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Pouring concrete on hot, dry ground leads to rapid
wicking of water into the ground and sides of formwork. This may leave
insufficient water in the concrete for proper hydration.
The Fastfoot® membrane prevents all
moisture loss through the ground and
sides of the footing, producing stronger concrete.
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Fastfoot® prevents the wicking
of moisture from the concrete into ground and sides of the
footing formwork. |
Lumber formed footings provide
no protection from moisture loss through the ground and
edge forms. |
Curing is maintenance of sufficient moisture in the concrete so that
adequate hydration can take place. If concrete is poured on hot, dry
unprotected ground, sufficient water for the hydration process may not be present. This will lead to a significant reduction in strength and durability,
and plastic shrinking cracks may be induced.
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High curing temperature
adversely affects compressive strength (Verbeck and Helmuth
1968) [2] |
When the rate of evaporation or absorption of water exceeds 0.2 pounds per square foot per hour, precautionary measures
should be considered [1].
Data illustrates that inadequate curing in combination with high
placement temperatures impairs the hydration process and reduces
strength. Researchers determined that insufficient curing is more
detrimental than high temperatures on concrete strength [3].
"Fastfoot®
membrane eliminates all evaporation and absorption of water from the sides and bottom of the footing form”, said Andrew Vizer,
avizer@cement.ca, Regional Structural Engineer with the Cement Association of Canada.
"This assists the curing process, producing a stronger, more durable concrete.”
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Probec Ltd. of Turks & Caicos,
edge forms and ground seals all ground level slabs with Fastfoot® |
Pierre
Diotte, President of Probec Ltd., Turks & Caicos Islands,
specializes in the construction of high quality concrete structures.
"The Fastfoot® membrane prevents excessive dessication of
the concrete. We use Fastfoot® under all ground level slabs to
ensure proper concrete curing. Everyone wonders why we have no slab
cracking - the answer is simple, we use Fastfoot®."
Click here for more information on Probec.
To obtain the report on Hot Weather Curing of Concrete (Chapters 12, 13 of
“Design and Control of Concrete Mixtures”),
contact:
The Portland Cement Association, www.cement.org
Phone (847) 972-9044
For the American Concrete Institute's report "Hot
Weather Concreting" [ACI 305R-99], go to the publication's section
of their website
www.concrete.org/bookstorenet/default.aspx.
[1] From “Design and Control of Concrete Mixtures” (EB001.14) Chapters 12 and 13, Portland Cement Association.
[2] From
Verbeck, G. J., and Helmuth, R. H., 1968, "Structure and Physical
Properties of Cement Pastes", Proceedings, Fifth International Symposium
on the Chemistry of Cement, Tokyo, V. III, pp. 1-32
[3]
Section 2.1.3 of the American Concrete Institute report ACI 305R-99
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