Test for Freshness of Cement
Indications of a damaged cement are given by the presence of large lumps of set cement, and when this happens the lumps should be screened out unless they are soft enough to be powdered when pressed in the fingers. It needs to be considered if this cement is to be rejected.
When cement is rubbed between fingers and thumb it should feel like a smooth powder such as flour. Grittiness may indicate deterioration. Such a cement should be tested for setting time. If caked material is screened out and the balance used with 10 per cent extra cement, the concrete will be good for common small works, though it will be slow setting.