Improvements in and relating to Fire Proof Buildings,
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in and relating to Fire Proof Buildings,
I, ALPHONSE DE MAN, of 223, Park Street, in the City of Detroit, County
of Wayne, and State of Michigan, United States of America, Manufacturer, do
hereby declare the nature of this invention to be as follows:
-
My invention relates to fire proof building construction and more particularly
to the construction of the floors and ceilings and the means employed for insulating
the columns and other metallic members to protect them from heat in case of
a fire.
The floor construction which I employ comprises composite spans the body
portion of which is formed of artificial stone (preferably the ordinary concrete)
and is strengthened by metallic members embedded in said body while it is in
a plastic state and adapted to furnish to the completed span the necessary
tensile strength.
The novel features of this construction are first the character of the metallic
strengthening members employed which are formed of flat thin bars, preferably
steel or iron, provided at intervals with twists or lateral deflections which form
holding shoulders or anchors and prevent slipping of the bar through the body.
These bars when arranged on edge, side by side, leave a greater space between for
the artificial stone body than if bars of equal strength but of round or square cross
section were used.
A second feature is the peculiar form and arrangement of these bars which are
so disposed as to furnish the requisite tensile strength to the span with a minimum
amount of metal. For accomplishing this, I employ horizontal tension members
formed of the above described bars, and located below the neutral line in the body
of the span. These bars may if desired be placed under tension. Also double
inclined members extending from the upper part of the body at their ends
downward toward the central portion of the span.
A farther feature of the floor construction is the construction of composite beams
or guides comprising metallic tension members as above described which are
arranged so as to form in connection with the artificial stone body, a trussed
beam, and in connection with the floor spans forming a monolith floor.
The ceiling construction also comprises a body of artificial stone which is
strengthened and supported, beneath the floor, by the above described metallic
strengthening members which are preferably of the U-shaped form with the ends
resting upon the floor beams.
The columns and other exposed metallic parts are thoroughly insulated or pro-
tected from heat by a covering which comprises a wrapping of wire netting
spaced from said metallic member by metallic ribs or bars extending longitudinally

page_text: thereof and spaced and secured in position by metallic hoops
said metallic member.
or bands surrounding
I, ALPHONSE DE MAN, of 223, Park Street, in the City of Detroit, and
State of Michigan, United States of America, Manufacturer, 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:-
My invention relates to the construction of composite slabs or spans especially
designed for fire proof floor construction and comprising a body of artificial stone,
having metallic strengthening members embedded therein.
The invention consists first in the peculiar construction of metallic members
employed for strengthening the slab, and further in the peculiar construction of a
composite slab or floor span, in which these metallic members are employed;
further in a floor and ceiling construction comprising said slabs or spans; further
in the means employed for insulating the metallic columns, and further in
the peculiar construction, arrangement and combination of parts as more fully
hereinafter described and claimed:
In the drawings, Fig. 1 is a perspective view of the metallic strengthening
member.
Figs. 2 and 3 are views of modifications thereof.
Fig. 4 is a plan showing the manner of forming the twists in said strengthening
member.
Fig. 5 is a plan view of a number of said strengthening members as arranged in
position to receive the artificial stone body.
Fig. 6 is a longitudinal section through a portion of a composite slab complete.
Fig. 7 is a cross section thereof.
Fig. 8 is a sectional view of a floor construction formed in accordance with
my invention.
Fig. 9 is a section through a modified form of floor span.
Fig. 10 is a perspective view showing the arrangement of metallic strengthening
members for the spans shown in Fig. 9.
Fig. 11 is a section showing a portion of a floor and ceiling construction and the
supporting column therefor.
Fig. 12 is a perspective view of the hoop for supporting the column insulation
and a portion of one of the longitudinal bars.
Fig. 13 is a horizontal section on line - Fig. 11.
Fig. 14 is an elevation showing the manner of tensioning the metallic
strengthening members.
The metallic strengthening members which I employ are formed of flat and
comparatively thin metallic bars A, preferably iron or steel. These bars are
provided at intervals with laterally deflected or partially twisted sections B
preferably formed as shown in Fig. 4 by placing the bar in grooved or slotted
heads C and D separated from each other a distance equal to the length of

