In spite of the lower cement content we pay about the same for gap-graded concrete as for continuously graded mixes. We use it in architectural concrete work. It costs us a lot more to handle and place it, however, so our total costs are higher. We don't see any way around this and wonder what other people's experience has been.
Contractors report that on many projects gap-graded concrete costs twice as much to place as conventional concrete. This point makes the savings effected in cement negligible. The slump must be maintained low and, as a result, the stiffer mix must be handled only by certain types of mixers and placing buckets. It is true that the concrete is workable but it does not flow.