4. Slump Test
Aim :-
To Determine the Consistency Of Concrete
Principle
The slump test result is a measure of the behavior of a compacted
inverted cone of concrete under the action of gravity. It measures the
consistency or the wetness of concrete.
5. Slump Test
Apparatus
Slump cone : frustum of a cone, 300 mm (12 in) of height. The
base is 200 mm (8in) in diameter and it has a smaller opening
at the top of 100 mm
Scale for measurement,
Temping rod(steel) 15mm diameter, 60cm length.
6. Slump Test
Procedure
The base is placed on a smooth surface and the container is
filled with concrete in three layers, whose workability is to be
tested .
Each layer is temped 25 times with a standard 16 mm (5/8 in)
diameter steel rod, rounded at the end.
When the mold is completely filled with concrete, the top
surface is struck off (leveled with mold top opening) by
means of screening and rolling motion of the temping rod.
The mold must be firmly held against its base during the
entire operation so that it could not move due to the pouring
of concrete and this can be done by means of handles or foot
– rests brazed to the mold.
7. Slump Test
Procedure
Immediately after filling is completed and the concrete is
leveled, the cone is slowly and carefully lifted vertically, an
unsupported concrete will now slump.
The decrease in the height of the center of the slumped
concrete is called slump.
The slump is measured by placing the cone just besides the
slump concrete and the temping rod is placed over the cone
so that it should also come over the area of slumped concrete.
The decrease in height of concrete to that of mould is noted
with scale. (usually measured to the nearest 5 mm (1/4 in).
8. Slump Test
Types Of Slump
The slumped concrete takes various shapes, and
according to the profile of slumped concrete, the slump is
termed as;
Collapse Slump
Shear Slump
True Slump
9. Slump Test
Types Of Slump
Collapse Slump
In a collapse slump the concrete collapses completely.
A collapse slump will generally mean that the mix is too wet or that it
is a high workability mix, for which slump test is not appropriate.
Shear Slump
In a shear slump the top portion of the concrete shears off and slips
sideways. OR
If one-half of the cone slides down an inclined plane, the slump is said
to be a shear slump.
If a shear or collapse slump is achieved, a fresh sample should be
taken and the test is repeated.
If the shear slump persists, as may the case with harsh mixes, this is
an indication of lack of cohesion of the mix.
10. Slump Test
Types Of Slump
True Slump
In a true slump the concrete simply subsides, keeping more or less to
shape
This is the only slump which is used in various tests.
Mixes of stiff consistence have a Zero slump, so that in the rather dry
range no variation can be detected between mixes of different
workability.
However , in a lean mix with a tendency to harshness, a true slump can
easily change to the shear slump type or even to collapse, and widely
different values of slump can be obtained in different samples from the
same mix; thus, the slump test is unreliable for lean mixes.
11. Slump Test
Uses
The slump test is used to ensure uniformity for different batches
of similar concrete under field conditions and to ascertain the
effects of plasticizers on their introduction.
This test is very useful on site as a check on the day-to-day or
hour- to-hour variation in the materials being fed into the mixer.
An increase in slump may mean, for instance, that the moisture
content of aggregate has unexpectedly increases.
Other cause would be a change in the grading of the aggregate,
such as a deficiency of sand.
Too high or too low a slump gives immediate warning and
enables the mixer operator to remedy the situation.
This application of slump test as well as its simplicity, is
responsible for its widespread use.
12. Slump Test
Degree of
workability
Slump (mm) Use for which concrete is suitable
Very low 0 - 25
Very dry mixes; used in road making. Roads
vibrated by power operated machines
Low 25 - 50
Low workability mixes; used for foundations
with light reinforcement. Roads vibrated by
hand operated Machines
Medium 50 - 100
Medium workability mixes; manually
compacted flat slabs using crushed
aggregates. Normal reinforced concrete
manually compacted and heavily reinforced
sections with vibrations
High 100 - 175
High workability concrete; for sections
with congested reinforcement. Not
normally suitable for vibration
>Table : Workability, Slump and Compacting Factor of concrete with 19 or 38 mm (3/4 or 11/2 in) maximum size of aggregate.
