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Cook, George H. (ed.) / The Wisconsin engineer
Volume 40, Number 3 (December, 1935)

Synthetic colloid to improve concrete,   p. 57

Page 57

Sjnthetic Colloid to Improve Concrete
INCREASED permanence and resistance to all destruc-
   tive forces will characterize concrete structures of the
   immediate future, according to Dr. Edward W. Scrip-
ture, Jr., director of the Master Builders Research Labora-
tories at Cleveland, where recent research with concrete
and brick mortars foretells the coming of an "alloy age"
in the cement industries.
  The advancement of the construction industries may be
facilitated by the use of certain synthetic colloids, possess-
ing lubricating and lime hardening qualities. The perma-
nence of concrete cannot be taken for granted. The forces
of destruction are minimized by providing a concrete of
increased strength and density resulting in reduced vol-
ume changes.
  Since volume changes are the result of excess water,
concrete approaches its potential strength and durability
as this water is decreased. It has been established that the
excess water, over and above that required for hydration
of the cement but necessary to "place" the concrete, can
be reduced by as much as 20 per cent through the intro-
duction of a gelatinous colloid which paradoxically pro-
vides increased plasticity with less water.
  This lubricating ingredient, by reason of its high puz-
zolanic properties, further reduces volume changes by
the increase of its volume on combining with lime, serving
at the same time to convert the soluble free lime persisting
in simple concrete into insoluble form. The concrete is
thus rendered more water-tight, less porous and therefore
less subject to cracking, checking or crumbling under al-
ternate freezing and thawing. With high resistance to all
corrosive forces, it resists the disintegrating effect which
sea-water has on ordinary concrete.
  The synthetic ingredients which have been investigated
possess properties first discovered by the builders in an-
cient Rome. They used volcanic ash, the first puzzolana,
to strengthen the lime mortars cementing massive blocks
of stone and marble in their temples, aqueducts and baths.
Neglected for many centuries, the value of these lime-
hardening substances has been the subject for increasing
research in recent years.
  A synthetic puzzolana possessing a triple factor for per-
manence has been developed. This not only reduces the
sources of corrosion, but lubricates any given concrete mix
so that the proportion of water can be cut and the conse-
quent volume changes which cause checking and cracking
largely reduced. With the increased density and lowered
porosity resulting, there is less opportunity for destructive
forces to operate on buildings subject to alternate freezing
and thawing.
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December, 1935                                                          
                           Page 57
          50 for $1
as pictured, including your name imprinted
     Others at 2 for 5c to 25c ea.
Page 57
Decembe)- 1935

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