GENERAL AND PARTICULAR SPECIFICATIONS OF ... - UNDP

SPECIFICATIONS
CONCRETE WORK
The total sodium chloride content of any materials
used for making concrete shall be less than :
- For mass concrete .............. 1.5 percent
- For reinforced concrete ........ 0.7 percent
Expressed as a percentage, by weight of the cement. In
calculations made under the provisions of this clause,
any chloride, other than sodium chloride in the materials
shall be converted to the equivalent of sodium chloride
and be added to the amount of sodium chloride. The
sulphate content shall not exceed 0.03 percent by weight
of the cement.
C 5
C 5.01
PROPORTIONS
General
After the materials provided by the Contractor have been
accepted for the works, the proportions and equivalent
batch weights shall be determined which will produce
concrete having not less than the strength required.
C 5.02
Trial Mixes
The actual proportions shall be determined on the basis
trial mixes made by the Contractor and conducted with the
content being determined by means of yield test in
accordance with American Society for Testing Material
(ASTM) Designation (C-138). The proportions will be such
as to required (within a tolerance of plus or minus one
(1) percent, the cement content shown in Table I as the
minimum cement content, provided, however, that if the
materials supplied by the Contractor are of such a nature
or are so graded that proportions based on the minimum
cement content cannot be used without exceeding the
maximum allowable water content specified in Table I, the
proportions will be adjusted so as to require the least
amount of cement which will produce concrete of the
required plasticity and work- ability without exceeding
such maximum allowable water content. No additional
compensation will be made for the increase in quantity of
cement required.
C 5.03
Contents
The mixes required will be designated in kilograms of
fine and coarse aggregate exclusive of free water, per
sack (50 Kilograms) of cement and in liters of total
mixing water per sack of cement on the basis of the
required amount of cement per cubic meter of concrete.
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