A series of microscopic
investigations have been carried out in connection with the testing
program for the 15 concrete blocks exposed to a marine environment
at the Fehmarnbelt exposure site at Rødbyhavn. The concretes were
examined after 28 days of curing, i.e. before exposure to seawater,
and subsequently after 6 months, 2 years and 5 years of seawater
exposure. All studied thin sections and polished samples were
prepared from drilled cores.
The investigations undertaken after
6 months and 2 years of exposure also included three additional
types of concretes with binders consisting of BASIS Portland
cement, Rapid Portland cement and Rapid Portland cement + 25% fly
ash, respectively. These concretes were cast as cylinders in
connections with the production of the large concrete blocks to be
exposed at Rødbyhavn. The cylinders were exposed to seawater at the
same time as the large blocks.
Datasheets with results
from microscopy
Results from the investigations
have been collected in datasheets that contain the most important
observations from the optical microscopy. Furthermore, the
datasheets for samples examined after 6 months and 2 years of
exposure also include data obtained by scanning electron microscopy
(SEM) in combination with Energy-Dispersive X-ray (EDX)
spectroscopy. The datasheets can be downloaded here:
Fehmarn
Belt Exposure Site - Microscopy - 28 days
Fehmarn
Belt Exposure Site - Microscopy - 6 months
Fehmarn
Belt Exposure Site - Microscopy - 2 years
Fehmarn
Belt Exposure Site - Microscopy - 5 years (including comparison
with results after 6 months and 2 years)
Presentation from Nanocem
Fall Meeting in Paris, 2011
Main results from the microscopic
investigations have also been presented at the Nanocem Fall
Meeting, 25-57 November 2011 in Paris. Pictures of the exposed
concrete blocks, illustration of the sampling procedure, essential
results, etc. are included in the slides from this presentation,
which can be downloaded here:
Study of Fehmarn Belt Trial Concretes - 6 months results - Nanocem
presentation
Paper from EMABM 2013 in
Copenhagen, Denmark
Finally, results from the
microscopy investigations of the concrete blocks exposed at
Rødbyhavn Harbour have been presented in a paper prepared in
connection with the 14th Euroseminar on Microscopy Applied to
Building Materials (EMABM), Copenhagen, Denmark:
Microstructural surface deterioration of concrete exposed to
seawater - Results after 2 years exposure