Improvements in Macadam Pavement.
Year: 1890

page_text: Date of Application, 27th Oct., 1890
Complete Specification Left, 11th May, 1891-Accepted, 13th June, 1891
PROVISIONAL SPECIFICATION.
Improvements in Macadam Pavement.
We MICHEL HIRSCH and HENRI REINISCH both of Budapest in the Kingdom
of Hungary, Street Paving Contractors do hereby declare the nature of this inven-
tion to be as follows:-
The object of this invention is to improve macadamized roads by preventing or
mitigating the formation of mud during inclement and wet weather which becomes
dust during dry weather thus rendering this kind of road not only extremely
unpleasant and dangerous to health but also increasing considerably the cost of
maintaining and cleansing.
According to this invention the paving of the street is done by macadam in the
ordinary manner, consisting of a layer of 15 to 20 centimeters thickness of ballast-
stones, trachyte, granite or hard sand stone which are placed upon the properly
levelled foundation and pressed in by rollers in the usual way.
Upon this rolled in layer of macadam, the same having completely dried, a
covering layer is spread composed of black pitch, fine and coarse sand (which may
be ground lime stone or sand stone) and mastic (pure bitumen).
This covering layer can be produced in different ways from the above materials
partly from different material and in different mixing proportions for instance
(1)
part of fine sand
part of coarse and rough or coarse ground sand
part of black pitch
15 part of mastic (pure bitumen)
or (2) part of fine ground hard limestone
part of coarse and rough sand
To part of black pitch
To part of bitumen
(3) part of fine ground limestone
part of pitch
part of coarse sand or coarse ground lime or sandstone.
These ingredients of manufacture are selected according to the local conditions
in regard to cost, and possibility of obtaining the necessary materials.
This covering layer is produced as follows.
In the first instance the pitch is melted in large tanks until it has become thin
flowing then the bitumen (mastic) is added. As soon as both have become liquid
the fine sand or fine ground limestone, should the latter be used, is added in small
quantities during continual stirring and lastly the coarse sand or coarse ground sand
or limestone is added: The substance is kept continually hot and flowing during
the mixing and thickflowing during, the use.
This substance istapplied to the macadam layer in a perfectly hot condition. and
by means of hand rollers, which may be warmed if required, it is firmly rolled in
whilst the surface is strewn continually with fine quicksand or fine ground stone in
order to prevent adhesion to the roller. Finally the whole surface is again
bestrewed with fine sand or fine gravel and pressed in by means of a heavy street
roller.
The thickness of this layer is 3 to 7 millimeters after the last rolling in.
As soon as this covering layer has completely cooled down which may be
ccelerated also by the pouring on of water the road will be ready for traffic.
The advantages of this macadam layer are principally cleanliness that is the

page_text: :
formation of mud and dust is prevented, an increased durability of the upper part
of the roadway, that is of the macadam covered by the layer; increased smoothness
of the carriage way without causing slipperiness, as even after the wearing off of
the layer there remains so much of the covering material in the recesses of the
macadam to keep the stone surface smooth like mosaic.
The increased smoothness and evenness of the roadway causes a longer durability
hence a saving of cost of maintenance.
The macadam can be covered repeatedly by the macadam substance according to
requirements so that the macadam covered by said substance lasts 4 to 5 times as
long as non covered macadam.
As with this system the necessity for expensive ballast stone is entirely done
away with the cost of paving is considerably lower, besides for this same reason it is
rendered possible to lay down durable macadam pavements in localities where a
good quality of ballast stone is either not to be had or can only be obtained at
excessive cost. As also instead of the fine or coarse sand, fine or coarse ground
lime or sand stone may be used, the paving of such streets is made independent of
. special kinds of material so that the inaterial which can be obtained the easiest and
at least cost may be used. As the subsequent spreading over of the roads with the
covering layer takes place only at larger intervals the necessity of encumbering the
roads with heaps of stones obviated whilst the repairs or the renewal of the layer
is a perfectly simple operation by which the traffic of the road is very little
disturbed.
Dated this 27th day of October 1890.
HERBERT & Co.,
Agents to Applicants.
COMPLETE SPECIFICATION.
Improvements in Macadam Pavement.
We MICHEL HIRSCH and HENRI REINISCH both of Budapest in the Kingdom
of Hungary, Street Paving Contractors do hereby declare the nature of this inven-
tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement :-
The object of this invention is to improve macadamized roads by preventing or
mitigating the forination of mud during inclement and wet weather thus rendering
this kind of road not only extremely unpleasant and dangerous to health but also
increasing considerably the cost of maintaining and cleansing.
According to this invention the paving of the street is done by macadam in the
ordinary manner consisting of a layer of 15-20 centimeters thickness of ballast
stones, trachyte, granite or hard sand stone which is placed upon the properly
levelled foundation and pressed in by rollers in the usual way.
Upon this rolled in layer of macadam, the same having completely dried a
covering layer is spread composed of black pitch, fine and coarse sand, (which may
be ground lime stone or sand stone) and mastic (pure bitumen).
This covering layer can be produced in different ways from the above materials
partly from different material and in different mixing proportions for instance,
part of fine sand.
1)
16
"
or 2)
coarse and rough or coarse ground sand
"
"
39
black pitch
وو
و,
2-2-263
་པ་
92
39
32
"
"
"
mastic (pure bituunen)
fine ground hard limestone
coarse and rough sand
black pitch
bitumen

