The Cairo bulletin. (Cairo, Ill.) 1???-1928, 1910-04-29
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IN ASPHALT PAVING.
Cost and Composition in Its Manufac-
ture and Repair.

The first asphalt. pavement in the
world was laid In the city Of Paris
about fifty-one years ago. About six
million square yards, or about three
hundred linear miles. or European
streets are now paved with that mate
rial
twenty-five years ago about twelve
miles, or less than one-fifth of one per
cent, OF the paved streets OF the cities
OF the United States. were paved with
asphalt Today, about twenty-five hun
dred miles OF streets in the United
States, embracing an area approxi-
saately forty million square yards,
are paved with asphalt This repre-
SCENTS In first cost, an investment OF
$l00,000.0 600. and, including the cost OF
repairs and resurfacing, a total outlay
OF not less than $l50000.000
Classifying by percentages, the ma
terials comprising an asphalt pave
ment of 6-inch concrete base, "a inch
binder and 2 inches Of asphalt topping,
as usually laid, will run approximate
ly as follows: Stone. ST. per cent:
sand, S44 per cent; cement, 63 per
cent; stone dust, 3.3 per cent; asphalt,
3.3 per cent; and oil 06 per cent. Thus
It will be seen that asphalt forms not
exceeding 3.3 per cent OF the materials
of an American asphalt pavement, and
ranges as low as 1.S per cent when as
phalts rich In bitumen are used Fully
so per cent OF the American asphalt
paverhents may be termed an artificial
bituminous sandstone, the wearing
surface being 80 per cent sand and 10
per cent bituminous mastie.
The European asphalts, until within
few years ago, We're all made from
the crushed powder Of natural lime-
stone, of which 80 per cent Is very
finely crushed limestone, and 10 per
cent Is bituminous mastic These as
phalts were compact, but very slip
perry, the gradients upon which they
quenee. This, in the early literature
upon asphalt pavements, gave rise to
the statement that they could not be
used upon greater than per cent.
grades. Experience has demonstrated
that the American asphalt payements
are practical for any traffic upon
grades up to per cent, and with short
sections at intervals upon grades very
much sleeper, in fact, as steep as AZ
per cent
Until within few years the wearing
capacity of an asphalt pavement was
considered SO limited as to confine Its
use to parks and light traffic streets,
Pevements laid in European cities, no.
tably in Paris, by an American COM
pany In 1886, based upon the sand and
bituminous composite, failed complete
ly TO meet the dense traffic encount-
creed, and within six months after be-
moved.
Within the past ten years successful
asphalt pavements have been laid by
the same American company in Lon
don, Glasgow and Paris, and the gran
lite pavement Of several New York
city streets have been successfully and
satisfactorily displaced with American
asphalt payements.
Up to 1893 asphalt specifications
were practically closed TO the use of
all asphalts but one, that coming from
one portion of Trinidad island, on the
South American coast. Engineers of
the cities had limited knowledge of the
subject in preparing specifications and
placed dependence mainly upon the
guaranteed period of maintenance. in
spection of the asphalt portion of the
pavement being farce. The author
believing that better progress could be
made and lower prices obtained, pre-
pared in 1898 specifications for the city
of Omaha admitting oil aaphalts under
the usual bond and guarantee provi-
sions. In order to succeed in his eff
forts 1t became necessary to induce
Washington, New York, Chicago, Dem
yer and other cities to cooperate.
which was done and proved successful.
Litigation followed, and each attempt
of those early in the field was met with
stubborn resistance, but the opposition
to open specifications proved futile and
a field for asphalts from the mines
of California, Utah, Kentucky, Vene-
2uela and other localities, In addition
to those of Trinidad, was developed.
Prices, however, as a result of bitter
competition, became ruinous, the cost
OF paving dropping In 1895 and 1897 In
many localities. fully 60 per cent The
public was the ultimate winner, frcm
the more general knowledge gained and
the outcome has not only been better
pavemcnts from the Trinidad product,
but also keener knowledge Of the
whole subject and good payements are
now made from artificial asphalt pro-
duced from residuums of the California
oil, and also from asphalt from Vene-
zuela, Cuba and other other sources
Good Roads Magazine.
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