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Cold Weather: The
contractor shall comply fully with the provisions of ACI
306.1-90 as modified below: |
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Average daily
temperatures as defined in ACI 306.1-90 will be determined and
recorded by the City Engineer. |
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Concrete temperatures
will be determined through the use of high-low thermometers
placed and operated by the City below insulated blankets, or
where the concrete is uncovered, by checking air temperatures.
Uncovered concrete which has been subjected to freezing
temperatures of any duration during the first 24 hours will be
considered "frozen," and shall be rejected. |
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The months of
December, January and February will be considered Cold Weather" and
will require concrete protection, regardless of
temperature. |
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Concrete shall reach
75% of its design strength prior to backfilling. This strength
can be determined through the use of field cured cylinders,
made and tested at contractor's expense. Concrete must have 5
days where the average daily temperature is above 50 degrees F
prior to backfilling unless field cured cylinders are taken.
These days do not need to be consecutive. |
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Concrete operations in
hot weather shall conform to Section 402.07 (a) of the
Standard Specifications. |
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(History: Ord. STR-2295 §6, 2001; STR-2189 §1, 2000;
CSW-498 §3(D-1) 69)B. |
