Improved System of Flooring of Strengthened Beton or Concrete.
Year: 1897

page_text: Date of Application, 20th Dec., 1897-Accepted, 16th Apr., 1898
COMPLETE SPECIFICATION.
Improved System of Flooring of Strengthened Beton or Concrete.
I, FRANÇOIS HENNEBIQUE, of 54, Boulevard Saint Michel, Paris, in the Republic
of France, Engineer, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained in
and by the following statement:-
Floors of strengthened concrete have hitherto been made by moulding on the
spot the flooring as a whole either as regards the plane horizontal part forming the
flooring proper and corresponding to the joists, lath work, and ceiling plastering
or the beams forming the girders which rest on the walls and the support columns.
For this object a false flooring is constructed on the surface to be covered, the
various parts of which false flooring are arranged to serve as a mould respectively
for the lath work and ceiling joists of strengthened cement or beton. It is only
removed from the mould when the ceiling is completely finished.
In order to facilitate the construction and fixing of floorings of strengthened
beton and to render such operations more rapid and economical, I make the major
part of the floor (all the horizontal part, that is, the flooring proper and the ceiling)
by means of light slabs easily handled and conveyed moulded in advance by the
ordinary processes for moulding strengthened beton. The iron forming the
strengthening part or core of these slabs projects to the desired extent on the same
and these projections are bedded in a suitable manner in the beton of the beams
or joists which are moulded on the spot and they thus form a connection between
the slabs and the beams, the latter in turn fastening the slabs together and the
Various types of the floorings con-
whole forming an undeformable monolith.
structed on these principles are shown in the accompanying drawings.
The flooring shown in detail in Figures 1-13 is formed by a first series of lower
slabs, A of strengthened beton forming the ceiling and a second series of upper
slabs B forming the flooring proper. The slabs or plates moulded beforehand
have a metallic core or strengthening part, the projections of which are bedded in
the beton and suitably connected to the cores or strengthenings of the joists C
moulded on the spot.
Figures 1, 2 and 3 show a slab A respectively in plan view, side elevation and
These slabs moulded according to the ordinary known process
transverse section.
contain a certain number of iron ribs a which are incorporated longitudinally
therein and the ends of which project. Each projection of these iron parts which is
turned in order to be bedded in a joist or beam is in length approximately equal
to the height of said joist.
up
Figures 4, 5 and 6 represent an upper slab B respectively in plan view,
longitudinal section and transverse section. The core of these previously moulded
slabs is formed of a certain number of transverse pieces of iron 61 completely buried
in beton and by a series of longitudinal ribs or pieces of iron b, the projecting ends
of which penetrate horizontally into the beton of a joist.
:

page_text: In order to form a flooring by means of the prepared slabs A. and B the procedure
is as follows:-
Madriers E are arranged at intervals carried by walls F and if necessary
provisional supports G. These madriers are placed at points where the lower slabs
abut, their distance from centre to centre being thus slightly superior to the length
of a slab A. The ends of the slabs are placed on the madrier E, as shown in
Figure 7, leaving between them the width of the base of the girder C. The
projecting irons a are slightly turned up.
Figure 8 represents the second stage of the operation in which the interval
between the slabs is filled with beton forming thus the lower base of the girder C,
whilst bars D and D which form the tension chord of the girders are arranged
between the iron bars a which are turned quite upwards. The projections of the
bars a thus form stirrups which in the girder connect the chord of tension
with the chord of compression. It is evident that the bars D and D¹ may also
be carried by a series of independent stirrups such as e, Figure 22...
As shown in Figure 9, planks H are placed longitudinally and edgewise and are
held in position and at the desired distance apart by means of boards or cramps K
(Figure 22). They serve for moulding the body of the joist or girder C which
they limit laterally. The interval between the planks H is filled with beton up
to the level N. When the béton has set, the planks are withdrawn and the
slabs B are placed as shown in Figure 10 on the girder body C thus formed, which
slabs are intercrossed by the ends of the iron bars b. The intervals between the
ends of the slabs B are filled with beton and the heads of the joists C. are thus
formed.
Figure 11 shows the whole when completed, in longitudinal section through the
slabs A and B and in transverse section of a girder C. The whole A B C that is
to say the entire flooring forms as may easily be seen, a perfectly un-deformable
monolith. A floor is thus formed with interposed air spaces such as is shown on
a reduced scale in transverse vertical section through the slabs in Figure 12 and
in plan view in Figure 13. A portion of this plan view.is. a section on: the
line xy of Figure 11 and shows the lower slabs A, the bars and rods of iron
which form the frame work or core are drawn in broken lines. It will be noted
that the girders C are formed according to the method described in my other Patent
of this date No. 30143. They comprise in their lower part a tension chord formed
of a first horizontal bar D and a second horizontal bar D', Figure 12, in its central
part and raised at its two ends in order to cross the breaking strain.
In the upper slabs B it would be easy to incorporate if desired a mosaic pave-
ment. The upper surface of the floor may be polished and lends itself also to
various decorative effects. In order to allow of the flooring being still more
quickly laid, I can dispense with the planks H by moulding slabs A with a raised
edge A Figures 14 to 18; and prolonging the beak B¹ of the slabs B so that the
beak will rest directly onto the projecting surface A¹. A simple examination of
Figures 14 to 17 shows the successive stages of the placing of the slabs' A and B
and the moulding of the joists C.
[
Figure 18 is a vertical section of the whole flooring. Figures 19 to 26 represent
a flooring with simple ceiling constructed on the same principles. The slabs B
may be formed as shown in detail in Figures 19, 20 and 21. Each slab is provided
on one of its longitudinal sides with a set-off or ridge I on which the opposite side
of the next slab is placed. The metallic core of each slab is formed of a series of
longitudinal iron bars 6 and 62, the projecting ends of which will be incorporated
in the beton of the joists C. These iron rods are connected by stirrups of flat
straight iron or round iron e¹, Figure 21. In the flat part of the slab transverse
iron bars b¹ are completely encased.
In order to fix the flooring in place a mould formed of the madrier E and planks H
are arranged for each joist C, and held by clamps K. After some beton has been
poured into the bottom of the mould, bars D D¹ which form the tension chords of

page_text: the joists are inserted or arranged and the straight independent stirrup pieces e
which connect them are then placed in position.
Figures 23, 24 and 25 illustrate sufficiently the successive stages which allow of
the flooring being completed, the whole of which is shown in vertical section in
Figure 26.
It is needless to state that the slabs A. and B and the joists C need not necessarily
have the form which I have given them as an example in the accompanying
drawings.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
a
are
1. The construction in general of floorings of beton strengthened with iron or the
like by means of slabs, forming the ceiling and floor, said slabs being moulded in
advance or beforehand at the work-shop, and having their cores projecting in such
way as to be bedded in the beton of the joists (C) which
moulded on the spot, the said joists being thus connected in a perfect
manner to the slabs which they connect one to the other in such a way that the
whole floor forms a non-deformable monolith, substantially as hereinbefore set
forth.
1
2. In a system of flooring of strengthened beton constructed by means of slabs
moulded beforehand, a system of ceiling slabs (A) provided with lateral pro-
jections (A) serving as support for beaks (B¹) formed on the flooring slabs (B)
of the joists, the said projections (A) and beaks (B1) being thus adapted to be
utilized as lateral walls for moulding the joists (C), substantially as hereinbefore
described.
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1007
W. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Agents for the Applicant.