The Objectives of SCC should meet the some functions at the plastic stage are different from those on a traditional vibrated fresh concrete. Filling of formwork with a liquid suspension requires workability performance which is recommended to be described as follows:
- Filling Ability
SCC is filling of entire formwork and encapsulation of reinforcement and other inserts with maintaining homogeneity in both vertical & horizontal directions are essential.
- Passing Ability
Objectives of SCC is passing through congested area such as narrow sections of the formwork even closely spaced reinforcement etc without blocking caused by interlocking of aggregate particles.
- Resistance to Segregation
SCC is maintaining of homogeneity throughout mixing and during transportation and casting. The dynamic stability refers to the resistance to segregation during placement. The static stability refers to resistance to bleeding, segregation and surface settlement after casting.
- Open Time
Open time has to be closely following specified time duration for initial setting. New generations of admixtures offer increased possibilities of setting a specified target open time, e.g. very short for precast applications and very long for in-situ castings with long haulages.
- Precision & Accuracy
More essential to keep target workability for SCC as the casting is fully relying on the material properties as no tools normally will be available for manual material transport and compaction.
- Pumping Ability
More essential to keep target workability for SCC as the casting is fully relying on the material properties as no tools normally will be available for manual material transport and compaction.
- Finishing Ability
SCC normally has less bleeding tendency. In many cases the finishing will be made on a coarser and stickier surface. Appropriate materials on the finishing tools are thus to be recommended.