page_text: 10
то
preen
"3
"
coarse sand or coarse ground lime or sandstone.
These ingredients of manufacture are selected according to the local conditions
in regard to cost and possibility of obtaining the necessary materials.
This covering layer is produced as follows.
In the first instance the pitch is melted in large tanks until it has become thin
flowing; then the bitumen (mastic) is added. As soon as both have become liquid
the fine sand or fine ground limestone should the latter be used is added in small
quantities during continual stirring and lastly the coarse sand or coarse ground sand
or limestone is added. The substance is kept constantly hot and flowing during the
mixing, and thickflowing during the use.
This substance is applied to the macadam layer in a perfectly hot condition and
by means of hand rollers which may be warmed if required it is well rolled in
whilst the surface is strewn continually with fine quicksand or fine ground stone in
order to prevent adhesion to the roller. Finally the whole surface is again bestrewn
with fine sand or fine gravel and pressed in by means of a heavy street roller.
The thickness of this layer is 3 to 7 millimeters after the last rolling in.
As scon as this covering layer has completely cooled down which may be
accelerated also by the pouring on of water the road will be ready for traffic.
The advantages of this macadam layer are principally cleanliness, that is that
the formation of mud and dust is prevented, an increased durability of the upper
part of a roadway, that is of the macadam covered by the layer, increased smooth-
ness of the carriage way without causing slipperiness as even after the wearing off
of the layer there remains so much of the covering material in the recesses of the
macadam to keep the stone surface smooth like mosaic. The increased smoothness
and evenness of the roadway causes a longer durability hence a saving of cost of
maintenance. The macadam can be covered repeatedly by the macadam substance
according to requirements so that the macadam covered by said substance lasts
4 to 5 times as long as non-covered macadam. As with this system the necessity
for expensive ballast stone is entirely done away with the cost of paving is con-
siderably lower, besides for this same reason it is rendered possible to lay down
durable macadam pavements in localities where a good quality of ballast stone is
either not to be had or can only be obtained at excessive cost. As also instead of
the fine or coarse sand, fine or coarse ground lime or sand stone may be used the
paving of such streets is made independent of special kinds of material so that that
material which can be obtained the easiest and at less cost may be used.
As the subsequent spreading over of the roads with the covering layer takes
place only at larger intervals the necessity of encumbering the roads with heaps of
stones is obviated whilst the repairs or a renewal of the layer is a perfectly simple
operation by which the traffic of the road is very little disturbed.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed we declare that what we
claim is:
The improvement in macadam pavement consisting in covering the macadam
foundation with a layer of the materials hereindescribed substantially as set forth.
Dated this 11th day of May 1891.
HERBERT & Co.,
18, Buckingham Street, Strand, London, W.C., Agents to Applicants.