No, the changes which have occurred in the cement cannot be reversed because it is a irreversible chemical change.
A bag of cement lying in the open gets wet due to rain during the night. The next day, the sun shines brightly. If due to rain , the cement bag has been wet, then the cement will react with water and will get hardened. This reaction is irreversible in nature and can not be reversed back.
- When water is added to a dry concrete mix a chemical reaction occurs which causes it to harden.
- Once the bag becomes wet , the concrete inside absorbs that moisture, the chemical process begins and the concrete permanently hardens and becomes useless.