Improvements in Artificial Stone for Street Pavements, Pathways, and like Purposes, and in the Method of Producing the same.
Year: 1896

page_text: Date of Application, 24th Aug., 1896-Accepted, 30th Jan.. 1897
Improvements in Artificial Stone for Street Pavements, Pathways,
and like Purposes, and in the Method of Producing the same.
A communication from JOHANN JUNGBLUTH, of 86 Frieson wall, Cologne on
Rhine, in the Empire of Germany, Architect.
I, ALFRED JULIUS BOULT of 111 Hatton Garden, in the County of Middlesex,
Chartered Patent Agent, do hereby declare the nature of this invention and in what
mannor the same is to be performed, to be particularly described and ascertained in
and by the following statement:-
The object of the present invention is the manufacture of artificial stone by the
action of very high pressure-compression-on the materials employed, which are
in the main formed by the top layer, binding medium and ground mass.
Tho top layer consists of asphalte powder which is brought to a glowing
temperature before being introduced into the stone mould.
The binding medium consists of 3 differently prepared substances.
The ground material consists of a stone of rocky hardness of porous nature, as
porous basalt lava, such as is found in the neighbourhood of the Laucher lake and
elsewhere and is employed in three different degrees of size.
a. One part in the shape of fine powder.
b. One part in pieces of the size of peas say, about five millimetres in
.diameter.
c. One part in pieces of the sizo of small nuts of about ten-twelve milli-
metres in diameter.
The process for the use of the three chief masses or materials, in order to obtain
by their compression in a mould artificial stone of such qualities as have been
unattainable hitherto as regards hardness, appearance, resistance, to the influence
of temperature and indestructibility, is as follows;-The ground and the binding
materials are at first introduced into a mould in a warm and slightly damped state
whereas the top material following afterwards is introduced in quite a hot state,
very near the glowing state. The mould is then closed and the high pressure
follows that is to say the compression of separato parts.
It is to be specially pointed out that the ground and binding materials are
introduced in only a very slightly wetted state, as this is essential in order to
retain their complete power of setting nearly to the time when they are placed in
the mould. The real setting, that is to say the setting of the artificial stone itself,
then takes place, in a natural way after the stone has been taken out of the mould,
and may take a number of days.
The purpose of the porous rocky stone is to give by its porosity an opportunity
to the top material to combine ultimately with it so that a non-porous, strong
material is produced, which is capablo of resisting even the hardest shocks and
when laid in mixed layers gives an indestructible surface of good appearance.
D

page_text: The purpose of the action of especially high pressure, say of about 301) atmo-
spheres after the three principal masses bave been placed in the mould is, bosides
producing a close compression of the pulverised and grain-like ingredients, chiefly
to produce a stone in which the ground mass is combined with the asphalte-top
mass into one whole by means of a heavy and strong pressure.
By this means is attained a complete mutual penetration of the ground-and top
layers in the separation plane of the two layers so that a subsequent separation,
breaking off or loosening of the separate ingredients even whon subjected to the
greatest strains is completely avoided. The purpose of the top layer is to obtain
a surface which in respect of strength answers to all the requirements of heavy
street traffic and on account of the layer being comparatively thin, costs much less
than if the whole stone were prepared as hitherto of such top-layer.
When taken out of the mould, the stones or slabs are exposed to a water spray
which has the advantage of completing the setting under the action of the oxygen
of the air, in a uniform and slow manner in about 27 days, so that the hardening
effect penetrates even into the inmost parts of the artificial stone.
Having now particularly described and ascertained the nature of the said inven-
tion, as communicated to me by my foreign correspondent and in what manner the
same is to be performed, I declare that what I claim is :-
1. An artificial stone consisting of a top layer of pulverised asphalte, a binding
material of ground Portland cement powdered unslacked lime and ground trass,
and a ground-material of hard porous stone in the form of powder and small
pieces of about 5 millimetres and 10-12 millimetres in diameter, substantially as
described.
2. The process of forming artificial stone as described, characterised by the
ground and binding materials being introduced into the mould in a very slightly
wetted condition, the top material ou the contrary being introduced in a very hot
and almost glowing state the intimate combination of the masses in the mould being
effected by the action of a high pressure, of about 300 atmospheres and the setting
of said masses, after they have been removed from the mould, taking place under
the action of a water spray during the necessary period for setting.
Dated this 24th day of Amanat 1908
BOULT & WADE,
Agents for the Applicant.