14. Flow Test
Aim :-
The flow table test or flow test is a method to determine the
consistence of fresh concrete.
Principle
This test is giving us the ability of concrete to flow under the
gravitational force when poured and compacted within the cone
and suddenly lifted up
15. Flow Test
Equipment
Flow table with a grip and a hinge, 70 cm x 70 cm.
Abrams cone, open at the top and at the bottom - 30 cm high, 17
cm top diameter, 25 cm base diameter
Water bucket and broom for wetting the flow table.
Tamping rod, 60 cm height
Scale for measurement
16. Flow Test
Conducting
The flow table is wetted.
The cone is placed on the flow table and filled with fresh
concrete in two layers, each layer 25 times tamp with
tamping rod.
The cone is lifted, allowing the concrete to flow.
The flow table is then lifted up several centimeters and
then dropped, causing the concrete flow a little bit further.
After this the diameter of the concrete is measured in a 6
different direction and take the average.
20. Compacting Factor Test
Aim
To measure the degree of compaction For the standard
amount of work and thus offer a direct and reasonably
reliable assessment of the workability Of concrete .
Principle
the test require measurement of the weight of the
partially and fully compacted concrete and the ratio the
partially compacted weight to the fully compacted
weight, which is always less than one, is known as
compacted factor .
For the normal range of concrete the compacting factor
lies between 0.8 - 0.92
21. Compacting Factor Test
Apparatus
Trowels
Hand Scoop (15.2 cm long)
Rod of steel or other suitable material
(1.6 cm diameter, 61 cm long rounded
at one end ).
Balance.
22. Compacting Factor Test
Procedure
1) Ensure the apparatus and associated equipment are clean before test
and free from hardened concrete and superfluous water .
2) Weigh the bottom cylinder to nearest 10gm , put it back on the stand
and cover it up with a pair of floats .
3) Gently fill the upper hopper with the sampled concrete to the level of
the rim with use of a scoop .
4) Immediately open the trap door of the upper hopper and allow the
sampled concrete to fall into the middle hopper .
5) Remove the floats on top of the bottom cylinder and open the trap
door of the middle hopper allowing the sampled concrete to fall into
the bottom cylinder .
6) Remove the surplus concrete above the top of the bottom cylinder by
holding a float in each hand and move towards each other to cut off
the concrete across the top of cylinder
23. Compacting Factor Test
7) Wipe clean the outside of cylinder of concrete and weigh to nearest
10gm .
8) Subtract the weight of empty cylinder from the weight of cylinder plus
concrete to obtain the weight of partially compacted concrete .
9) Remove the concrete from the cylinder and refill with sampled
concrete in layers .
10) Compact each layer thoroughly with the standard Compacting Bar to
achieve full compaction .
11) Float off the surplus concrete to top of cylinder and wipe it clean .
12) Weigh the cylinder to nearest 10gm and subtract the weight of empty
cylinder from the weight of cylinder plus concrete to obtain the weight
of fully compacted concrete .
26. VeBe Time Test
Aim
To Measure the workability of Concrete
Principle
It is based on measuring the time (Called VEBE time) needed to transfer the
shape of a concrete mix from a frustum cone to a cylinder (these shapes are
standardized by the apparatus of this test), by vibrating and compacting the
mix. The more VEBE time needed the less workable the mix is. This method
is very useful for stiff mixes.
27. VeBe Time Test
Apparatus
Cylindrical container with diameter = 240
mm, and height = 200 mm
Mold: the same mold used in the slump
test.
Disc : A transparent horizontal disc
attached to a rod which slides vertically
Vibrating Table : 380*260 mm, supported
by four rubber shock absorbers
Tamping Rod
Stop watch
28. VeBe Time Test
Procedure
1) Slump test as described earlier is performed, placing the slump
cone inside the sheet metal cylindrical pot of the consist meter.
