The Republican. [volume] (Oakland, Md.) 1877-current, 1910-03-31
A WELL Ru1Lr coNCRErF ROAD.

WELL BUILT CONCRETE RoAD.
From Good Roads Magazine. New York;
TO do the necessary grading thing.
ditching, pntting in of manhoes. build
ing shoulders and. in fact. doing all
the work but the actual concreting.
Ninety-eight cents barrel was paid
for cement and - cents a yard for
sand. and the prices of limestone and
crushed cobbIe are shown in the speci-
ication. The average haul was about
two miles. Two thicknesses of three
ply tar paper were used in the three
twenty-five foot sections. the fourth
section being made half an inch wide
and filed with composition of four
parts soft pitch to one part Trinidad
asphalt. to which was added per cent
Of still wax. the whole heated and
poured into the joint in IA boiling state.
A strip Of southern pine was also used
as an experimental joint.
The following specifications are those
under which such road can be ~
structcd:
All cement used should be portland [.
ment OF American manufacture. No more
than per cent OF the cement should fan
to pass through a No. lOU sieve nor more
than . per cent should tail to pass
through a No 2OU sieve and it should
stand a test OF l5O pounds per square inch
tensile strain when made into prIQuets
ana exposed IN air until final set and the
balance OF tUenty-four hours Immersed in
water. one day IN air ana six days IN
water should show a tensile strength OF
at least 400 pounds one day in air and
IA
a tensile strength OF at least $50 pounds.
and when mixed in proportions by weight
OF one OF cement TO three OF sand and ex-
posed IN air one day and In water six
days it should stand a tensile strain of at
least $50 pounds ana IN twenty-eight days
a strain ct least 200 pounds per square
inch.
Sand used in making concrete should be
clean, dry. crushed quartz. trap rock.
granite or well graded bank. lake or river
sand. passing a NO 20 sieve OF No. %
wire. ana De so graded TO contain fine
ana coarse particles OF the same grade OF
material, the coarse particles to predom-
mate.
Stone for concrete can be purchased at
the following prices per ton, which prices
represent the actual cost OF the stone laid
down: Two inch, 81 so per ton: chips. $50
per ton; screenings, s. per ton.
In case ct hard stone. weights should be
OF ZOO pounds per cubic yard tor two
inch stone 100 POUNDS per cubic yard
for chips and ESQ pounds per cubic yard
for screenings
Concrete for the first course should con-
sst OF one part OF cement two parts of
sand and five parts OF broken limestone
and for the second course one part OF &C.
ment, two parts OF sand and three parts
OF hard stone evenly mixed.
In placing the concrete In position in
the construction of the pavement the men
should place the concrete where directed
and so as to keep the different layers of a
uniform thickness. Each layer should DO
we'll tamped with an approved tamper
and as directed by the engineer.
The second course must be laid within
twenty minutes after the first course is
completed and placed and tamped same as
the first course. And at night or at any
other time when the work Is discontinued
all the work of both LAYERS should be conn :
pleted up TO common expansion Joint.
In otner words no section OF pavement
should De allowed to be left unfinished for
a longer period Of time than twenty min
utes il WORK thereon has been started.
After the second course OF concrete is
laid and unit IT has thoroughly set it
shoold be protected from the sun by
canvas OF other suitable covering.
When tGe concrete is sufficiently hard to
warrant, This covering should DE removed
ana the concrete covered with a layer of
sand or gravel about one inch in depth
and sprinkled and Kept damp to prevent
1ue surface of the concrete from drying
out too rapidly. which covering should be
left on the concrete tor a period of seven
days -
Expansion Joints should be plG Y in
said pavement every twenty-five Ny
actual measurement. such Joints y be
made by placing in position a one<half
inch thick n hprn
of the same width as the thickness of the
road metal and cut so to conform to
the finished surface OF the pavement.
This board should be removed after the
concrete has become set. but not until
twenty-four hours nave elapsed after the 4
placing OF the concrete on both sides of l
the board. And when the board Is re-
moved the space left by ii should he filled
with a filler OF the following composition:
Four parts soft pitch and one part as /,
phalt trefined Trinidad. TO which NIX .ure
must be added per cent OF still wax, the
whole TO be heated and poured into the
joints in boiling state.