Cement is very important binding material. It is mostly used to make cement mortar and concrete. Cement has a property to get hardened and to achieve strength within a short period of a time in presence of water. It is therefore very important for us to know in how much time cement will set and in how much time we will have to use the cement.
When water is mixed with cement, the paste is formed and remains in the plastic state for a first few minutes. During these first few minutes the paste can be mould in any required shape due to its plasticity.Within this specific time reaction continues between cement and water. During this reaction, paste loses its plasticity and gets hardened. Afterward, moulding the hardened paste in the desired shape becomes difficult. This early time of the hardening of cement paste is known as “Setting Time of Cement”.
Initial Setting time of Cement:
The time to which cement can be moulded in any desired shape without losing it strength is called Initial setting time of cement
The time at which cement starts hardens and completely loses its plasticity is called Initial setting time of cement.
For Ordinary Portland Cement, The initial Setting Time is 30 minutes.
Final setting time of Cement:
The time at which cement completely loses its plasticity and became hard is a final setting time of cement.
The time taken by cement to gain its entire strength is a Final setting time of cement.
For Ordinary Portland Cement, The Final Setting Time is 600 minutes (10hrs).