AN IMPROVED METHOD OF PREPARING, OBTAINING, AND UTILIZING AN ARTIFICIAL ASPHALTOS
Year: 1878

page_text: LETTERS PATENT to André Michel Adrien Gobin, of Lyon (France), Engineer,
for the Invention of "AN IMPROVED METHOD OF PREPARING, OBTAINING, AND
UTILIZING AN ARTIFICIAL ASPHALTOS."
Sealed the 15th October 1878, and dated the 9th May 1878.
PROVISIONAL SPECIFICATION left by the said André Michel Adrien Gobin
at the Office of the Commissioners of Patents on the 9th May 1878.
ANDRÉ MICHEL ADRIEN GOBIN, of Lyon (France), Engineer.
"AN IMPROVED
METHOD OF PREPARING, OBTAINING, AND UTILIZING AN ARTIFICIAL ASPHALTOS.”
My Invention is based,―
Firstly. Upon the composition of the new product.
"
Secondly. Upon the process of manufacture, which consists in mixing the mate-
rials in the hot state aftor having deprived them by previous heating of the water
which they contain.
And, Thirdly. On the application of this asphalte as a new description of paving
for roads, and other surfaces.
By the composition and the process of manufacture of the new asphalte I obtain
a product as hard, and, at least, as tenacious as natural asphalte, and which does
not soften more than the latter at high temperatures.
The chief advantage of this composition and the mode of manufacture is that it
avoids the shrinking, which in time always occurs in known artificial asphaltes, and
even to some extent in natural asphaltes.
The materials I employ are found abundantly in England, France, and most
parts of the world. The process of manufacture is simple, and does not require
complicated apparatus.
The new product can therefore be employed at once, and almost everywhere on
a large scale, and will be of great advantage in making paths and roads, because it
is cheaper than natural asphalte.
My asphalte is composed of the following materials in about the proportions
stated, viz.- -Bitumen from schist (soft at the ordinary. temperature), 15 parts;
-

page_text: pitch from coal (solid at the ordinary temperature), 35 parts; powdered coke (not
too fine), 10 parts; pulverized limestone (more or less soft), 130 parts; fine gravel,
160 parts.
The proportions will be modified in accordance with the state of the materials,
and according to whether it is wished to obtain an asphalte more or less hard or
more or less resistant at high temperatures.
For very hot climates Trinity bitumen (bitumen de la Trinité) should be added to
the bitumen from schist.
The mode of preparation is as follows:-The bitumen and pitch are melted
together in boilers; and when the froth, which is formed on the surface, and which
arises from the disengagement of the moisture contained in the materials has
entirely disappeared, the other materials are added. The powdered coke and the
pulverized limestone are previously mixed roughly together, and heated for a certain
time to upwards of 212° Fahrenheit to drive off all moisture which they contain,
and this hot powder deprived of all moisture is mixed with the melted bitumen in
the boilers. Finally, the gravel is added after having been heated and well dried,
and before it has cooled.
This asphalte is of great density; at 120° of heat it does not soften more than
the natural asphalte of footpaths, and it is more resistant.
If the manufacture is carried on far from the place of employment the mixture
is made as above described without adding the gravel. A mastic is thus obtained,
which must be submitted to a second melting in order to add the gravel at the time
of employment.
This asphalte may be applied in lieu of natural asphalte for pavements, footpaths,
terraces, and so on. It can also be moulded into the form of paving stones, which
will make a roadway having all the advantages of roadways formed from melted
or compressed asphalte, and without their inconveniences, besides being much
cheaper.
The manner in which I produce this new pavement is as follows:-I increase the
proportion of gravel to, say, 190 parts; and I mould the asphalte into prisms of,
say, 8 inches long, 6 inches wide, and 4 inches deep. These blocks are placed like
ordinary paving stones on a layer of well-dressed gravel or sand, and well beaten
or compressed by machine. The joints of the blocks have bitumen run in hot,
or hot sand or dry sand, which is impregnated with a little coal tar or resin
oil; or the joints may be left in the natural state if the blocks are well placed
together.
In some cases I replace the bitumen from schist with other similar bitumens,
such as petroleum, Trinity, and tallow.

