Year: 1885

page_text: I, AMZI LORENZO BARBER, residing at Columbia Heights in the City of
Washington, District of Columbia and United States of America, Contractor, 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 manufacture of asphaltic mastic the object of which
is to produce an article easily transported and specially adapted for the laying of
side or foot walks, cellar bottoms, lining of basements, coverings for areas, roofs
and other places, being a substitute for asphaltic mastics made from the bituminous
limestones of Neuchatel, Val de Travers, Seysel, Brunswick, Sicily and other
natural asphaltic rocks and to this end my invention consists in combining
unburned limestone in a finely divided or pulverized condition with an asphaltic
cement said cement being composed of refined Trinidad asphaltum and the residuum
of petroleum or heavy petroleum oil as will more fully appear.
In carrying out my invention I reduce the natural unburned limestone to a finely
powdered and disintegrated condition then heat it and free it from moisture in any
well known manner.
I take of the powdered limestone as above treated about 70 to 80 parts and
thoroughly mix there with about 30 to 20 parts of asphaltic cement.
The asphaltic cement is composed of Trinidad asphaltum which has been refined
and freed as much as possible from earthy or objectionable matter about 80 parts
and the residuum of petroleum or heavy petroleum oil about 20 parts. These
ingredients in about the proportion named are thoroughly incorporated or mixed
together and constitute what I term "asphaltic cement.'
By refining the Trinidad asphaltum and extracting therefrom the earthy and
extraneous matter which detracts from the bituminous and binding qualities of the
asphaltum and putting in its place powdered limestone I increase the wearing
qualities of the pavement or roof made therefrom and furthermore it is not so
liable to disintegrate and be affected by thermal changes.
The crushed and powdered limestone and asphaltic cement in substantially the
proportions named are heated separately and placed in any suitable mixing device
and agitated until they are thoroughly incorporated and the crushed and powdered
limestone is completely coated saturated and impregnated with the asphaltic
cement.

page_text: The mass when thus mixed and reduced to a proper consistency is placed in
suitable molds and pressed into blocks of any convenient or desirable form best
adapted for being easily handled or transported to the place where they are to be
used. I prefer to make these blocks of a size weighing about 50 pounds so they
can be readily handled. The blocks thus formed of the materials just named
constitute a new article of manufacture and will be sold and recognized as such in
the market and will form a substitute for the asphaltic mastics made from the
natural rocks before named.
When the blocks are to be used they are broken by a sledge hammer or other
means into pieces and placed into a tank, cauldron or other suitable receptacle in
which has been previously placed a small quantity of asphaltic cement-heat being
applied so as to reduce the mass to a plastic or semi-plastic condition. When the
mass has been reduced to the proper condition of fluidity from 25 to 60 per cent of
small gravel or grit is added and thoroughly incorporated therewith by stirring.
The composition or mastic thus formed is now laid on a suitable foundation in
the usual manner of laying such pavements and the surface is finished in the
manner customary in the laying of Neuchatel or other asphalt mastics made from
natural rock. By Trinidad asphalt I mean the asphaltum from the well known
lake at Point La Brea in the island of Trinidad, B. W. I. as this deposit has exactly
the qualities required to produce the desired result.
I do not wish to confine myself to limestone powder as fine sand of suitable
quality may be successfully substituted for a part or all of the limestone powder.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1. As a new article of manufacture a block composed of pulverized limestone,
refined Trinidad asphaltum and residuum of petroleum or its described equivalent
as set forth.
2. An asphaltum mastic composed of refined Trinidad asphaltum, residuum of
petroleum or heavy petroleum oil and pulverized and ground limestone combined
in the manner and in the proportions set forth.
3. A paving composition consisting of an asphaltic cement such as described,
pulverized and ground limestone and small gravel or grit combined in the manner
and in substantially the proportions set forth.