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Unformatted text preview: the detachable cable
connected to the vibrometer
and a control switc!).
the apparatus under operation is given in Fig. 2.
A-3.1 A slump test as described in Appendix G of *IS: 456-1957 is perThe glass
formed in the sheet metal cylindrical
pot of the consistometer. 2 4 6 VEE-BEE 8 IO DEGREES FIG.3 RELATION BETWEEN SLUMP IN CM AND VEE-BEE DEGREES
*Second revision in 1964. 37 I IS : 457 - 1957
disc attached to the swivel arm is moved and is placed just on top of the
slump cone in the pot and before the cone is lifted up the position of the
concrete cone is noted by adjusting
the glass disc attached
to the swivel
? he cone is then lifted up and the slump is noted on the graduated
rod by lowering the glass disc on top of the concrete cone.
vibrator is then switched on and the concrete is allowed to spread out in
until the whole concrete surface uniformly adheres to the glass disc as indicated in Fig. 2 and the time taken
for this to be attained is noted with a stop-watch.
The time is recorded in
‘i-4. RESULT A-4.1 The consistency
of the concrete is expressed
which are equal to the time in seconds under A-3.1.
A-4.2 The required
scale given in Table II. is obtained on the basis in Vee-Bee
of the degrees consistency A-4.2.1 The curve in Fig. 3 indicates the relationship
in cm and the degrees covered by the consistency
scale given in Table Il.
M&t earth Very dry II NUMDEX OP VEE-UER 20 to IS to 10 to 7 ta c Plastic 5 to 4 to 3 Semi-fluid 3 to 2 to 1 Fluid More fluid
than 1 SCALE
CHAR.XTERISTICS DEGP.EES 40 to 25 to 20 IO CONSISTENCY Particles 01 coarse aggregate in the concrete are
adhesive, but concrete does not clot.
Concrete has the consistency of yery stiff porridge, forms a stiff mound when dumped, and
barely tends to shake or roll itself to form an
almust horizontal surface when conveyed for
a long time in, say, a wheel-barrow
Concrete has the consistency of stiff porridge,
forms a mound when dumped, and shakes or
rolls itself to form a horizontal surface when
conveyed for a long time in, say, a whcclbarrow.
Co!xrcte can be shaped into a ball bctwccn the
palms of the hands an? adheres to the skin.
Concrete cannot be rolled int(l a haK1 between
the palms of the hands, but spreads out even
though slowly and without affecting the cohesion of the constituents
so that segregation
does not occur.
Concrete spreads uut rapidly and segrcgatlon
takes place. 38 JS : 457 - 1957 APPENDIX I3 ( Clause 7.5.2 j
B-l. OF SECURING HARDENED SPECIMENS
CONCRETE FROM THE STRUCTURE OF SCOPE B-l.1 This method covers the procedure
testing specimens of hardened concrete from structures
B-2. PRECAUTIONS I B-2.1 A specimen to be tested for stretlgth shall not be removed from
until the concrete has become hard enough to permit its
removal without disturbing
the bond bet...
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- Fall '13