The correct answer is: D. All of above
Workability of concrete is a measure of how easy it is to place, compact, and finish. It is affected by a number of factors, including the aggregate cement ratio, time of transit, and grading of the aggregate.
The aggregate cement ratio is the ratio of the weight of aggregate to the weight of cement in the concrete mix. A higher aggregate cement ratio will result in a more workable concrete mix. This is because the aggregate particles will fill in the voids between the cement particles, making the concrete mix more cohesive and easier to place and compact.
The time of transit is the amount of time that elapses between when the concrete is mixed and when it is placed. A longer time of transit will result in a less workable concrete mix. This is because the cement particles will start to hydrate and form a gel, which will make the concrete mix more viscous and difficult to place and compact.
The grading of the aggregate is the distribution of the sizes of the aggregate particles in the concrete mix. A well-graded aggregate will result in a more workable concrete mix. This is because the aggregate particles will interlock with each other, creating a more stable and cohesive concrete mix.
In conclusion, the workability of concrete is directly proportional to the aggregate cement ratio, time of transit, and grading of the aggregate.