MasterSet AC 555

Set accelerating admixture for concrete

How does MasterSet AC 555 work?

MasterSet AC 555 is a ready-to-use liquid admixture formulated to accelerate setting time and to produce high early strength in special application concretes.

What is MasterSet AC 555 used for?

MasterSet AC 555 is recommended for use in concrete to be placed on galvanised steel flooring and roof systems; pre-stressed concrete (either pre-tensioned or post-tensioned); concrete bridge deck repairs; concrete pipes and concrete containing steel reinforcement.
Neither calcium chloride nor any other intentionally added chloride-containing ingredients are used in the manufacture of MasterSet AC 555 admixture. Therefore, MasterSet AC 555 admixtures will not initiate or promote corrosion of steel embedded in concrete.

What are the benefits of MasterSet AC 555?

The compressive and the flexural strengths of concrete containing MasterSet AC 555 accelerating admixture will develop more rapidly compared to plain concrete. Benefits to concrete construction and to the manufacture of concrete products because of the increase in early strengths are as follows:

  • Earlier stripping and re-use of forms for walls and pre-cast work.
  • Earlier structural use of concrete, as in lift-slab construction, tilt-up, paving and floors.
  • Earlier tensioning in post-tensioned concrete.
  • Earlier de-tensioning in pre-stressed concrete.
  • Potential energy savings in accelerated steam-cured applications (pre-stressed concrete).
  • Potential energy savings in accelerated steam-cured applications (pre-stressed/pre-cast) by reducing curing temperatures and/or the curing time necessary to reach the desired strengths.

Concrete with MasterSet AC 555 has a significantly faster setting time than plain concrete. Increasing the dosage rate of this product increases set acceleration. Tests have demonstrated that MasterSet AC 555 admixture can produce setting time acceleration equivalent to that produced when 2% calcium chloride is added to a concrete mix. This is dependent on the type and source of the cement.
Particularly beneficial in cold weather, reduction in setting time allows for the earlier finishing of concrete. This can result in substantial time and money savings in construction through better scheduling, fewer cold weather delays, faster construction and earlier occupancy.

Direct contact

Ian Ellis

Technical Services Manager

+44 7966 123447


MasterSet AC 555 Declaration of Performance

pdf (63.95 Kb)

MasterSet AC 555 SDS

pdf (88.11 Kb)

MasterSet AC 555: Technical Data Sheet

pdf (111.02 Kb)