In this article, we will discuss the consistency test of cement.
A less amount of water is needed to determine the chemical reaction between water and cement to make a thick paste is known as the consistency of cement.
2. Consistency test of Cement
a) Weighing balance of 1000 gm with 1gm accuracy.
b) Vicat apparatus
c) Vicat Mould
d) Measuring Cylinder 200ml
e) Glass plate
It consists of a metal frame to which is attached a movable rod weighting 300g along with a cap and attachment. And having diameter and length is 10mm and 50 mm respectively.
The movable rod is given with a releasing pin to let the rod free and is fixed with an indicator to give readings on a vertical scale which is divided from 0 to 40 mm in either direction which provides the penetration.
The Vicat mould is in the shape of a cylinder. It can be divided into two particular halves and is kept on a non-porous plate. There are the following three parts:
(i). Square needle: It is used for the intial setting time test.
(ii). Plunger: It is used for consistency tests.
(iii). Annular collar: It is used for final setting time.
The whole apparatus is made of gunmetal, aluminium or steel.
a. Take 400 grams of cement.
b. Taking that consistency must be 29.5% since we are taking OPC cement. This is a trial and error method done on OPC Cement.
c. Take 29.5% of the water that means (400 x 29.5% )=118 gm of water.
d. Mix the water with cement and wait for the cement paste.
e. Now, fill the Vicat mould with the cement paste.
f. Ensure to compact the paste well after filling the mould
g. Now fill the compact paste to the top of the mould. Remove the excess paste with a towel.
h. Now separate the plunger and permit it to penetrate through the paste.
i. Note reading on the Vicat measuring scale.
j. Standard consistency % = Weight of water added/ Weight of cement * 100%.
The standard consistency of cement should lie between 25-35%. To make a mix of cement paste 25-35% water by weight of cement is added to gain a good consistency of cement by using consistency test of cement.
|Read More: Initial and Final Setting Time of Cement|
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