Improvements in or connected with the Construction of Fire-proof Concrete Ceilings and Floors.
Year: 1898

page_text: Date of Application, 31st Dec., 1898-Accepted, 11th Feb.,
1898
COMPLETE SPECIFICATION.
Improvements in or connected with the Construction of Fire-proof
Concrete Ceilings and Floors.
We, JOHANN FRANZ KLEINE, Architect, Erbach on the Rhine, and ALFRED
STAFF, Government Architect, of Lutzowufer 5A, Berlin, W, both in the German
Empne, do hereby declare the nature of this invention, and in what manner the
same 18 to be performed, to be particularly described and ascertained in and by
the following statement:-
This invention relates to an improved construction or method of making fire-
proof concrete ceilings and floors which can advantageously be used for the most
various loads and also for comparatively large spans and continuous floors or
ceilings
Hitherto in constructing concrete ceilings for comparatively large spans the iron
bars to be inserted into them were mostly bent to the elastic or catenary curve,
or straight iron insertions were embedded solely in the lower part of the section of
the ceiling
Such ceilings in order to carry the load safely requned to be thick
and consequently were comparatively expensive to make They also were safely
applicable only for uniformly distributed loads and in other cases were deficient
in the necessary safety, for instance under one-sided loads and for the frequently
occurring continuous ceilings or floors
These defects are obviated by our improved method of constauction and ceilings
made according to the same are free from them Thus ceilings are obtained
which with less thickness than hitherto usual offer complete safety for the most
Talous cases of loading, and in which the problem of usefully employing in a
combination of two materials the principal qualities of each in the most advan-
tageous and economical manner is practically solved.
Concrete ceilings are made according to our improved method of construction
in the following manner:
At the commencement non bars are bedded in the concrete near to the under-
Bide of the ceiling and in the middle part of the same or of the span, and then
after concrete has been further filled in, other iron bars are embedded near to the
upper side of the ceiling at the girders or wall supporting the two sides of the
ceiling, which bars extend into the neighbouring concrete slabs or are bound into
the brickwork of the outer walls. A special connection of these inserted iron
bais with each other is advantageous in some cases, but is not necessary and it
is quite sufficient if the ends of the upper and lower iron insertions overlap each
other for about one-fifth of the span or distance between the ceiling Joists If a
very high degree of safety 18 desired the iron bars embedded in the underside of
the concrete ceiling may be extended to the Joists or bearings at either side,
especially in order to prevent the injurious pealing off of the concrete under the
action of heat, and may be used for the fireproof Jacketting of girders and the
like.
The iron bars to be embedded are not limited to special profiles, any known
suitable section of bars may be employed Preferably we use bars having pro-

page_text: jections and recesses for the better adhesion of the concrete The distance from
each other of the barn to be embedded depends on the span and the load.
The method herein before described permits the construction of safe concrete
ceilings or floors of large span, a rational utilisation of the principal qualities
of the materiale employed, a hitherto unattained capacity of supporting,loads
under the most various cases of distribution, and cheap execution of the work
in consequence of its simplicity
The drawing appended hereunto shows as a specimen one of the many ways
in which our invention may be carried out, a denoting the bars inserted at ог
near to the underside and the bars embedded near to the upper side of the ceil-
ing, and c the concrete On the left of the gnder d 18 shewn how the bar a
may be used for the fire proof embedding of a girder or joist
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim 18.―
1. The method of constructing concrete ceilings or floors by first placing iron
bars near to the underside of the ceiling or floor, then filling in concrete and
embedding other iron bars near to the upper surface of the ceiling or floor in
such a manner, that the free ends of the upper bars overlap the ends of the lower
bars, substantially as hereinbefore described and illustrated by the drawings.
2 In ceilings or floors formed of concrete with iron insertions, the arrangement
of iron bars extending over the middle part or entire width of the span near to
the underside of the ceiling or floor and other iron bars embedded in the concrete
near to the upperside of the ceiling or floor and overlapping the ends of the lower
bars and built into the outer walls or extending across the joists, substantially as
hereinbefore described and illustrated by the drawings
Dated the 30th day of December 1898
RJ URQUHART, CE.,
Chartered Patent Agent, 57, Barton Arcade, Manchester.