Processed mineral additive for reducing concrete permeability and increasing strength

摘要

A packaged concrete additive includes ground, expanded perlite with a volume weighted mean particle size of approximately 10-100 μm. The perlite optionally includes at least one additional component to improve workability and compensate for the natural tendency of expanded perlite to absorb water from the concrete mix. The additional component can include: water; a superplasticizer such as polycarboxylates, naphthalene sulfonate, and melamine sulfonate; or a hydrophobic compound, such as salts of fatty acids, fatty acids, silanes, and siloxanes. The additive is a flowable powder and for convenience of use it is packaged in a bag that can be directly added to the concrete batch and disappears on mixing. Concrete containing this additive displays superior properties to conventional concrete. Expanded perlite is a readily available raw material and the finished concrete is suitable where high strength structural concrete must withstand high temperatures.

主权项

1. A concrete additive package comprising:
a flowable powder comprising ground, expanded perlite with a volume weighted mean particle size of approximately 10-100 μm and a moisture content of 10 to 50% by weight, said flowable powder contained within a moisture-retentive package that may be directly added to a concrete mix.