No. of tests (1)
Modification factor
for standard deviation
less than 15
See Note
15
1.16
20
1.08
25
1.03
30 or more
1.00
_____________________________________________________
(1) Interpolate for intermediate numbers of tests.
Note: When a concrete production facility does not have field strength test
records for calculation of standard deviation or the number of tests is
less than 15, the required average strength shall be specified strength
plus 3.5 MPa 500 psi.
1.11
STORAGE OF MATERIALS
Cement and pozzolan shall be stored in weathertight buildings, bins, or
silos which will exclude moisture and contaminants. Cement shall be
furnished in suitable bags used for packaging cements. Labeling of
packages shall clearly define contents, manufacturer, batch identification,
etc. Aggregate stockpiles shall be arranged and used in a manner to avoid
excessive segregation and to prevent contamination with other materials or
with other sizes of aggregates. Reinforcing bars and accessories shall be
stored in such a manner as to avoid contamination and deterioration.
Admixtures which have been in storage at the project site for longer than
six months or which have been subjected to freezing shall not be used
unless retested and proven to meet the specified requirements. Epoxy shall
be stored in accordance with the manufacturer's recommendations.
1.12
WEATHER LIMITATIONS
Concrete, mortar, and epoxy adhesives shall not be placed when weather
conditions detrimentally affect the quality of the finished product. No
concrete or mortar shall be placed when the air temperature is below 5
degrees C 40 degrees F in the shade. When air temperature is likely to
exceed 35 degrees C 90 degrees F, concrete and mortar shall have a
temperature not exceeding 35 degrees C 90 degrees F when deposited, and the
surface of the placed concrete shall be kept damp with a water fog until
the approved curing medium is applied. Materials proposed for use in the
work shall not be produced and placed during periods of rain or other
precipitation. Material placements shall be stopped and all in-place
material shall be protected from exposure during periods of rain or other
PART 2
PRODUCTS
2.1
MATERIALS
Materials, physical and chemical properties, and composition of new
concrete shall match that of existing concrete to be repaired, unless
samples and testing determine that existing mixtures and materials are
faulty or non-performing.
2.1.1
Admixtures
Air entraining admixtures shall conform to ASTM C 260, water-reducing or
SECTION 03900
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