2) The glass disc attached to the swivel arm is turn and place on the
top of the concrete in the pot.
3) The electrical vibrator is then switched on and simultaneously a
stop watch started.
4) The vibration is continued till such time as the conical shape of the
concrete disappears and the concrete assume a cylindrical shape.
5) This can be judge by observing the glass disc from the top
disappearance of transparency.
6) Immediately when the concrete fully assume a cylindrical shape,
the stop watch is switched off.
29. VeBe Time Test
7) The time required for the shape of concrete to change from slump
cone shape to cylindrical shape in second is known as Vibe Degree.
8) This method is very suitable for very dry concrete whose slump
value cannot be measure by slump test, but the vibration is too
vigorous for concrete with slump greater than about 50m.
The test fails if VeBe Time is less than 5 seconds .. And the test must be
created when no collapse or shears slump in concrete
31. L-Box Test
Aim
The method aims at investigating the passing ability of SCC.
Principle
It measures the reached height of fresh SCC after passing through the
specified gaps of steel bars and flowing within a defined flow distance.
With this reached height, the passing or blocking behavior of SCC can be
estimated
32. Apparatus
Two types of gates can be
used, one with 3 smooth bars
and one with 2 smooth bars.
The gaps are 41 and 59 mm,
respectively
Suitable tool for ensuring
that the box is level i.e. a
spirit level
Suitable buckets for taking
concrete sample
L Box Test
34. L-Box Test
Procedure
Place the L-box in a stable and level position
Fill the vertical part of the L-box, with the extra adapter mounted, with
12.7 liters of representative fresh SCC
Let the concrete rest in the vertical part for one minute (± 10 seconds).
During this time the concrete will display whether it is stable or not
(segregation).
Lift the sliding gate and let the concrete flow out of the vertical part into
the horizontal part of the L-box.
When the concrete has stopped moving, measure the average distance,
noted as Δh, between the top edge of the box and the concrete that
reached the end of the box, at three positions, one at the centre and two at
each side
35. L-Box Test
Expression Of Results
The passing ratio PL or blocking ratio BL is calculated using equation (2) or
(2’), and expressed in dimensionless to the nearest 0.01
Precision
The passing ratio PL or blocking ratio BL is calculated using equation (2) or
(2’), and expressed in dimensionless to the nearest 0.01
Based on the inter-laboratory test organised in the EU-project “Testing-
SCC” (GRD2- 2000-30024/G6RD-CT-2001-00580) with 2 replicates and 22
operators from 11 laboratories, the precision of the L-box passing or
blocking ratio can be expressed by the following equations
or
where Hmax = 91 mm and H = 150 − Δh
36. L-Box Test
Precision
r = 0.474 – 0.463PL, with R2 = 0.996, when PL ≥ 0.65; and r = 0.18 when PL < 0.65
(3)
or
r = 0.463BL – 0.011, with R2 = 0.996, when BL ≤ 0.35; and r = 0.18 when BL > 0.35
(3’)
and
R = 0.454 – 0.425PL, with R2 = 0.989, when PL ≥ 0.65; and R = 0.18 when PL < 0.65
(4)
or
R = 0.425BL – 0.029, with R2 = 0.996, when BL ≤ 0.35; and R = 0.18 when BL > 0.35
(4’)
where R2 is the square correlation coefficient.
Some values are listed in Table 2 for convenience of use
39. J-Ring Test
Definition
The J-ring test aims at investigating both the filling ability and the passing
ability of SCC. It can also be used to investigate the resistance of SCC to
segregation by comparing test results from two different portions of sample.
The J-ring test measures three parameters: flow spread, flow time T50J
(optional) and blocking step. The J-ring flow spread indicates the restricted
deformability of SCC due to blocking effect of reinforcement bars and the
flow time T50 indicates the rate of deformation within a defined flow
distance. The blocking step quantifies the effect of blocking.
Apparatus
J-ring with the dimensions as shown in Figure 6, where the positions for the
measurement of height differences are also given
Straight rod for aligning the reference line in the measurement, with a length
of about 400 mm and at least one flat side having the flexure less than 1 mm.
