Lightweight insulating structural concrete
OwnerLayton L. Raylinventor
Life of this patent
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Abstract
A lightweight insulative, structural concrete is produced from a cement mix containing lightweight aggregates having precisely defined physical and chemical properties. These aggregates are very low in density and very high in amorphous SiO.sub.2 content. The concrete product produced using the mix of this invention has a unique combination of high structural strength (up to 3400 psi, 28-day compressive), low density (50 to 110 pounds per cubic foot) and high thermal resistance (R) values (up to 3.16/inch). Such a product is just as strong, one half the weight, and 36 times more insulative than ordinary hard rock concrete.
Claims35
A hardened lightweight insulative cementitious product having a 28-day cure compressive strength of at least about 2500 psi a thermal resistance (R) value of at least about 2.5/inch and a density of less than about 110 pounds per cubic foot, said cementitious product comprising lightweight aggregates bonded together with a hydrated Portland cement, said lightweight aggregates comprising a lightweight fine aggregate having an amorphous SiO.sub.2 content of at least about 75% by weight, a density of less than about 60 pounds per cubic foot, and from about 60 to about 85% by volume of void space.
A method for making a precast, insulative, lightweight cementitious product having a 28-day cure compressive strength of at least about 2500 psi, a thermal resistance (R) value of at least about 2.5/inch and a density of less than about 110 pounds per cubic foot, said method comprising the steps of:
- (a) providing a concrete mix comprising Portland cement and lightweight aggregates said lightweight aggregates comprising a lightweight fine aggregate having an amorphous SiO.sub.2 content of at least about 75% by weight, a density of less than about 60 pounds per cubic foot, and from about 60 to about 85% by volume of void space.
- (b) adding sufficient water to said mix to form a castable concrete mixture;
- (c) pouring said concrete mixture into a form of predetermined size and configuration;
- (d) drawing a vacuum on said concrete mixture in said form to remove excess free water;
- (e) curing said concrete mixture in said form for a period of time sufficient to impart handling strength to said product;
- and
- (f) drying said cured concrete mixture at a temperature and for time sufficient to remove substantially all of the free water in said product.
Dependencies are inferred from the claim text.