Ready Mixed Concrete Highway & Bridge Jobs
Highways & Bridges
The primary, universal, reason that air entrainment is necessary and, as such, specified, has to do with freeze-thaw performance requirements. It is fact that freeze-thaw conditions, as relates to concrete, occur almost everywhere (certainly in North America) at some point during the normal or expected service life of the concrete.
Getting the air right as well as predictable is what Miracon’s® air entrainment is designed to do. It is not just the volume of air, but the quality of air entraining – i.e. the size and spacing – that matter. With Miracon’s® air entrainer there are many additional benefits, besides getting the volume/quality right. The rheological (flow) properties provide better flow and so speed up placement. Additionally, the placement properties it imparts promote better compaction, bonding (to the rebar), finishing, etc. .
The primary, universal, reason for using air entrainment in Bridges/Bridge Decks is very much the same as to why it is used in all other concrete infrastructure – i.e. to relieve internal pressure in any concrete when it freezes. The advantage of using Miracon’s® air entrainment in Bridge/Bridge Deck applications is certainly around the fact that it is significantly more predictable in quality as well as quantity of air entrainment.
Better rheological (flow) properties when placing the concrete also contribute to speed of placement, compaction, bonding to rebar, finishing, etc. . All of these are major positive factors in extending the life cycle of the concrete. Additionally, all of these factors significantly improve not only the placement costs, but also improve the long term service life costs.
See paper : HDOT High Performance Bridge Deck Mix