Evening star. [volume] (Washington, D.C.) 1854-1972, 1925-05-02
AMAZING PROGRESS.
IN CEMENT WORK.
Office Buildings, Houses,
Roads and Bridges Built at
Surprising Speed.
BY j. G. ROYLE.
Special Dispatch to The Star.

Special Dispatch to The Star.
NEW YORK, May 2.-Homes. in
dustrial buildings. bridges. dams.
pavements and roads, in construction
of which concrete is used. are being
made twice as fast today as they were
10 years ago. according to cement ex-
perts. Through the time and labor
saving devices developed in construc.
ton work in the last decade, living
conveniences and dwellings now are
available to American families who
never were able to secure them be-
fore.
One of the chief savings has been
in time of construction. always prime
factor in costs. In the last IL months
II stories of a 19-story apartment
house in Chicago were erected in 80
days. A concrete bridge with a 81
foot span was completed across a
Maryland river in less than four
weeks. A new Buffalo stove factory.
256 feet long, Sc feet wide and 2 stories
high, was constructed of concrete in
GO days.
Road Work Speeded.
1t is in concrete road construction,
however, that new methods have
shown the most pronounced advance.
In 1910 it required at least month
to build a mile of paved highway.
Road commissioners then let con-
tracts in units of one TO three miles.
Today a mile of paved road can be
completed in Is days and contracts
are in units of 10 to 20 miles.
Improved machinery is responsible
for much of this saving. Ten years
ago the capacity of the ordinary con-
crete paving mixer was a two sack
batch of IL feet of dry material.
The mixer of today turns out double
that quantity every two minutes. In
some cases central mixing plants are
employed from which the mixed con-
crete is trucked to its final resting
place from 6 to 10 miles away.
Central Mixing Plants.
Permanent central mixing plants,
where a builder can drive up. get his
loads of concrete all ready for pour
ing and carry the material to his
building site, are found in many
cities. This has been made posi-
BILE through utilization of motor
trucks. The Sloss Sheffield Steel
Corporation of Birmingham now sup
plies concrete made from it's own
cement and Stag heaps in truck or
freight carlots for transportation
within a fairly wide radius.
The construction of the Wilson
Dam at Muscle Shoals, the world Z
largest concrete job, is a tribute TO
Three central mixing plants were
employed. two of which used two
yard mixers and the other, two A.
yard machines. These supplied
1 ,291 900 yards of concrete for the
dam. An undertaking of such a size
could not have been attempted I'M
der the methods of 20 years ago.
Paving Mixers Great Help.
On road and street construction a
paving mixer is now used which
travels under its own power. This
usually Is equipped with a gasoline
motor and caterpillar treads. II
places concrete by means of bot
tom-dumping bucket moving on 6
boom.
Similar improvements have beer
made in providing the sand. grave
and crushed stone for concrete
Mammoth plants produce as much as
a trainload a day Of carefully pre-
pared and graded materials. Grea'
changes also have taken place in the
| making of cement itself. The 20-foo
kilns formerly used have been re
placed by gigantic steel cylinders, PSI
feet long, in some instances. I'm
mense cruShers capable of cracking
huge stone block weighing as much
| as 100000 pounds are in operation
The average output of the American
cement plant has risen in consequence,
from 400 barrels to well over 5000
barrels a day.
Output Above Demand
These improvements and saving
| methods will permit the placing o.
nearly 5000 miles of concrete rura
| highways in the United States in 1925
They have made possible the building
of the Hetch Hetchy Dam in thu
| Sierras, back of San Francisco tn,
| 627-foot concrete wireless tower a
Toxic, the highest stone work struc
ture in the world and the American
Furniture Mart in Chicago. the larg
est multi-story building in the coun
| try.
| Production of cement now is some
what above building demands, accord
| ing to B. F. Affleck. former presiden
| of the Portland Cement Association
He believes plant capacity will be @
per cent above requirements for SOM
years. He added, however, that con
gestion of the market was being
] avoided by gradual curtailment of ex
| ceSSive output.