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Unformatted text preview: s permitted as admixtures
shall have established merit
any specific quality
of the concrete without
causing deleterious effects.
for mixing concrete, g-rout, or mortar, and also for
washing the aggregates and Curing concrete, shall be clean and free from
of acid, alkali, silt, oil, organic matter,.or
3.4 Aggregates 3.4.1 Agbqegates for concrete shall conform to @IS: 383-1952 or tIS: 515.
3.4.2 The maximum
size of coarse aggregate,
biggest square hole through which not less than 95 percent of the aggregate shall pass shall be as large as can be ‘used practicably
and economically under given conditions,
but shall be not -larger than any one of
the following :
the narrowest dimension
between the faces of forms,
b) one-third the depth of any slab,
of the clear space between reinforcement
of the narrowest
which the concrete
shall have to be passed.
shall be any of the following:
Mild steel and high tensile steel bars and hard-drawn
conforming to: IS: 432-1953,
steel sections conforming
to 5 IS : 226-1955,
Cold twisted steel bars complying
with the requirements
of Appendix A of ?i IS: 456-1957, and
Such other reinforcement
as may bc proved suitable, having regard
to the yield point stress, ductility,
and other essential
of the completed
produced in readiness for use in reinforced concrete. 3.5.1 Mill scale and rust scale, if any, shall be removed
inforcemen t before 3.6 Storaee from the re- use. of Materials 3.6.1 Cement shall be stored in a damp proof place.
storage facilities shall be such that no cement is stored before use for more
than 120 days counted from the date of despatch by the manufacturer.
B Second r&irion in 1970.
h 196+. 8 IS : 457 - 1957
Cement stored beyond 120 days but not exceeding 180 days shall be tested
and rejected if found defective in any way. Cement stored beyond 180
Cement shall be ch:ckLd
days shall not be used for major construction.
on the job for contamination or partial setting due to exposure to moisture
3.6.2 Aggregates shall. be stored and handled in such a manper as to
prevent the intermingling of various sizes of aggregates required.separately
for grading purposes. No foreign matter shall be allowed to be mixed up
with the aggregates. Stockpiles shall be built in layers of uniform thickness.
rusting of steel. shall be stored in such a manner as to minimize 4. CONCRETE
4.1 General - The concrete used in dams and other structures may vary
in character from mass concrete having a maximum size of aggregate from 10 cm ( preferahly 15 cm ) to 23 cm [ or 4 in ( ljreferably 6 in ) to 9 in I
and a cement content ran...
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- Fall '13