page_text: the said André Michel Adrien Gobin in the Great Seal Patent Office on the
16th October 1878.
ANDRÉ MICHEL ADRIEN GOBIN, of Lyon (France), Engineer. "AN IMPROVED
METHOD OF PREPARING, OBTAINING, AND UTIILIZING AN ARTIFICIAL ASPHALTOS."
My Invention is based,-
Firstly. Upon the composition of the new product.
Secondly. Upon the process of manufacture, which consists in mixing the mate-
rials in the hot state after having deprived them by previous heating of the water
which they contain.
And, Thirdly. On the application of this asphalte as a new description of paving
for roads, and other surfaces.
By the composition and the process of the manufacture of the now asphalte I obtain
a product as hard, and, at least, as tenacious as natural asphalte, and which does not
soften more than the latter at high temperatures.
The chief advantage of this composition, and the node of manufacture is that it
avoids the shrinking which in time always occurs in known artificial asphaltes, and
even to some extent in natural asphaltes.
The materials I employ are, found abundantly in England, France, and most
parts of the world. The process of manufacture is simple, and does not require
complicated apparatus.
The new product can therefore be employed at once and almost everywhere on
a large scale, and will be of great advantage in making paths and roads, because it
is cheaper than natural asphalte.
My asphalte is composed of the following materials in about the proportions
stated, viz. :-Bitumen from schist (soft at the ordinary temperature), 15 parts;
pitch from coal (solid at the ordinary temperature), 35 parts; powdered coke (not
too fine), 10 parts; pulverized limestone (more or less soft), 130 parts; fine gravel,
160 parts.
The proportions will be modified in accordance with the state of the materials,
and according to whether it is wished to obtain an asphalte more or less hard or
more or less resistant at high temperatures.
For very hot climates Trinity bitumen (bitumen de la Trinité) should be added
to the bitumen from schist.
The mode of preparation is as follows:-The bitumen and pitch are melted
together in boilers; and when the froth, which is formed on the surface, and which
arises from the disengagement of the moisture contained in the materials, has
entirely disappeared, the other materials are added. The powdered coke and the
pulverized limestone are previously mixed roughly together and heated for a certain
time to upwards of 212° Fahrenheit to drive off all moisture which they centain;
and this hot powder, deprived of all moisture, is mixed with the melted bitumen
in the boilers. Finally, the gravel is added after having been heated and well
dried, and before it has cooled.
This asphalte is of great density; at 120° of heat it does not soften more than
the natural asphalte of footpaths, and it is more resistant.
If the manufacture is carried on far from the place of employment the mixture is
made as above described without adding the gravel. A mastic is thus obtained,
which must be submitted to a second melting in order to add the gravel at the
time of employment.
This asphalte may be applied in lieu of natural asphalte for pavements, footpaths,
terraces, and so on. It can also be moulded into the form of paving stones, which
will make a roadway having all the advantages of roadways formed from melted
or compressed asphalte, and without their inconveniences, besides being much
cheaper.

page_text: The manner in which I produce this new pavement is as follows:-I increase
the proportion of gravel to, say, 190 parts; and I mould the asphalte into prisms
of, say,
inches long, 6 inches wide, and 4 inches deep. These blocks are placed
like ordinary paving stones on a layer of well-dressed gravel or sand, and well
beaten or compressed by machine. The joints of the blocks have bitumen run in
hot, or hot sand or dry sand, which is impregnated with a little coal tar or resin
oil; or the joints may be left in the natural state if the blocks are well placed
together.
.
This pavement will possess all the advantages of roads made of compressed
natural asphalte; it will have the same smooth surface so suitable for carriage
wheels, and for cleansing; it will prevent noise, will be less slippery on account of
the transverse joints, and of the gravel it contains; it will be more elastic, because
sand or gravel takes the place of concrete for the foundation; it will be more
durable, cheaper, and repairs can be done at any season and with greater rapidity,
thus overcoming the great inconvenience experienced with compressed asphalto.
The removal of the holes caused by settling of the subsoil can be quickly
effected by picking up, and the few damaged blocks can be easily replaced by
others.
These advantages will be much appreciated for the busy roads of large towns,
also for tramways and platforms of railway stations.
The pavement can also be employed in places where the temperature is too high
to permit of the use of ordinary compressed asphalte.
From the foregoing description it will be understood that my Invention is based
on the composition of the asphalte, on its preparation, and on its applications.
The object is to have an asphalte which is hard, tenacious, elastic, not liable to
soften at high temperatures, not liable to shrink in course of time; properties
which are chiefly due to the employment of the coke in the mixture, to the use of
bituminous matters deprived of their essential oils, to previously removing from
the materials the moisture which they may contain, either naturally or otherwise,
and to mixing them in a hot state.
I also apply these new features to the manufacture of mastics from natural
asphalte, and from other artificial asphaltes.
Another feature is the placing of my new asphalte in blocks upon sand instead of
upon a concrete foundation, so as to give great elasticity to the roadway or other
surface.
In some cases I replace the bitumen from schist by other similar bitumens,
petroleum, Trinity, tallow, &c.
And having now described the nature of my said Invention and in what manner
the same is to be performed, I declare that 1 clain, the preparing, obtaining, and
utilizing of artificial asphaltos or asphalte, substantially as herein-before described.
In witness whereof, I, the said André Michel Adrien Gobin, have hereunto set
my hand and seal, this Fourth day of October, One thousand eight hundred
and seventy-eight.