Cement Content:

At the given water content if quantity of cement is reduced it will lead to a harsh mix, which is less workable. There is certain hardness in handling the harsh mix such as, difficulty in compaction, poor finishability, presence of more voids, etc. On the other hand, large quantity of cement (within limit) increases the cohesiveness hence, the workability of concrete mix. But, taking undue large quantity of cement will lead to uneconomical mix and will also increase the shrinkage of concrete.

Aggregate-Cement Ratio

Aggregate-cement ratio also plays an important role in governing the workability of concrete mix. It is necessary to maintain the adequate aggregate-cement ratio in order to ensure the availability of sufficient quantity of cement paste for providing the lubrication. Therefore, for high aggregate-cement ratio (i.e. for the lean mix) less paste will be available for lubrication hence, the workability reduces. On the other hand, for low aggregate-cement ratio (i.e. for the rich mix) the workability improves.