Om Materialprøvningens Udvikling i Norden
Og om Statsprøveanstaltens Virksomhed
År: 1909
Sted: Kjøbenhavn
Sider: 185
UDK: 6201(09)
Emne: Trykt hos J. Jørgensen & Co. (M. A. Hannover)
On the development of testing of materials in the north and on the work of the danish states testing laboratory in Copenhagen (english translation)
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1897 as general (see fig. 2, page 10), with the drawing up of a pro-
posal of enlarging the existing maritime fortifications of Copen-
hagen the captain recommenced the earlier series of experiments
on an enlarged scale and introduced especially the Portland-cement
into the experiments.
From the 15th of April 1858 tensile tests with mortar-bri-
quettes were also commenced.
By these preparatory experiments the attention was called to
the good qualities of the Portland-cement and as, besides, a cer-
tain fear arose that the pile-worms should too rapidly destroy
the wood-construction in the foundation of the maritime forts
the quay-wall in the harbour of fort »Prøvesten« was made as a
wall of blocks founded of Portland-cement-concrete with broken
stones of granite.
Having made sufficient experiments they had from the very
beginning succeeded in making the concrete in the proper way
both respecting proportions and mixing and ramming of the
mixture; and therefore the blocks showed such a strength during
the transport and the placing that captain Ernst proposed to the
Engineer Corps to try how far concrete would show greater power
of resistance against cannonade than the masonry of bricks in
lime-cement-mortar or of cleaved stones of granite in cement-
mortar, which were meant to be used at the building of the fort.
For that reason there was made shooting-tests on masonry of
the above-mentioned kinds, and the concrete proved to possess a
far greater elasticity and cohesive power than the other kinds of
masonry (Description of the experiments are to be found in »Over-
sigt over Artilleriets Forsøg II«, 1866). It was therefore resolved
to make the forts entirely of concrete; and this material was
afterwards used in the other maritime forts and in the pro-
visory redoubts at Dybbøl — although to less extent, ol regard to
the expenses.
In spite of this method being made known to foreign conn
Iries (see for instance the fifty years’ jubilee-treatise of the Port-
land-cement-factory of Stettin) it was adopted nowhere else, before
the development of the artillery about 20 years after forced the
countries to leave the earlier masonry-materials and adopt the
Porlland-cement-concrete as the chief-material in the military-
engineering.
By the building of the new sea-forts and the strengthening