page_text: twist to be formed in the strengthening bar, and then engaging a fork or wrench E,
with the center of the section of said bar between said grooved heads and giving
a partial turn thereto. This will form curved shoulders a which when the bar is
embedded in the artificial stone body will form a firm hold or anchor and prevent
the slipping of the bar.
I preferably twist the sections B to stand at the center at an angle of about
ninety degrees to the main section of the bar, as shown in Fig. 1, but this is not
necessary as I may give a greater or lesser twist as in the modifications shown in
Figs. 2 and 3.
To form the composite slab or span, the strengthening bars are formed as above
described and arranged in parallel relation to each other, in a suitable mold or
form, with the main portion of the bars standing on edge, that is with the flat side
of adjacent bars parallel, as shown in Fig. 5, the artificial stone in a plastic state
is then run in so as to fill the mold and completely surround the bars, thus forming
a composite slab, as shown in Figs. 6 and 7, the bars A furnishing the required
tensile strength to the slab and being preferably located in the body in a position
where the greatest tensile strain will be exerted, such as near the bottom surface
of the slab.
The advantage of using thin flat bars twisted at intervals only, for forming
the tension members is, that they may be arranged on edge as above described and
with a given distance between centers of adjoining bars, a greater space is left for
the artificial stone body than with bars of the same strength but of different
cross section. This facilitates the tamping in of the plastic body between the bars
and beneath the twisted portions and ensures perfect contact therewith, thus
forming a perfect lock between the metallic member and the body and also on
account of the greater mass of the body between the bars preventing the same from
cracking when subjected to strains. A further advantage is that the shoulder
formed by the twists is bolder than if a square bar were twisted.
Moreover the bars themselves are much more rigid to withstand vertical strains
when of the shape described than if they were of a round or square cross section
and are also embedded a greater distance in the body and are thus better protected
from the heat in case of fire.
In Fig. 8 I show a floor construction formed by laying bars A across the space
between two beams or girders and then filling in the body portion of artificial
stone upon a suitable supporting mold board, so as to form when complete a
monolith floor, the spans of which are given tensile strength by the bars A.
In Figs. 9 and 10, I show a floor construction of modified form in which instead
of laying the straight bars A, I use similar bars F and G, the one bent into a
U shape and the other double inclined. More in detail the bars F comprise the
horizontal portion c adapted to extend near the bottom of the floor span, the
upturned ends d and the laterally extending supporting arms or hooks e adapted to
rest upon the floor beams or supporting walls.
In Fig. 11, I show a floor-and ceiling construction together with a supporting
column which is insulated or provided with a fire-proof covering which protects it
from the heat in case of a fire.
The bars G are provided with the end supporting arms or hooks f and incline
downward from each end toward the central portion of the span.
I preferably place the bars F, G side by side alternately and when thus arranged
they greatly strengthen the span, as the horizontal portion c is below the neutral
line of the artificial stone body, and the double inclined bars form a truss which
still further increases the strength of the span.
Where the floor spans are of considerable extent I preferably place the metallic
strengthening members under tension to prevent subsequent sagging of the
This may
span.
be accomplished by first hooking one end of each bar over the
flange of the beam, and then by means of a suitable tool, such as shown at H,
Figure 14, gripping the bar and engaging the opposite beam, the bar may be
placed under tension and its end clinched over the beam.

page_text: I desire to emphasize the advantage of thus placing the metallic strengthening
members under tension before the artificial stone body is filled in. As these
members are placed in a portion of the slab span which will be subjected to tensile
strains, they will together with the body in effect form a truss, the body acting aз
the compression member.
By placing the metallic members under an initial tension there will be less
elongation when subsequently loaded and consequently a more limited lateral
deflection or sagging of the span.
The ceiling is formed similarly to the floor construction previously described of
an artificial stone body and metallic strengthening members, but the latter may
be lighter than those used for the floor and spaced further apart. They are
preferably of U-shape and are supported by hooking their ends over the lower
flanges of the floor beam.
The insulation for the supporting columns comprises a series of T-bars extending
longitudinally of the column which are secured in position with their webs extend-
ing outward by hoops L, the latter being also formed of T bars bent around the
column and having their webs apertured to receive the bars K. A wrapping of
wire netting is then wound around and secured to the bars K after which a coating
of artificial stone or similar protecting material is laid on. The columns will thus
be thoroughly protected as the only heat conducting medium extending into the
columns is formed by the thin webs of the hoops or bands L, which are
insufficient to cause any injury.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, declare that what
I claim is
1. The construction of metallic strengthening member for a body of artificia!
stone herein shown and described.
2. The construction of composite floor slab or span herein shown and described.
3. The floor and ceiling construction herein shown and described.
4. The means for insulating or fireproofing the columns herein shown and
described.
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.