.H. Investigation of hollow microspheres, Germany. Company report, 1994

Jakobsen, U.H. & Thaulow, N. Eliminating or Minimizing Alkali Silica Reactivity, Task 3, Subtask 3.2. Brite-Euram Report, 1993

Jakobsen, U.H. Examination of Epoxy-injected concrete cores, DK. Company report, 1993

Jakobsen, U.H. & Thaulow, N. Petrographic analyses of concrete poles, Canada. Company report, 1993

Jakobsen, U.H. X-ray diffraction analyses of ettringite from two concrete samples, USA. Company report, 1992

Jakobsen, U.H. Analysis of the pattern of ettringite-filled cracks, USA. Company report, 1992

Jakobsen, U.H. & Thaulow, N. Estimation of concrete composition, USA. Company report, 1992

Jakobsen, U.H. Estimation of pyrite in aggregates, USA. Company report, 1992

Jakobsen, U.H. Microprobe analyses of ettringite from 2 ties, USA. Company report, 1992

Jakobsen, U.H., Thaulow, N. & Johansen, V. SEM-EDX analyses of alkali-silica gel and ettringite in thin sections, USA. Company report, 1992

Jakobsen, U.H. & Thaulow, N. Microscopic examination of 3 freeze-thaw tested samples, USA. Company report, 1992

Jakobsen, U.H. & Thaulow, N. Measurement of gaps around aggregate particles, USA. Company report, 1992

Jakobsen, U.H. A study into the behaviour of olivine when used as aggregate in concrete, DK. Company report, 1992

Jakobsen, U.H. & Kerrich, D. Examination of Concrete Aggregate from the Lone Star Quarry, USA. Company report, 1991

Jakobsen, U.H. & Thaulow, N. Thin Section Examination of Concrete Tie Samples, USA. Company report, 1991

Jakobsen, U.H. Microscopic examination of two high performance mortar samples, DK. Company report, 1991

Jakobsen, U.H. & Thaulow, N. Microscopic Examination of twelve German Tie Samples, Germany. Company report, 1991

Jakobsen, U.H. & Andersen, P.J. Summary of the petrographic examination of 7 prestressed pipe mortars or concrete coatings, Dallas. Company report, 1991

Jakobsen, U.H. & Andersen, P.J. Studies of the current mix design of concrete for Pont de Normandie, Activity 3, USA. Company report, 1991

Jakobsen, U.H. Examination of the aggregates in the Francon, Quarry: A Geological Review, Canada. Company report, 1991

Jakobsen, U.H. Macro and microscopic examination of Francon concrete ties, Canada. Company report, 1991

Jakobsen, U.H. & Thaulow, N. Examination of four Finnish Concrete Ties, Finland. Company report, 1991

Andersen, P.J. and Jakobsen, U.H. "Petrographic Analysis of Pre-Stressed Concrete Pipe Mortar", Reports 1-8, company reports, U.S.A., May 1991, GMIC No. 910409.

Andersen, P. J. and Jakobsen, U. H. "Analysis of Pre-stressed Concrete Pipe Mortar", company report, U.S.A., May 1991, GMIC No. 910409.

Thesis’s:

Jakobsen, U.H. 1993: Geochemistry of Lower Palaeozoic Sedimentary Rocks of North Greenland. Ph.D. Thesis, Geological Institute, University of Copenhagen. Volume I 162 pages, Appendix 82 pages.

Jakobsen, U.H. 1987: An Ore Geological and Geochemical Investigation of a Zn-Ba Mineralised Area in Freuchen Land, Central North Greenland (in Danish). M.Sc. Thesis, Geological Institute, University of Copenhagen. 168 pages.

Geological Relevant Publications:

Jakobsen, U.H. & Ohmoto, H. 1993: Bitumen Associated with Precipitation of Sulfides in a Carbonate Hosted Zn-Ba Vein Mineralization, North Greenland. In: Parnell, J., Kucha, H. & Lundais, H. (eds): Bitumen in Ore Deposits. Spec. Publ. No. 9 Soc. Geol. Appl. Min. Deposits., Springer Verlag, pp. 399-414.

Jakobsen, U.H. 1990: A Hydrated Barium Silicate in Unmetamorphosed Sedimentary Rocks of central North Greenland. Min. Mag. v. 54, pp. 81-89.

Jakobsen, U.H. 1989: Geochemical Stream Sediment and Overburden Surveys of a Zinc- and Barium-Mineralized Area, Freuchen Land, central North Greenland. Journ. of Geochem. Explor. v. 31, pp. 117-134.

Jakobsen, U.H. 1989: Hydrated Iron Sulphate Occurrences at Navarana Fjord, Central North Greenland. Bull. Geol. Soc. Denmark, v. 37, pp. 175-180.

Jakobsen, U.H. & Stendal, H. 1987: Geochemical Exploration in central and western North Greenland. Report Greenland Geological Survey 133, pp.113-121.

Jakobsen, U.H. & Steenfelt, A. 1985: Zinc Mineralization at Navarana Fjord, central North Greenland. Report Greenland Geological Survey 126, pp. 105-109.

Abstracts, Posters and Popular Articles:

Jakobsen, U.H. 1989: A short Review on the geology of North Greenland. The 21st Penn State Geoscience Graduate Student Colloquium. Abstract, Pennsylvania State University.

Jakobsen, U.H. & Stendal, H. 1989: Follow-up studies of Anomalous Zinc and Barium Areas in central and western North Greenland. Abstract, XIII Intern. Geochem. Explor. Symposium, Rio 1989, pp. 107-108.

Jakobsen, U.H. & Ohmoto, H. 1989: The environment of organic accumulation in open/closed cycles of the North Greenland Basin: Evidence from Sulfur Isotopes and Elemental Geochemistry. GSA Abstracts with Programs, vol. 21, no. 6.

Jakobsen, U.H. 1988: Geochemical Exploration in a Zn and Ba Mineralized Area, North Greenland. Poster, Nordic Geological Winter Meeting, Copenhagen.

Jakobsen, U.H. 1987: An Ore Geological and Geochemical Investigation of a Zn-Ba Mineralized Area in Freuchen Land, Central North Greenland (in Danish). Abstract, Student Symposium, Geological Institute, University of Copenhagen.

Steenfelt, A. & Jakobsen, U.H. 1986: Ore in North Greenland (in Danish). VARV 1986/1, pp. 18-23.

Jakobsen, U.H. 1985: A Zink and a Sulphate Mineralization in the North-Western Part of Freuchen Land, Central North Greenland. Abstract, Student Symposium, The Geological Field Club of Lund, Sweden.

Reports & Education etc.:

Hamann, N. E. & Jakobsen, U. H. 1990: Field notes and small tips. Summer course in Geology for Geography Students, Mors. 11 pages.

Pratt, A. & Jakobsen, U.H. 1988: An introduction to the use of chemistry and isotopes in ore geology (in Danish). Notes for Course in Geology 6A. Geological Institute, University of Copenhagen. 54 pages.

Jakobsen, U.H. 1987: Field report: Geochemical Prospecting, Godthåbs Fjord, 1986 (in Danish). Intern Rapp., GGU, 10 pages.

Jakobsen, U.H. & Stendal, H. 1985: Regional Geochemical exploration program and detailed follow-up surveys in central North Greenland 1985. Express Report, GGU, 7 pages.

Jakobsen, U.H. 1984: Preliminary ore microscopic examination of heavy mineral samples from the central North Greenland, 1984 (in Danish). Intern Rapp. GGU, 15 pages.

Jakobsen, U.H. 1984: Deposits at Navarana Fjord. Express Report, GGU, 1 page.