What is soundness test of cement? It is probably one of the most significant and relevant queries that arise in our mind whenever we discuss the characteristics and properties of cement in a broader way. Cement is the most important construction material among all the building materials, and the reason behind is its ability to combine and integrate all the other constructional materials. The soundness of cement is the property by virtue of which the cement does not show any expansion due to volume change after it has set. Soundness test is the test that determines the soundness of the cement.

So that the expansion after it has set, thus eliminating the chances of disruption of mortar. We also conduct a test to determine the Vicat Apparatus Test – Initial and Final Setting time of Cement, and Sieve Test Procedure To Check Fineness Of Cement, to know the properties of cement. But the soundness test of cement is performed with the help Le-Chatelier apparatus which is named after the great scientist Le-Chatelier. In this article, we are going to discuss the apparatus, procedure, theory, procedure, and precaution that are to be taken into consideration while performing soundness test.

Aim

To determine the soundness of cement by Le-Chatelier apparatus.


soundness test of cement

Apparatus required

  • Le-Chatelier apparatus (IS:5514)
  • Balance: It should be capable of measuring 100g to variation of 1g, the permissible variation at a load of I 000 g shall be plus or minus 1’0 g. The permissible variation in new balance shall be one-half of this value. The sensibility reciprocal shall be not greater than twice the permissible variation.
  • Water Bath: Water bath capable of containing immersed Le-Chatelier moulds with specimens and of raising their temperature from 27 ± 2°C to boiling in 27 ± 3 minutes.

Theory

  • Soundness means the ability to resist the volume expansion. The hardened cement paste is mixed with boiled water to read the tendency of expanding.
  • Volume expansion in cement mortar or 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 the existence of unburnt lime (CaO).
  • The 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.

Indian Standard Specifications For Soundness Test For Cement

S. No.Reference Indian StandardType of CementLimit of Expansion
1.IS:269-1989OPC (33)10 mm
2.IS:455-1976PSC10 mm
3.IS:3466-1988Masonry cement10 mm
4.IS:6452-1989High alumina cement5 mm
5.IS:6909-1990Super sulphated5 mm
6.IS:8041-1990Rapid hardening10 mm
7.IS:8112-1989OPC (43)10 mm
8.IS:12269-1987OPC (53)10 mm
9.IS:12330-1988SRC10 mm
10.IS:12600-1989Low heat cement10 mm
11.IS:1489-1991(part 1)Portland pozzolana10 mm
12.Railway standardsIRS-T-405 mm

Procedure

(i) Make cement paste by gauging it with 0.78 times water for the standard consistency.
(ii) Place the mould on a glass sheet and filled it with the cement paste.
(iii) Place another glass sheet on the mould, also, put a small load on the glass sheet and submerge it in water at a temperature of 27±2° C.keep it nearly for 24 hours.
(iv) Remove it from the water bath and measure the separating distance between the indicator points nearly to the 0.5 mm (D1).
(v) Again submerge it in the water bath and bring the temperature of water to boiling point in 25-30 minutes. Keep it at this temperature for 3 hours.
(vi) Now after 3 hours, allow it to cool down to room temperature and take it out from the water bath.
(vii) Finally, measure the distance separating the two indicator points nearly to the 0.5 mm (D2).

Calculation

Soundness of cement = D- D2
Where,
D1= the separating distance between the indicator points nearly to the 0.5 mm.
D2= the distance separating the two indicator points nearly to the 0.5 mm.

Precautions

  • Measurement should be accurate.
  • Don’t apply extra pressure while filling the cement paste in the mould.
  • Do not use extra pressure while filling the moulds.
  • While boiling water level should not fall below the height of the mould.

Why Is Soundness Test Done?

Soundness test is essential for determining some of the most properties of cement. The various application of soundness test of cement are as follows:

  • Soundness finds its application in determining the cracks formed.
  • Undue expansion of the cement and
  • To determine the disintegration of concrete.

Other Methods For Determining The Soundness Of Cement

The methods for the determination of soundness of cement are as follows:

  • Le-Chatelier method of soundness test of cement.
  • Autoclave method of soundness test of cement.

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