Soundness – The soundness test determines whether hardened cement paste is prone to excessive expansion by boiling the test specimens for a fixed period of time. The soundness of cement is mainly tested by two methods: EN-196 (1995), which is based on the Le Châtelier test method, and the autoclave test (ASTM-C151, 2015), in which pressure is also applied to the sample.
- The soundness values for hardened cement paste specimens produced with 2.5–6% CS ( Alp et al,
- 2008 ) showed an average reduction of 13% in expansion when compared to control specimens without CS.
- Other studies also showed that the incorporation of CS as part of the raw feed may allow the production of cement clinker with equivalent ( Ali et al., 2013 ) or lower expansion ( Supekar, 2007 ) than that of control PC without CS.
Expansion of specimens containing 2.5% CS decreased by 20% when compared to the corresponding PC specimens. These results can be correlated with the decrease in the free CaO content ( Alp et al., 2008; Supekar, 2007 ). The reason for this is that, by applying elevated temperatures (or pressure in the autoclave test method), it is possible to measure the extent of expansion caused by the delayed hydration of unburnt CaO.
Contents
Why to do soundness test of cement?
What is Soundness test of cement? – The soundness test of cement is one of the methods to determine the volume change in cement and concrete after the setting. Excessive expansion after the setting is said to be unsound. It is done by two methods namely Le-Chatelier Method and the Auto-Clave test,
How do you test the quality of cement?
What is Soundness test of cement? – The soundness test of cement is one of the methods to determine the volume change in cement and concrete after the setting. Excessive expansion after the setting is said to be unsound. It is done by two methods namely Le-Chatelier Method and the Auto-Clave test,
What is soundness test of cement (Le Chatelier method)?
Soundness Test of Cement (Le-Chatelier Method) – It is very important that the cement after setting shall not undergo any appreciable change of volume. The soundness of cement, fly ash for concrete and lime is determined by using the Le Chatelier moulds and Le Chatelier Water Bath according to the relevant standard.
How to check if a cement is unsound?
Conclusion –
| Cement types | Permissible soundness/expansion |
| OPC,RHC,LHC,PCC | 10mm |
| HAC,SSC | 5mm |
Where, OPC= Ordinary Portland Cement RHC=Rapid Hardening Cement LHC= Low Heat Cement PCC= Portland Pozzolano Cement HAC= High Alumina Cement SSC= Super Sulphate Cement If the obtained value of soundness is more than permissible than the cement is said to be unsound.
- To cross-check this cement, another experiment called aeration + le-Chateliers method is done.
- In this test, at first, the cement is aerated by spreading out to a depth of 75 mm and store it for 7 days in an atmosphere maintained at 27±2°C and relative humidity of 50 to 80 percent.
- After this, a cement sample of required weight for the Le-Chateliers Method is taken from the aerated sample and the same steps explained above are done.
If the result obtained again is above the permissible value, then the sample is not preferred in construction.
