FLAIR: Fine Lightweight Aggregates as Internal Reservoirs
FLAIR consists of a unique method to control the distribution/delivery of chemical admixtures within a hardening concrete. Recently, the usage of saturated fine
lightweight aggregates to provide internal curing water to promote cement hydration
in hardening concrete with a low water to cementitious binder (w/c =0.42 and lower)
has been demonstrated in the laboratory and the field. The novel aspect of FLAIR
is to utilize these same internal reservoirs to supply chemical admixtures such as shrinkage-reducing admixtures, corrosion inhibitors, etc. to the concrete.
As the cementitious components of the concrete react with the mix water, the hydration products
occupy less volume than the starting materials. Thus, a concrete will imbibe
water from its immediate surroundings or from internal sources (containing larger pores)
to maintain a saturated capillary porosity. While to date, the internal reservoirs
have been saturated mainly with water, they could equally be saturated with
solutions of chemical admixtures.
FLAIR technology has been evaluated at NIST (See links below.) and is also being
evaluated at a number of chemical admixture companies including Sika and W.R. Grace in the USA
and Maxit group in Europe.
For more information contact Dale P. Bentz