Normal consistency test

This was done at Koya university Faculty of Engineering

1. Koya University
Faculty of Engineering
Civil Department - 2
nd
Stage
Concrete Technology

Test no: 2


Normal Consistency of Hydraulic Cement


Student Name: Muhammad Saleem Asaad
Group: B
Expr Date: 15-11-2015
Submission Date: 29-11-2015

2. OBJECTIVES

The objective of conducting consistency test is to find the amount of
water to be added to cement to get a paste of normal consistency i.e.
the paste of certain standard solidity which is used to fix the quality
of water to be mixed in cement before performing tests for;
Setting time of cement.
Soundness of cement.

3. APPARATUS

1. Vicat apparatus with 10mm plunger as shown in Fig.2-1
2. Sensitive Balance
3. Graduated glass cylinder
4. Glass plate with adequate dimension for mixing water and paste.
5. Small trowel
6. Stopwatch.

4. TEST PROCEDURE

Weight out 650g of cement and place it on the mixing plate.
Form a crater in the center and add a measured quantity of water
(take 169ml for the first batch 26%).
Turn the material at the outer edge into the center within 30 sec.
of time by the aid of the trowel.
After an additional interval of 30 sec. for absorption of water,
complete the process by continuous vigorous mixing. Squeeze and
kneading with hands for (1.5 min.).
With the hands quickly form this paste into a ball, complete the
process by tossing the ball six times from one hand to the other hand,
keeping the hands about 6 in. (15 cm) apart.
Press the ball, resting in the palm of one hand, into the large end
of the conical ring of Vicat apparatus, which held by the other hand.
Fill up the conical ring and remove the excess at the large end by
a single movement of the palm of the hand.
Place the ring on its large end on a glass plate and slice off excess
paste at the smaller end at the top of the ring by single oblique stroke
of a sharp edged
Trowel held at a slight angle with the top of the ring, and smooth the
top if necessary, but never compress the paste during these
operations.
Place the ring with the paste under the rod of the Vicat apparatus,
bring the plunger in contact with the surface of the paste, and set the
scale to read zero or read the initial reading. This must not exceed 30
seconds after completion of mixing.
Release the plunger immediately.
The apparatus shall be free of all vibrations during the test.

5. The paste shall be of normal consistency when the rod settles to
a point (10 ± 1 mm) below the original surface in 30 sec. after being
released.
Make trial pastes with varying percentages of water until the
normal consistency is obtained. Make each trial with fresh cement.






Figure1: Vicat Apparatus for Consistency test of Cement Paste

7. Discussion