41. J-Ring Test
Procedure
Place the cleaned base plate in a stable and level position
Fill the bucket with 6~7 litres of representative fresh SCC and let the sample
stand still for about 1 minute (± 10 seconds).
Under the 1 minute waiting period pre-wet the inner surface of the cone and
the test urface of the base plate using the moist sponge or towel, and place
the cone in the centre on the 200 mm circle of the base plate and put the
weight ring on the top of the cone to keep it in place. (If a heavy cone is used,
or the cone is kept in position by hand no weight ring is needed).
Place the J-ring on the base plate around the cone
Fill the cone with the sample from the bucket without any external
compacting action such as rodding or vibrating. The surplus concrete above
the top of the cone should be struck off, and any concrete remaining on the
base plate should be removed
42. J-Ring Test
Procedure
Check and make sure that the test surface is neither too wet nor too dry. No
dry area on the base plate is allowed and any surplus of the water should be
removed – the moisture state of the plate shall be ‘just wet’.
After a short rest (no more than 30 seconds for cleaning and checking the
moist state of the test surface), lift the cone perpendicular to the base plate in
a single movement, in such a manner that the concrete is allowed to flow out
freely without obstruction from the cone, and start the stopwatch the
moment the cone loose the contact with the base plate
Stop the stopwatch when the front of the concrete first touches the circle of
diameter 500 mm. The stopwatch reading is recorded as the T50J value. The
test is completed when the concrete flow has ceased.
lay the straight rod with the flat side on the top side of the J-ring and
measure the relative height differences between the lower edge of the
straight rod and the concrete surface at the central position (Δh0) and at
the four positions outside the J-ring, two (Δhx1, Δhx2) in the x-direction
and the other two (Δhy1, Δhy2) in the y-direction (perpendicular to x)
43. J-Ring Test
Procedure
Measure the largest diameter of the flow spread, dmax, and the one
perpendicular to it, dperp, using the ruler (reading to nearest 5 mm). Care
should be taken to prevent the ruler from bending
NOTE For non-circular concrete spreads the x-direction is that of the largest
spread diameter
Expression Of Results
The J-ring flow spread SJ is the average of diameters dmax and dperp, as
shown in Equation (6). SJ is expressed in mm to the nearest 5 mm
44. J-Ring Test
Expression Of Results
The J-ring flow time T50J is the period between the moment the cone leaves
the base plate and SCC first touches the circle of diameter 500 mm. T50J is
expressed in seconds to the nearest 1/10 seconds
The J-ring blocking step BJ is calculated using equation (7) and expressed in
mm to the nearest 1 mm.
45. J-Ring Test
Precisions
Based on the inter-laboratory test organised in the EU-project “Testing-SCC”
(GRD2- 2000-30024/G6RD-CT-2001-00580) with 2 replicates and 16
operators from 8 laboratories, the values of repeatability and reproducibility
of the J-ring flow spread and flow time T50J are listed in Table 6
46.
47. V-Funnel Test
Definition
The V-funnel flow time is the period a defined volume of SCC needs to pass a
narrow opening and gives an indication of the filling ability of SCC provided
that blocking and/or segregation do not take place; the flow time of the V-
funnel test is to some degree related to the plastic viscosity.
Apparatus
V-funnel, as shown in Figure 7, made of steel, with a flat, horizontal top and
placed on vertical supports, and with a momentary releasable, watertight
opening gate
Stopwatch with the accuracy of 0.1 second
for recording the flow time
Straightedge for levelling the concrete
Buckets with a capacity of 12∼14 litres
for taking concrete sample
Moist sponge or towel for wetting
the inner surface of the V-funnel
48. V-Funnel Test
Procedure
Place the cleaned V-funnel vertically on a stable and flat ground, with the top
opening horizontally positioned
Wet the interior of the funnel with the moist sponge or towel and remove the
surplus of water, e.g. through the opening. The inner side of the funnel should
be ‘just wet’.
