2.1 MATERIALS
.1 Cement Type: Type I Normal, and type V (Sulphate Resistant), Type IV low heat
of hydration, as per E.S.S. 373, E.S.S. 541, E.S.S. 583, E.S.S. 2149, ACI 318,
ASTM C 150, ASTM C 595, and ASTM C 845 .
.2 It is anticipated that one or more supplementary cementing materials will have to
be used in the concrete to produce a mix with acceptable fresh and hardened
concrete properties and acceptable thermal characteristics during hardening. The
materials will be one or more of the following
a) Granulated blast furnace slag,
b) Fly-ash,
c) Silica fume.
2.2 Aggregates
.
2.2.1 Nominal Size of Coarse Aggregate: 5 mm to 20 mm. Use pea gravel (5
mm to 10 mm) where concentration of reinforcement requires the use of a
smaller diameter aggregate, as per ACI 318 and ASTM C 33.
2.2.2 Fine Aggregate: Natural and conforming to ASTM C33 Standard
Specification for Concrete Aggregates modulus shall be 2.9 to 3.1.
Quality Control of Supplementary Cementing Materials: Test data to the
satisfaction of the consultant shall be obtained from each delivery and this
data shall be supplied to the independent inspection company prior to its
use. The mode of communication between the concrete supplier and the
independent inspection company shall be agreed prior to the supply of
any of these materials.
.
3.0 Admixtures
.
3.1 Admixtures: Air entraining agents, water reducing admixtures, or
superplasticizers that have been tested in accordance with ACI and
ASTM requirements and which have been successfully used in Cairo.
Admixtures shall conform to E.S.S. 1899, ACI 318, ASTM C 260, ASTM
C 494, ASTM C 1017, ASTM C 618, ASTM C 989, ASTM C 1240
COOLING OF CONCRETE
.1 In summer months the cooling of high strength concrete is required to control the
generation of heat in the concrete and to meet the requirements of this
specification. Experience indicates that the addition of ice to high strength
concrete is not adequate to meet the maximum concrete placing temperature and that other methods such as liquid nitrogen cooling
are required. The concrete supplier shall provide full details to the Consultant of
the concrete cooling method proposed for use and shall demonstrate to the
satisfaction of the Consultant that the proposed method is effective.
CURING
.1 Cure all high strength concrete by the application of curing compound.
.2 Apply curing compound to all surfaces as soon as the members are stripped.
.3 During hot weather, provide continuous water curing, in addition to curing
compound, for a period of approximately 48 hours or such time as is required
until the temperature of concrete begins to fall. In this case, water curing is used
to prevent excessive rise in temperature
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