Overview
In the soundness test a specimen of hardened cement paste is boiled for a fixed time so that any tendency to expand is speeded up and can be detected. Soundness means the ability to resist volume expansion.
Apparatus
Measuring Instruments
| NAME | CAPACITY / RANGE / SIZE | ACCURACY / LEAST COUNT |
| Le-chatelier apparatus | Should be made as per IS:5514 | |
| Water bath | 1000C (min) | 10C |
| Caliper | 30 cm | 0.5 mm |
| Measuring cylinder | 100 ml | 1 ml |
| Balance | 100 g | 1 g |
Other apparatus
| Glass sheets (2 nos), Enamel tray, trowel |
Environmental Conditions
| Temperature | 27 ± 20 C |
| Humidity | 65 ± 5 % |
Procedure
- Before commencing setting time test, do the consistency test to obtain the water required to give the paste normal consistency (P).
- Prepare a paste by adding 0.78 times the water required to give a paste of standard consistency (i.e. 0.78P).
- Lightly oil the Le-chatelier mould and place it on a lightly oiled glass sheet.
- Fill the mould with the prepared cement paste. In the process of filling the mould keep the edge of the mould gently together.
- Cover the mould with another piece of lightly oiled glass sheet, place a small weight on this covering glass sheet.
- Submerge the whole assembly in water at a temperature of 27 ± 20 C and keep there for 24 hours.
- Remove the whole assembly from water bath and measure the distance separating the indicator points to the nearest 0.5 mm (L1).
- Again submerge the whole assembly in water bath and bring the temperature of water bath to boiling temperature in 25 to 30 minutes. Keep it at boiling temperature for a period of 3 hours.
- After completion of 3 hours, allow the temperature of the water bath to cool down to room temperature and remove the whole assembly from the water bath.
- Measure the distance between the two indicator points to the nearest 0.5 mm (L2).
Calculations
Soundness/expansion of cement = L1-L2
L1=Measurement taken after 24 hours of immersion in water at a temp. of 27 ± 20 C
L2=Measurement taken after 3 hours of immersion in water at boiling temperature.
Calculate the mean of two values to the nearest 0.5 mm.
- Note::In the event of cement failing to comply with the specified requirements, a further test should be made from another portion of the same sample in manner described above, but after aeration (done by spreading out to a depth of 75 mm at a relative humidity of 50 to 80% for a total period of 7 days).
Precautions
- All the measurements should be done accurately.
- Do not apply extra pressure while filling the moulds.
- During boiling water level should not fall below the height of the mould.
Standard Specifications
| Type/Name of cement | Reference Indian standard | Expansion (max.) |
| OPC (33) | IS:269-1989 | 10 mm |
| OPC (43) | IS:8112-1989 | 10 mm |
| OPC (53) | IS:12269-1987 | 10 mm |
| Rapid hardening | IS:8041-1990 | 10 mm |
| Low heat cement | IS:12600-1989 | 10 mm |
| Super sulphated | IS:6909-1990 | 5 mm |
| Portland pozzolana | IS:1489-1991(part 1) | 10 mm |
| PSC | IS:455-1976 | 10 mm |
| High alumina cement | IS:6452-1989 | 5 mm |
| SRC | IS:12330-1988 | 10 mm |
| Masonry cement | IS:3466-1988 | 10 mm |
| IRS-T-40 | Railway standards | 5 mm |
Technical Discussion
- Volume expansion in cement mortar or in cement concrete is caused by the presence of unburnt lime (CaO), dead burnt MgO and also CaSO4.
- By Le-chatelier method we can only find out presence of unburnt lime (CaO).
- Presence of unburnt lime may develop cracks in the cement because of increase in volume.
- Free lime (CaO) and magnesia (MgO) are known to react with water very slowly and increase in volume considerably, which result in cracking, distortion and disintegration.
Test Standard Reference
- IS:4031(Part 3):1988-Methods of physical tests for hydraulic cement (Determination of soundness)
Why autoclave goes to -indicate what is the reason
why we should cement put in bolling water
ham water ko gram water main knu dalty hn???
If the expansion is 0.7mm I mean very less than 10mm. what would be reason for it??
I have a doubt . Whether it is L1-L2 or L2-L1??
I think L2< L1 and hence it should be L2-L1….
please resolve my query.
what is that 0.78 factor ?
please share to [email protected] id
It is too interesting in reading from this site. Huge compliments to the creator.
Why taking water quantity of 0.78 time of consistacy…plz
As we are trying to find out the unsoundness ,for the worst case there should be sufficient free CaO and MgO to cause unsoundness. That’s why we are using lesser amount of water than the amount required for complete cement-water reaction.
What should we do if the soundness of cement is found to be 13mm?
Why do we make auto clave in physical lab??.. Whts d reason pls tell me smeone
What Physical and chemical test of cement?
If lechatelier expansion is more 10mm…what will happen in chemical reaction…
That cement not suitable for work
Normally Soundness of cement by le-chateliers test getting expansion is less than 10 mm, such as 1.5 mm, but we found cracks in concrete so what will be another reason for develop the crack.
pl. let me give reason for that?
Thanks & Rgd
Hemant Mahulkar
Crarks may get developed due to presence of Air voids in the Structure….
There air voids must have removed by Compaction before setting of cement…..
Cracks may also get introduced due to not properly moisturing the Structure…..
After Completely plastering, the Structure must be watered for 20 – 28 days….
Accept it if it is found right….
By AJ..
Sir Plz Update the IS Code mention above for OPC
thanks for sharing this site..
Thanks sir for availability of site
why 0.78 Percentage of water is added in soundness test?
Thanks for you
Mast site
Love the site
Thanks for sharing this useful information ,tests on cement bcz it’s unavailable in our civil text book and I have write my project on it
Thanks for sharing this information about soundness of cement.
This is great to look such a civil engineering descriptive experiment article here.
Love the site. Thank you.
Thanks for you