Vee-Bee Consistometer test

The main objective of Vee-Bee test is to determine the workability of the freshly mixed concrete. The Vee-Bee test gives an indication about the mobility and the compactibility aspect of the freshly mixed concrete.

Vee-bee test carries out the relative effort measurement to change the mass of the concrete from a definite shape to the other. That is, as per the test, from the conical shape to the cylindrical shape by undergoing vibration process.

The measurement of the effort is done by time measurement in seconds. The amount of work measured in seconds is called as the remolding effort. The time required for the complete remolding is a measure of the workability and is expressed in the Vee-Bee seconds.

AIM: To determine the consistency of concrete using a Vee-Bee Consistometer.

APPARATUS:

1.   vibrator table resting upon elastic supports,

2.   metal pot,

3.   sheet metal cone, open at both ends,

4.   Trowels,

5.   Hand scoop

6.   Standard tamping rod (1.6 cm diameter, 61 cm long rounded at one end)

FIGURE:

THEORY: 

The Vee-Bee test apparatus consist of a Vee-Bee consistometer as per IS: 119 – 1959, as shown in the figure. The apparatus consists of a vibrating table which is supported and mounted on elastic supports. It also consists of a sheet metal slump cone, a weighing balance, cylindrical container, a standard iron tamping rod and trowels.

The vibrating table as shown in figure-1 has a dimension of 380mm length and a width of 260mm. At a height of 305mm, it is supported on a rubber shock absorber above the level of floor.

A vibrator is provided under the table. This vibrator is operated electrically. The whole mentioned assembly is mounted on a base as shown above which is in turn resting on rubber supports three in number.

The sheet metal slump cone mold has opening at both ends and is placed in a cylindrical container as shown in figure-1. The cylinder container is mounted over the vibration table with the help of wing nuts.

PROCEDURE:

1.   Clean the slump cone & cylinder well.

2.   Prepare the concrete of a nominal mix with an initial water / cement ratio = 0.5.

3.   Place the slump cone inside the cylinder & fill it in layers.

4.   Remove the slump cone & note the subsidence of concrete with the help of glass plate rider.

5.   Vibrate the table till the concrete is completely remoulded. When the vibration is started, start the stopwatch.

6.   Note the time taken for the complete transformation from conical shape to cylindrical form. 

OBSERVATION:

The time required for the shape of concrete to change from slump cone shape to cylindrical shape in seconds is known as Vee Bee Degree.