ABSTRACT
To obtain satisfactory workability the contractor must add a significant dosage of water reducing additives. This may lead to long setting time, and in some cases the concrete can loose its workability in a very short time. The composition may also lead to stickiness, high viscosity and crust formation, all of which may cause problems during execution of the concrete works. Well established execution methods may as a consequence no longer be adequate when such high performance concretes are used.
