Webster City freeman. [volume] (Webster City, Hamilton County, Iowa) 1884-1946, 1911-12-05
How TO MAKE
GOOD PAVING
D. W. Norris Gives Information
Concerning the Various
Mixtures Proven
Satisfactory.
ALMOST THE PROBABLE COST
Here is Something Everyone Inter
ested in the Paving Question
Should Read.

A few days ago the Freeman-Trib-
une addressed a letter to Mr.. Norris
asking information as to paving
specifications, and today's mail
brought the answer. Some of our
readers may be curious to know how
1t happened that the Freeman-Trib-
une sought advice from an editor
upon the question OF paving The
answer is easy. The Marshalltown
es-Republican is regular visi-
tor at this Office and no exchange is
more carefully read. The Times
Republican has been carrying on a
paving campaign Of education the
past three or four years and the
Freeman Tribune has been interest
ed in that question ever since our
council decided to pave three years
ago. Accordingly, the articles APP
pearing from time to time in the
Marshalltown paper have been read
with unusual interest and they bore
the stamp OF sincerity and the self
evidence Of thorough knowledge up
on the question. Hence Mr.. Norris
was asked to write an article for the
Freeman-Tribune, which he did
promptly and without price. We be-
lieve he is rendering the public a
great service. 1t is absolutely GER
tain that he saved the people Of
Marshalltown many thousands Of
dollars by his persistent and fear
less fight against the patented and
monopolized paving materials. II ev-
cry city had a D. w. Norris to take
up the cudgel for the square deal in
public works there would be little
left of graft and bribery.
In response to our inquiry as to
specifications for concrete paving
Mr.. Norris writes as follows.
| Editors Freeman-Tribune: In re-
spouse to your request for an article
- to proper mixture Of materials to
use In concrete pavement / would
call your attention to the specifica-
lions used at Mason City, Eldora and
Usage as ideal for the double course
concrete, and to those used at Sioux
City for the single course or one
pour job. Engineers differ as to the
comparative merits Of the two kinds
and do not think you will go
wrong on either. We adopted the
double course pavement in MARSHALL
town.
WHAT NOT TO DO.
But In no event should you ever
speak Of a concrete pavement to be
made Of cement and sand alone
without coarse aggregate of exact
proportions. / have noted in your
paper reference to 1T mixture.
This is a very common error and
even some engineers fall into it..
Concrete scientifically is merely a
mixture OF enough cement with sand
to completely fill all the voids or
space between the particles of sand
and thus cement or bind all parti-
cles of sand together into mono
lithic mass. This is the mortar aud
should then be mixed with broken
rock or gravel In such proportions
as to completely fill all the voids be-
tween the pieces of rock or gravel
and cement them together with NOR
tar. You could use all sand but not
In any proportion weaker than 1:s
and preferably LIZ, but In this pro-
portion the mortar costs more than
coarse aggregate, so it is cheaper to
Increase the mass by adding as much
coarse aggregate as can be done and
still have all voids filed by the NOR
tar. When concrete is made of
IA or i:6 mixture 1t is done on the
theory that there is certain
amount OF gravel in the sand, but
the facts are that mine-run gravel
has about as. little stone In it as
there are Jumps in mine-run coal
andand no experienced engineer VIII
ever specify mine-run gravel in cx-
cess of Ia mixture. II is far better
to screen the gravel out OF the sand
and then put the sand and stone
back in correct proportions of two
parts or two and half parts sand
to five parts stone. This will give
strong mortar OF 1:2 or 1:2h and
there will be no weak spots in your
pavement where the mine-run grav-
ell ran too strong OF sand and con-
sequently weakened the mortar. Cor
rect proportions Of material are the
most important essentials In mixing
good concrete. Never take chances
on mine-run gravel. The concrete