Aggregate Absorbtion
Aggregate Absorbtion
(OP)
Hello,
I would like to know the problems associated with excessive aggregate absorbtion within concrete and the specifications associated with this area.
Tim
I would like to know the problems associated with excessive aggregate absorbtion within concrete and the specifications associated with this area.
Tim





RE: Aggregate Absorbtion
Absorptive aggregates are difficult to maintain in a saturated, surface dry condition (the basis for mix design proportion computations) so the tendency to have difficulty in controlling the workability of the mix is usually greater. Takes a lot of effort on the part of Ready Mix supplier. Slump loss during placement or pumping can be pronounced, leading to excessive retempering, which is not good for the strength or durability of the concrete.
Absorptive aggregates have less natural resistance to freeze-thaw as their void structure allows water to freeze and deteriorate the aggregate.
Natural limestone aggregate is a common absorptive aggregate used in Florida and other locations with excellent success, but requires recognition of the quirks of the material.
RE: Aggregate Absorbtion
I would echo Ron's comments on the difficulty in maintaining a consistant mix delivery to the job, especially from a nearby plant when minimum allowable mixing takes place. A highly absorptive material can drive a tester mad at the slump cone.