Close the gate and place a bucket under it in order to retain the concrete to be
passed
Fill the funnel completely with a representative sample of SCC without
applying any compaction or rodding
Remove any surplus of concrete from the top of the funnel using the
straightedge.
Open the gate after a waiting period of (10 ± 2) seconds. Start the stopwatch at
the same moment the gate opens
49. V-Funnel Test
Procedure
Look inside the funnel and stop the time at the moment when clear space is
visible through the opening of the funnel. The stopwatch reading is recorded
as the V-funnel flow time, noted as tV
Do not touch or move the V-funnel until it is empty
Expression Of Results
The V-funnel flow time tV is the period from releasing the gate until first light
enters the opening, expressed to the nearest 0.1 second
50. V-Funnel Test
Expression Of Results
Based on the inter-laboratory test organised in the EU-project “Testing-SCC”
(GRD2- 2000-30024/G6RD-CT-2001-00580) with 2 replicates and 20 operators
from 10 laboratories, the precision of the V-funnel flow time can be expressed
by the following equations
the precision of the V-funnel flow time can be expressed by the following
equations:
r = 0.335 tV – 0.62, with R2 = 0.823, when 3 ≤ tV ≤ 15; and r = 4.4 when tV > 15 (8)
and
R = 0.502 tV – 0.943, with R2 = 0.984, when 3 ≤ tV ≤ 15; and R = 6.6 when tV > 15 (9)
where R2 is the square correlation coefficient.
Some values are listed in Table 5 for convenience of use.
53. Orimet Test
Definition
The Orimet flow time is the period a defined volume of SCC needs to pass a
narrow opening (a tube narrowed by an orifice). The flow time of the Orimet
test is to some degree related to the plastic viscosity
Apparatus
Orimet, made of steel, with the tube of a length of 600 mm and an inner
diameter of 120 mm. The orifice, which narrows the opening of the tube and
shears SCC, is interchangeable; its diameter can be chosen according to the
mixture composition and the criteria on SCC. Figure 8 shows the filling of the
Orimet with a bucket
Stopwatch with the accuracy of 0.1 second for recording the flow time
Straightedge for levelling the concrete
Buckets with a capacity of 10∼12 litres for taking concrete sample
Moist sponge or towel for wetting the inner surface of the Orimet
55. Orimet Test
Procedure
Place the cleaned Orimet vertically on a stable and flat ground, with the top
opening horizontally positioned and check whether the tripod is completely
extended
Wet the interior of the Orimet with the moist sponge or towel and remove the
surplus of water, e.g. through the opening. The inner side of the Orimet
should be ‘just wet’.
Close the gate and place a bucket under it in order to retain the concrete to be
passed
Fill the Orimet completely with a representative sample of SCC without
applying any compaction or rodding
Remove any surplus of concrete from the top of the Orimet using the
straightedge
Open the gate after a waiting period of (10 ± 2) seconds. Start the stopwatch at
the same moment the gate opens
56. Orimet Test
Procedure
Look inside the Orimet and stop the time at the moment when clear space is
visible through the opening of the Orimet. The stopwatch reading is recorded
as the Orimet flow time, noted as tO
Expression Of Results
The Orimet flow time tO is the period from releasing the gate until first light
enters the opening, expressed to the nearest 0.1 second
Based on the inter-laboratory test organised in the EU-project “Testing-SCC”
(GRD2- 2000-30024/G6RD-CT-2001-00580) with 2 replicates and 20 operators
from 10 laboratories, the precision of the Orimet flow time (with the orifice 70
mm) can be expressed by the following equations
57. Orimet Test
Expression Of Results
r = 0.433 tO – 0.594, with R2 = 0.996, when 3 ≤ tO ≤ 15; and r = 6.6 when tO > 15
(10)
and
R = 0.472 tO – 0.28, with R2 = 0.947, when 3 ≤ tO ≤ 15; and R = 6.8 when tO > 15 (11)
where R2 is the square correlation coefficient.
Some values are listed in Table 6 for convenience of use.