Retempering of Concrete
When water is added to hardened concrete or partially set to return the fresh concrete to the desired consistency or workability, it is called “recycling of concrete,
Importance of Retempering Concrete
The only reason concrete is re-tempered is to recover the lost workability of fresh concrete to make it usable. The reason behind the loss of practicality is the delay between the mixing of the concrete material and the placing of the concrete on the actual site. This type of delay can happen in the following situations.
- Concrete delivery from central mixing plant to work site due to traffic
- When building long tunnels or in road works
- When pouring concrete manually by laborers in hilly areas
Since concrete is a very expensive material, it cannot be wasted without any justifiable reason. That is why in order to make concrete workable, water is added to the concrete and mixed again to regain its lost workability.
Sometimes the engineer in charge may not allow the concrete to be changed frequently due to the importance of the structure or the project specification. So you need to consult the engineer on site to find the solution of the problem
- Always remember that retempering of concrete should be allowed only if the hardened concrete can be used on the job without any damage.
- Always add a small amount of additional cement to balance the water-cement ratio of the concrete.