The Pensacola journal. (Pensacola, Fla.) 1898-1985, 1922-01-14
DEPENDABLE HIGHWAYS.

way construction TO be started in the
| spring under the added impetus of the
| recently enacted $4,000, 900 federal aid
| BILL These plans are perhaps farther
advanced this year than heretofore,
due to the urgent request of Secretary
OF Commerce Herbert Hoover for
the early letting of contracts as one
means of affording relief from unem-
ployment.
z Up to the present time federal funds
to the amount of s211. 135.s76 have
been allotted to the states as the gov
ernment's share in highway construc-
ton under federal aid since its in
stitution IN 1916, according TO the
latest announcement OF Thomas Z.
Macdonald. director of the L. S. bu-
reau of public roads. The total cost of
all the projects in which the federal
government has shared the expense,
including state and local funds, has
been s49s, 161 $50, the bureau an
nounces.
Practically all forms Of modern
highway types have been constructed
as provided under the various acts
appropriating federal money includ-
ing vitrified brick. macadam, sand
clay, asphaltic and cement concrete
and gravel. Altogether the mileage
built or approved has reached a total
of 2S,135.
In addition to exercising general SUI
pervision over federal aid expendi-
lures, the bureau of public roads is
continually making scientific studies
OF pavement construction and behavior
in order to make available TO highawy
,erty, ;1fn
public in general reliable and official
information concerning modern high
way engineering practice.
These scientific studies are conduct
ed both at the government experiment
tai station at Arlington, and in the
field where the behavior of highways
in actual use may be observed.
As an example of tho nature of the
experiments conducted at the govern
ment station can be mentioned the re-
cent studies of sub-aoil which studies
revealed the fact that concrete pave
ments, for instance. curl up and down
at the edges under the heat OF the sun.
Another instance OF the bureaus ac-
tivities are the, tests of brick and
concrete pavement specimens to deter
mine their ability to withstand impact
or shock as it might be Impaired to
them by the wheels of heavily loaded
motor trucks
A typical illustration OF the work
done in the field by the bureau is the
recent report of a survey OF brick
pavements on rolled gravel, crushed
stone, or Stag bases. This report,
pointing out the adaptability of local
materials, easily available and at al
minimum cost. is made public in the
current issue of the bureaus official
publication. Public Roads
In 1920 the bureau tentatively listed
the various types of pavements ac-
cording to their service value, based
on experience up TO that time, in the
following. order:
/. Brick on concrete base
2. Sheet asphalt on concrete base.
3. Cement concrete.
A. Bituminous concrete.
5. Bituminous maeadam
G. Surface treated macadam.
z Waterbound macadam.
s. Gravel macadam.
o. Gravel.
10. Sand clay
In view OF the fact that concrete
bases were the only type specifically
listed at that time. the recent official
report on an investigation OF rolled
gravel. crushed stone and Stag bases,
pointing out their service records and
length of life, and at the same time
emphasizing the availability OF the
material in territories where gravel
banks, stone quarries or supplies Of
Stag are located, contains conclusions
of wide interest. These conclusions,
as quoted from the official report, are
as fellows.
THE study of these roads would
sions:
THAT the rolled-base type. provid-
ed 1T is properly placed and compacted,
is suitable type for brick construc-
ton where soil conditions are favora-
bic and good natural drainage may be
obtained Under these conditions a
6-inch compacted rolled base should
be adequate. provided a pinch sand
or screenings cushion is used.
"That the rolled base may be sue
cessfully used under ordinary road
conditions. provided the thickness Of
the base is adjusted to meet the prob
able traffic requirements. An S-inch
to 10-inch compacted base with an adj
ditional 2 inches OF cushion should
suffice under all but trunkline high
ways subjected to very heavy traffic
THAT whenever a rolled base is
used bituminous, rather than a
grout filler. should be employed in or
der TO provide q flexible section
throughout.
That in general asphalt filters are
more satisfactory than tar or tar
mastic filters. owing 10 the tendency
of the latter either. TO chip out or flow
in hot weather. leaving the edges OF
the brick unprotected.
That very inferior material as
measured by laboratory tests, may be
successfully used as base material for
brick roads
WoMEN'S ORGANIZATIONS REAL
IzE PERflS OF RED LIGHT.
Cleaning up vice centers is a wo-
mans job" says n member of the