The soundness of cement and hydrated lime is of particular importance. It is essential that once hardened the paste does not undergo a large change in volume.

The soundness of cements and limes can be determined by an expansion test using Le Chatelier Moulds. The method of curing lime differs from that of cements, lime being cured in a steam tank and cements in a water bath. The ASTM method uses a high-pressure steam vessel (Autoclave) to cure the specimens.