CONSISTENCY
The basic aim is to find out the water content required to produce a cement paste of standard consistency as specified by the IS: 4031 (Part 4) – 1988. The principle is that standard consistency of cement is that consistency at which the Vicat plunger penetrates to a point 5-7mm from the bottom of Vicat mould.
Apparatus – Vicat apparatus conforming to IS: 5513 – 1976, Balance, whose permissible variation at a load of 1000g should be +1.0g, Gauging trowel conforming to IS: 10086 – 1982.
Procedure to determine consistency of cement
i) Weigh approximately 400g of cement and mix it with a weighed quantity of water. The time of gauging should be between 3 to 5 minutes.
ii) Fill the Vicat mould with paste and level it with a trowel.
iii) Lower the plunger gently till it touches the cement surface.
iv) Release the plunger allowing it to sink into the paste.
v) Note the reading on the gauge.
vi) Repeat the above procedure taking fresh samples of cement and different quantities of water until the reading on the gauge is 5 to 7mm.
Reporting of Results
Express the amount of water as a percentage of the weight of dry cement to the first place of decimal.
If you have a query, you can ask a question here.
So what if we take more or less than 400gm of cement.we took 500gm & the result was good
Actually there is no upper limit to the amount of cement taken .. About 400gm is enough to fill the Vicat mould so the extra cement you are using will remain unused….
actually the container used for testing the consistency of cement in which the mix cement is put into is of standard size 400 or 500 grms
what is the size of needle used for pnetrarion
1mm diameter and 50mm in length…
10 mm dia of the plunger used in the vicat apparatus
10mm
it should 5mm above the bottom of the mould.
how construction industry can improve its stance on green tachnology and sustainable design in leu with concrete and other construction materials.
1 sq. mm. area
why we find out consistency of cement,what is the use in design mix,for my knowledge it is only find out for checking of cement,or other please clear my confusion
can i mix the cement by hand, or only by trowel?
actually consistency means howmuch water shouldbe added with cement to make a standard paste of cement. And we find consistency of cement b’coz in many other experiment of our department we need it, not just testing or checking of cement.
What does “standard paste of cement” means? How will we know that how much water is required to make that standard paste?
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i have some quistion..1-if we do this test three time or more why the results are change?
2-whats the significance of this test ?
3-whats the effect of temperature and relative humidity on the test results?
pala. 1.The results are changed because as you increase the amount of water added you also increase the consistency. 2. The significance is that in mix design water to cement ratio is crucial in attaining desired strengths. This test goes hand in hand along with other tests preformed on ingredients that compose a mix design. its good to know the amount of water needed to create the cement paste that will be needed to coat aggregates in your mix, without exceeding a safe w/c ratio. 3. Temperature will affect setting time higher temperatures equal less setting times and vice versa. i believe the test should be done at a temperature that is relatively close to the temperature in which the concrete application will be preformed.
Hope this helps.
what is the result of consistency test of cement?
It depends on the percentage of water u add… generally it is about 30-40 % for conventional concrete
How we can write the reportes for this consistency paste?
How can l explain to students without this apparatus in an institute?
If we have to conduct consistency test for fly ash or any other ash, what will be the consistency limit and how to check it??
Is it normal consistency of cement depends upon the grades of cement ?
how to write the conclusion for this test?
it is given that normal consist of cement paste should be between 26%-33%,then if it comes more than that what we can conclude about cement?
It is possible that that cement has been blended with an admixture whose fineness is very high or the admixture may be containing high values of loss on ignition (higher carbon content). In fact when I replaced OPC with 10 % of rice husk ash, I got normal consistency as 39 %. With 20 % replacement, I got still higher value. But I have not found any thing as what we should do with that kind of cement / admixture. Simply reject it?
I have one question : as we know penetration depth of needle should be 33 to 35 from top and 5 to 7 from bottom why there r difference of 10 mm between above approximate reading
The conducted to find out the how much water % is consistency .