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

Read a paper on FLAIR that was presented at the 4th International Seminar on Self-Desiccation and Its Importance in Concrete Technology

View the Powerpoint presentation on FLAIR that was made at the 4th International Seminar on Self-Desiccation and Its Importance in Concrete Technology