inches at the point of placement. For other slabs, slump of lightweight
concrete shall not exceed 100 mm 4 inches at point of placement.]
1.8.5
Concrete Temperature
The temperature of the concrete as delivered shall not exceed 32 degrees C
90 degrees F. When the ambient temperature during placing is 5 degrees C
40 degrees F or less, or is expected to be at any time within 6 hours after
placing, the temperature of the concrete as delivered shall be between 12
and 25 degrees C 55 and 75 degrees F.
1.8.6
Size of Coarse Aggregate
The largest feasible nominal maximum size aggregate (NMSA) specified in
paragraph AGGREGATES shall be used in each placement. However, nominal
maximum size of aggregate shall not exceed any of the following:
three-fourths of the minimum cover for reinforcing bars, three-fourths of
the minimum clear spacing between reinforcing bars, one-fifth of the
narrowest dimension between sides of forms, or one-third of the thickness
of slabs or toppings.
1.8.7
Special Properties and Products
**************************************************************************
NOTE: If the use of a particular type of admixture
is required for certain parts of the structure, this
paragraph should be revised accordingly.
**************************************************************************
Concrete may contain admixtures other than air entraining agents, such as
water reducers, superplasticizers, or set retarding agents to provide
special properties to the concrete, if specified or approved. Any of these
materials to be used on the project shall be used in the mix design studies.
1.8.8
Lightweight Aggregate Structural Concrete
**************************************************************************
NOTE: Retain this paragraph when lightweight
aggregate structural concrete is required. Use
bracketed alternate strength inserts (compressive or
splitting tensile strength) as appropriate.
Correlate strength versus unit weight requirements
as determined from table in ASTM C 330, and as
determined by consultation with local producers.
Remove last sentence when floor fill is not required.
**************************************************************************
Lightweight aggregate structural concrete shall conform to the requirements
specified for normal weight concrete except as specified herein.
[Specified compressive strength shall be at least [_____] at 28 days,]
[Specified splitting tensile strength determined in accordance with ASTM C
496/C 496M shall be at least [_____] at 28 days,] as determined by test
last 21 days. Air-dry unit weight shall be not over [_____] at 28 days as
determined by ASTM C 567. However, fresh unit weight shall be used for
acceptance during concreting, using a correlation factor between the two
types of unit weight as determined during mixture design studies.
Lightweight aggregate structural concrete floor fill shall have a 28-day
compressive strength of at least 17.3 MPa 2500 psi and an air-dry unit
SECTION 03300A
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