Procedure for determination of workability of concrete by slump test
AIM:
To determine the workability of concrete mix of given proportion by slump test.
APPARATUS:
Iron Pan to mix concrete, weighing machine, trowel, slump cone, scale and tamping rod
DESCRIPTION:
The slump cone is a hollow frustum made of thin steel sheet with internal dimensions as, the top diameter 10cm, the bottom diameter 20 cm, and height 30 cm .It stands on a plane non- porous surface. To facilitate vertical lifting from molded concrete it is provided with a suitable guide attachment and suitable foot places and handles. The tamping rod is 16mm dia 60cm long and is bullet pointed at the lower end.
THEORY: Unsupported concrete, when it is fresh, will flow to the sides and a sinking in height will take place. This vertical settlement is called slump. Slump is a measure indicating the workability of cement concrete and also slump gives an idea of W/C ratio needed for concrete to be used for different works. Slump increases with W/C ratio. A concrete is said to be workable if it can be easily mixed and easily placed compacted and easily finished.
PROCEDURE:
Mixes are prepared with W/C. ratio 0.4, 0.5, 0.55 and 0.6. For each mix take C.A. = 10 kg, F.A. = 5 kg and Cement = 2.5 kg.
1) Mix the dry constituents to get a uniform color and then add water.
2) The internal surface of the mould is to be thoroughly cleaned and place on a smooth, horizontal, rigid and non-absorbent surfaceng
3) Place the mixed concrete in the cleaned slump cone in 4 layers each approximately ¼ in height of the mould . Tamp each layer 25 times with tamping rod. 4) Remove the cone immediately, rising it slowly and carefully in the vertical direction. 5) As soon as the concrete settlement comes to a stop, measure the subsidence of the concrete in mm, which gives the slump. OBSERVATIONS: S. No. W/C Ratio Slump Type of Slump 0.45, 0.5 , 0.55 , 0.6 5, 0.65
SPECIFICATIONS:
As per I.S: 456 the degree of workability is classified as follows.
Degree of workability Slump
Very low 0mm to 25mm
Low 25mm to 50mm
Medium 50 mm to 100 mm.
High 100 mm to 175 mm
AIM:
To determine the workability of concrete mix of given proportion by slump test.
APPARATUS:
Iron Pan to mix concrete, weighing machine, trowel, slump cone, scale and tamping rod
DESCRIPTION:
The slump cone is a hollow frustum made of thin steel sheet with internal dimensions as, the top diameter 10cm, the bottom diameter 20 cm, and height 30 cm .It stands on a plane non- porous surface. To facilitate vertical lifting from molded concrete it is provided with a suitable guide attachment and suitable foot places and handles. The tamping rod is 16mm dia 60cm long and is bullet pointed at the lower end.
THEORY: Unsupported concrete, when it is fresh, will flow to the sides and a sinking in height will take place. This vertical settlement is called slump. Slump is a measure indicating the workability of cement concrete and also slump gives an idea of W/C ratio needed for concrete to be used for different works. Slump increases with W/C ratio. A concrete is said to be workable if it can be easily mixed and easily placed compacted and easily finished.
PROCEDURE:
Mixes are prepared with W/C. ratio 0.4, 0.5, 0.55 and 0.6. For each mix take C.A. = 10 kg, F.A. = 5 kg and Cement = 2.5 kg.
1) Mix the dry constituents to get a uniform color and then add water.
2) The internal surface of the mould is to be thoroughly cleaned and place on a smooth, horizontal, rigid and non-absorbent surfaceng
3) Place the mixed concrete in the cleaned slump cone in 4 layers each approximately ¼ in height of the mould . Tamp each layer 25 times with tamping rod. 4) Remove the cone immediately, rising it slowly and carefully in the vertical direction. 5) As soon as the concrete settlement comes to a stop, measure the subsidence of the concrete in mm, which gives the slump. OBSERVATIONS: S. No. W/C Ratio Slump Type of Slump 0.45, 0.5 , 0.55 , 0.6 5, 0.65
SPECIFICATIONS:
As per I.S: 456 the degree of workability is classified as follows.
Degree of workability Slump
Very low 0mm to 25mm
Low 25mm to 50mm
Medium 50 mm to 100 mm.
High 100 mm to 175 mm
