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3.09 REMOVAL OF FORMS
<br />*Day - degree: Total number of days times average daily air temperature at surface of
<br />concrete. For example, 5 days at a daily weighted average temperature of 60 degrees F
<br />equal 300 day - degrees. Temperatures below 50 degrees F not to be included.
<br />B. Shores shall not be removed until the concrete has attained at least 60% of the specified
<br />strength and also sufficient strength to support safely its own weight and the construction
<br />live loads upon it, but concrete shall be minimum age of 14 days before such removal.
<br />3.10 FAILURE TO MEET REQUIREMENTS
<br />A. Should the strengths shown by the test specimens made and tested in accordance with the
<br />above provision fall below the values given in Table A, the Engineer shall have the right to
<br />require changes in proportions as outlined above to apply to the remainder of the work.
<br />' Furthermore, the Engineer shall have the right to require additional curing on those portions
<br />of the structure represented by the test specimens which failed, the cost of such additional
<br />curing to be at the Contractor's expense. In the event that such additional curing does not
<br />give the strength required, as evidenced by core and/or load tests, the Engineer shall have
<br />the right to require strengthening or replacement of those portions of the structure which
<br />fail to develop the required strength. The cost of all such core borings and /or load tests and
<br />any strengthening or concrete replacement required because strengths of test specimens are
<br />' below that specified, shall be entirely at the expense of the Contractor. In such cases of
<br />failure to meet strength requirements the Contractor and Engineer shall confer to determine
<br />the adjustment, if any, can be made in conformity with Sections 16 and 17 of ASTM
<br />Specification C94 for Ready -Mixed Concrete.
<br />B. When the tests on control specimens of concrete fall below the required strength, the
<br />Engineer will permit check tests for structure in accordance with ASTM Methods C42 and
<br />C39. In case of failure of the latter, the Engineer, in addition to other recourses, may
<br />require, at the Contractor's expense, load tests on any one of the slabs, beams, and columns
<br />in which such concrete was used. Test need not be made until concrete has aged 60 days.
<br />C. Slabs or beams, under load test, shall be loaded with their own weights plus a
<br />super- imposed load of 2 times design live load. The load shall be applied uniformly over
<br />portion being tested in approved manner, and left in position for 24 hours. The structure
<br />shall be considered satisfactory if deflection "D" in feet, at end of 24 -hour period does not
<br />exceed value:
<br />' D equals 0.001 (L x L) /t
<br />in which "L" is span in feet, "t" is depth of slab or beam in inches.
<br />' 12/04 03300 -11 03 -4138
<br />A. Except as otherwise specifically authorized by the Engineer, forms shall not be removed
<br />'
<br />before the concrete has cured as specified above in subparagraph 3.08C and the concrete
<br />has attained a strength of at least 30 percent of the ultimate strength prescribed by the
<br />design, and not before reaching the following number of day - degrees (whichever is the
<br />longer):
<br />Forms for lay -Degree*
<br />1
<br />Beams and slabs 500
<br />Walls and vertical surfaces (non-
<br />water retaining) 100
<br />Walls and vertical surfaces (water
<br />retaining) 150
<br />*Day - degree: Total number of days times average daily air temperature at surface of
<br />concrete. For example, 5 days at a daily weighted average temperature of 60 degrees F
<br />equal 300 day - degrees. Temperatures below 50 degrees F not to be included.
<br />B. Shores shall not be removed until the concrete has attained at least 60% of the specified
<br />strength and also sufficient strength to support safely its own weight and the construction
<br />live loads upon it, but concrete shall be minimum age of 14 days before such removal.
<br />3.10 FAILURE TO MEET REQUIREMENTS
<br />A. Should the strengths shown by the test specimens made and tested in accordance with the
<br />above provision fall below the values given in Table A, the Engineer shall have the right to
<br />require changes in proportions as outlined above to apply to the remainder of the work.
<br />' Furthermore, the Engineer shall have the right to require additional curing on those portions
<br />of the structure represented by the test specimens which failed, the cost of such additional
<br />curing to be at the Contractor's expense. In the event that such additional curing does not
<br />give the strength required, as evidenced by core and/or load tests, the Engineer shall have
<br />the right to require strengthening or replacement of those portions of the structure which
<br />fail to develop the required strength. The cost of all such core borings and /or load tests and
<br />any strengthening or concrete replacement required because strengths of test specimens are
<br />' below that specified, shall be entirely at the expense of the Contractor. In such cases of
<br />failure to meet strength requirements the Contractor and Engineer shall confer to determine
<br />the adjustment, if any, can be made in conformity with Sections 16 and 17 of ASTM
<br />Specification C94 for Ready -Mixed Concrete.
<br />B. When the tests on control specimens of concrete fall below the required strength, the
<br />Engineer will permit check tests for structure in accordance with ASTM Methods C42 and
<br />C39. In case of failure of the latter, the Engineer, in addition to other recourses, may
<br />require, at the Contractor's expense, load tests on any one of the slabs, beams, and columns
<br />in which such concrete was used. Test need not be made until concrete has aged 60 days.
<br />C. Slabs or beams, under load test, shall be loaded with their own weights plus a
<br />super- imposed load of 2 times design live load. The load shall be applied uniformly over
<br />portion being tested in approved manner, and left in position for 24 hours. The structure
<br />shall be considered satisfactory if deflection "D" in feet, at end of 24 -hour period does not
<br />exceed value:
<br />' D equals 0.001 (L x L) /t
<br />in which "L" is span in feet, "t" is depth of slab or beam in inches.
<br />' 12/04 03300 -11 03 -4138
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