Objective

To determine the workability of concrete mix.

Apparatus used:

Slump cone, Tamping rod, Trowel, Measuring jar, Weighing scale, Measuring scale, Tray etc.

 Description Slump Test:
It measures the consistency and workability of fresh concrete before it sets.
Workabilty of concrete:
Workabilty is the relative ease with which concrete can be mixed transported, moulded and compacted.
Consistency of concrete:
It is the amount of water or wetness present in the concrete.

STEP  1 

 Find the volume of the cone from its dimensions ie, by measuring its height and diameter.

Volume of slump cone(frustrum) =

¹⁄₃ πR²H - ¹⁄₃ πr²h

H = 60cm

R = 10cm

h = 30cm

r = 5cm

Volume of slump cone =

      

x 10^-3m³

   

✔

✘

STEP    2 

 Measure required quantity of water, coarse, fine aggregate and cement based on mix design.

Mix proportion is = 1 : 2.7 : 4.2

Water Cement ratio assumed is = 0.43

Cement content = ^Cement⁄_{Cement + C. A. + F. A.}(Density × Volume × 1.52)

Cement content =

Cement content = 1.6kg

kg    

✔

✘

Quantity of fine aggregate = ^{F. A.}⁄_{Cement + C. A. + F. A.}(Density × Volume × 1.52)

Quantity of fine aggregate =

Quantity of fine aggregate = 4.3kg

kg    

✔

✘

Quantity of coarse aggregate = ^{C. A.}⁄_{Cement + C. A. + F. A.}(Density × Volume × 1.52)

Quantity of coarse aggregate =

Quantity of coarse aggregate = 6.7kg

kg    

✔

✘

Water content = 0.43 x Cement content

Water content = 0.43 x 1.6 = 0.67Liter

0.000 g

g

Quantity of cement = 1.6kg

Quantity of fine aggregate = 4.3kg

Quantity of coarse aggregate = 6.7kg

Volume of water = 0.67 l

1.6kg Cement

4.3kg Fine aggregate

6.7kg Coarse aggregate

STEP   3 

  Dry mix the materials properly.

STEP   4 

  Add measured quantity of water, mix it thoroughly and uniformly.

STEP   5 

 Place the cleaned slump cone on a horizontal slump base.

STEP   6 

 Fill the mould in four layers, each layer is tamped 25 times by a tamping rod.

STEP   7 

 Remove extra concrete with the trowel and tamping rod.

STEP   8 

 Remove the mould from the concrete immediately by raising it slowly in vertical direction.

STEP   9 

 Note down the slump by keeping slump cone mould as reference.

Slump value = 30 - 12 = 18cm

 

Observation

Water cement ratio assumed	0.43
Mix proportion	1 : 2.7 : 4.2
Quantity of cement	1.6kg
Quantity of fine aggregate	4.3kg
Quantity of coarse aggregate	6.7kg
Volume of water	0.67l
Slump value	18cm

Inference:

Degree of workability is high.