Atlanta-based Big River Industries produces high-quality expanded clay lightweight aggregates.
In 2012, ASTM published the Standard Specification for Lightweight Aggregate for Internal Curing of Concrete, a guideline for using pre-moistened lightweight, porous aggregate to achieve high-level hydration.
Concrete producers are using expanded lightweight clay aggregate such as Riverlite, to produce mix designs that meet high-performance specifications for bridge decks.
Internal curing with lightweight aggregate can reduce or eliminate cracking in bridge decks by drastically reducing shrinkage.
Contractors report no noticeable difference in placing internally cured concrete compared to ordinary bridge deck concrete.
The ASTM Standard Specification for Lightweight Aggregate for Internal Curing of Concrete has begun to impact concrete projects contracted by the U.S. Federal Highway Administration and state departments of transportation as well as architects, contractors, producers, and engineers.