Concrete Roads
and Their Construction
År: 1920
Serie: Concrete Series
Forlag: Concrete Publications Limited
Sted: London
Sider: 197
UDK: 625.8 Con-gl.
Being a Description of the concrete Roads in the United Kingdom, together with a Summary of the Experience in this Form of Construction gained in Australia, Canada, New Zealand and the United States of America.
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8
CONCRETE ROADS
The lower reinforcement was first placed in position. 2 in. from
the bottom. To keep it in place the mesh was stretched over a
2-in. plank, and was supported elsewhere by portions of concrete
passed through a mesh. The wet mixture was then deposited
to a depth of 6| in. and left until next day. After an interval
of 24 hours the top reinforcement was placed and supported in
position I in. above the surface of the lower concrete, and the
wearing coat put in to adepthof in.—| in. below thereinforce-
Fig. 4.—Concrete road under construction in New King Street,
Deptford. The reinforcement for the lower course, stretched over
a 2 inch plank to keep it in position, is seen in the foreground.
ment and 2 in. above it. Thus the depth of the concrete for the
whole was 9 in.
The surface was finished with a wooden float.
The amount of camber was 1 in 48, to obtain which a screed
was used. This, which was very shallow, remained in position until
the concrete had set. It was then removed, the trench extended
down to the first reinforcement and filled with the same mixture
as the wearing coat.
Unwashed Thames ballast graded up to 1 in. was used for the
lower course in the proportion of 6:1, and Mount Sorrel chip-
pings and sand 3 : 1 for the wearing coat; the former passing a
I in. sieve. Fig. 4 shows this road in course of construction.