Evening star., 1925-09-15

Bad and deplOrable as the condition
of many of our principally used, worn
out streets are today. as shown in de-
tail in the first article in this series.
printed in The Star yesterday, the
worst is yet to come.
First, every Winter there comes A
period when street repairs must be
suspended when they cannot receive
the constant, daily attention they
must have to keep them from de-
teriorating. and this happens just at
the time when such outlaw" streets,
by the very nature of their construc-
ton, will disintegrate most rapidly.
Second. heavy trucks are tearing a
very large fraction OF our streets and
alleys to pieces. especially where new
and big building developments are
underway. and as our streets Were
never built 10 carry loads that have
recently been made lawful, il is in
evitable that they will break down
with increasing rapidity.
Cannot Skip Repairs.
Here is the simple story of our poor
streets: All of the asphalt and BIZ
luminous pavements-solne 200 miles,
or about $500. 600 square yards. or
almost one-half of all our street sur
face most of which are from 20 TO 40
years old-have to be constantly main
tanned to save them from breaking up.
Those in charge of patching them up
cannot skip a single month. without
the full area deterioratiug.
But there comes a period each Win
ter when this patching work is held
up, partially because the streets are
covered with snow and ice. partially
because the condition Of traffic is such
that the materials to make the repairs
cannot be hauled. Our highway en-
gineers try TO shorten that period as
much as possible by working as late
as they can and by resuming work as
soon as they can. Last year there was
an unprecedented shutdown. when the
asphalt plant was closed for two
months. Work was resumed just in
time to prevent very serious condi-
tion in the streets.
There is that other concurrent con-
6ftion. which is A very material con-
sideration when we are studying what
can be done TO improve the streets of
the National Capital. Just at the time
that these snow and Ice covered as
phalt surfaces are subject to freezing
at night and thawing in the daytime.
because of the low temperature, the
bituminous binder in the asphalt and
nacadam is2at it's minimum strength
Mixing the Cement
Surfacing the top of an asphalt
street (Of which the city has $500, 900
square YARDS is composed of 90 per
cent sand and 10 per cent asphaltic
cement. Now this asphaltic cement
can be made softer or harder as de-
sired, but here in Washington, where
we have probably the widest range in
temperature experienced anywhere in
I he raf1
so that when the warm Summer sun
shines for long period upon it this
binding surface may not become too
soft to carry traffic. In the case of
asphaltic macadam streets (of which
we have more than 1900 900 square
yards), too soft a cement makes the
surface oily and the cement runs off
into the gutter. Extreme care must
be exercised to prevent the street sur
face from becoming SO plastic and flu
ent under the heat of the sun that it
becomes a series of waves and rip
pies. as well as leaving wheel impress
sions, as has happened in many places
The aim is TO adjust the bituminous
binder so that it will be ready to stand
not only considerable heat, but quite
some cold as we'll The action of the
cold makes it brittle, so that the street
surface would become more likely to
crack, Crumble and break up under a
severe Winter. Forethought and years
OF experimentation have been directed
10 making the asphaltic material of
Just that proper constituency that will
not bump in the Summer and crack in
the Winter. Those in charge of the
work have even worked out different
mixtures for the material to be used
on streets that are exposed to the sun
all day from the one used on streets
that are shady most of the time.
Our old asphaltiC pavements get
their worst strain during the period
when they cannot be kept in repair
and when their resistance is lowest.
Hammered to Pieces
During warm weather traffic kneads
the asphalt and bituminous surfaces
and gives them new life; while in the
Winter, when the snow and ice are
freezing upon them, traffic just plain
hammers them to pieces.
Right here, however, it should be
noted that in the bad condition last
Spring that followed the two-month
1ayoff on repair work. all of the as
phalt streets that were 20 years old,
or younger, stood the strain well. The
surface of the older streets was weak
ened because during many years they
had lost strength through the gradual
evaporation or volatiliZation of the oil
IN Ifl6 DltumlnOuS binder.
We have millions of square yards of
streets that are subject to this Win
ter damage. 1t is something that can't
be avoided until the old streets are re-
placed by new streets. All of this is
borne out by the reports of the en-
EineerS. SuperintendentS and fOremen
last Spring that all the Winter dam
age occurred TO the streets more than
20 years old. 1t is doubtful whether
the cost of the intensive repairs dur
ing the Spring period is any greater
than if they had been continuous dur
ing the stopwork period. But if that
layoff period lasted more than
month. an extremely serious condi-
ton would result. Last Spring the
damage was growing fast. and the re-
pair gangs got busy just on the dan
ger line.
Snow Rats Damaging.
Then, too, in spite of the protest
made by some road engineers Of rec
pgnized ability and experience, it is
generally recognized that there Is
very definite harm done TO the roads
ny heavy snowstorm, such as we
experienced last Winter. 1t forces
travel into ruts. and as the snow
packs down and freezes we have
ridges and spots where the packed
and icy snow rests on the pavement
and other places where the pavement
Is cleared. The heavy blows Of traffic
as II bumps over or slews off these
ridges and ice clots and hammers
down on the exposed surfaces must
hurt any street.
This pounding is done mostly by
heavy trucks. Congressman empha-