A concrete is said to be of good quality, if it is strongest, densest, most workable and most economical for the job for which it is prepared. Amount of cement used in concrete should be low and that of aggregate should be high. If the following general requirements are fulfilled, then we can produce the most economical concrete with highest possible density.
Requirements to be Fulfilled
The air bubbles should be eliminated from the body of the concrete
The cement particles should be of the smallest size
The concrete must be compacted fully so as to remove voids.
The concrete should be cured sufficiently and adequately, say for 28 days.
Wherever possible cubical particles of the aggregates should be used so that good interlocking is gained.