deviation. Identify samples so taken in a manner that they can be
segmented from other tests. Obtain at least one sample for each
100 cubic yards, or fraction thereof, of each design mixture of
concrete placed in any one day. When the total quantity of
concrete with a given design mixture is less than 38.2 cubic meters
50 cubic yards, the strength tests may be waived by the
Contracting Officer, if in his judgment, adequate evidence of
satisfactory strength is provided.
3.8.3
Testing
3.8.3.1
Slump Tests
ASTM C 143. Take concrete samples during concrete placement. The maximum
slump may be increased as specified with the addition of an approved high
range water reducing (HRWR)` admixture provided that the water-cement ratio
is not exceeded. Perform tests at commencement of concrete placement, when
test cylinders are made, and for each batch (minimum) or every 8 cubic
meters 10 cubic yards (maximum) of concrete.
3.8.3.2
Temperature Tests
a.
Test the concrete delivered and the concrete in the forms.
Perform tests in hot or cold weather conditions below 10 degrees C
and above 27 degrees C below 50 degrees F and above 80 degrees F
for each batch (minimum) or every 8 cubic meters 10 cubic yards
(maximum) of concrete, until the specified temperature is
obtained, and whenever test cylinders and slump tests are made.
b.
Determine temperature of each composite sample in accordance with
ASTM C 1064. When the average of the highest and lowest
temperature during the period from midnight to midnight is
expected to drop below 4 degrees C 40 degree s F for more than 3
successive days, concrete shall be delivered to meet the following
minimum temperature at the time of placement:
(1) 13 degrees C 55 degrees F for sections less than 300 mm 12
inches in the least dimension
(2) 10 degrees C 50 degrees F for sections 300 to 900 mm 12 to 36
inches in the least dimension
(3) 7 degrees C 45 degrees F for sections 900 to 1800 mm 36 to 72
inches in the least dimension
(4) 4 degrees C 40 degrees F for sections greater than 1800 mm 72
inches in the least dimension
c.
The minimum requirements may be terminated when temperatures above
10 degrees C 50 degrees F occur during more than half of any 24
hour duration. The temperature of concrete at time of placement
shall not exceed 30 degrees C 90 degrees F.
3.8.3.3
Compressive Strength Tests
**************************************************************************
NOTE: When the same mix design is used for multiple
elements such as slabs, beams, and walls, the design
element type may be specified in lieu of or in
SECTION 03311
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