Methods of controlling the durability of and/or the amount of air in
concrete formulations that include combining cement, water, and
optionally aggregates, admixtures and/or additives to form a cement
mixture; and adding prepuff particles to the cement mixture to form a
concrete formulation. The prepuff particles have an average particle
diameter of from 0.2 mm to 3 mm, a bulk density of from 0.015 g/cc to
0.35 g/cc, an aspect ratio of from 1 to 3, and a smooth continuous outer
surface. The cured and hardened concrete formulation typically has a
relative dynamic modulus of at least 70% determined according to
Procedure A of ASTM C666 (2003). The amount of air in the concrete
typically increases over the amount of air in similar formulations not
containing prepuff particles, as determined according to ASTM C231, based
on the volume percent of prepuff. The concrete formulations can be used
to make articles.