3.8
FIELD QUALITY CONTROL
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NOTE: Consider the size and complexity of job to
determine if all tests are required.
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3.8.1
Evaluation of Mixture Designs
a.
The adequacy of the mixture design to produce the minimum
specified strength and durability shall be confirmed by testing
field batches, casting concrete in a slab and a wall at the job
using job materials, equipment, and personnel, and testing the
hardened concrete as described herein. The slab shall be at least
2.5 m 8 feet square and have thickness of at least 200 mm 8 inches.
The wall shall be 2.5 m 8 feet long, 1.5 m4 feet high, and at
least 200 mm 8 inches thick. Slump shall not exceed the slump
proposed for the work. Water cure the castings for 7 days.
b.
Test the fresh concrete as follows:
(1)
Slump in accordance with ASTM C 143.
(2)
Air content in accordance with ASTM C 231 or ASTM C 173.
(3)
Unit weight in accordance with ASTM C 138.
(4) For strength, cast nineteen 150 by 300 mm 6 by 12 inch
cylinders in accordance with ASTM C 31/C 31M.
c.
Test 150 by 300 mm 6 by 12 inch cylinders cast under subparagraph
b above as follows:
(1) Measure and weigh each specimen to determine unit weight as
they are stripped from the molds.
(2) Test specimens to be tested at each age for pulse velocity
through concrete in accordance with ASTM C 59/C 59M7.
(3) Two at each age of 24 hours and 3 and 7 days in accordance
with ASTM C 39.
(4) Three at each age of 28, 56, and 90 days in accordance with
ASTM C 39</ RID>.
(5) Two at each age of 28 and 90 days in accordance with ASTM C
496.
d.
Take twenty-five 4-inch cores from each the wall and the slab in
accordance with ASTM C 42. Those to be tested at 7 days or
earlier age shall be drilled on the test date and tested as cored.
Those to be tested at later ages shall be drilled in adequate
time for wet curing before testing. Test cores as follows:
(1) All cores: Pulse velocity through concrete in accordance
with ASTM C 59/C 59M7.
(2) Two cores: Static modulus of elasticity in accordance with
ASTM C 469 at age 28 days.
SECTION 03311
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