Texas Industries, Inc.

Texas Instruments Corporation

David A Crocker

A lightweight cementitious composition comprising a dry mixture of a hydraulic cement component and a lightweight aggregate component of about 75 ppcf or less and a process involving mixing with water to produce a slurry containing at least 4 volume percent entrained air and which is easily workable and sets to produce a lightweight concrete mass having a strength of 2500 psi and a density of 115 ppcf or less. The hydraulic cement component can include two or three cement constituents. One constituent is a Type S, Type M or Type N masonry cement. A second constituent is a pozzolanic cement or an expansive cement, and a third constituent is a Type I cement, Type II cement or a Type III portland cement. In this mixture the first and second cement constituents are each present in an amount less than the third cement constituent. The second aggregate component in the dry mixture comprises a lightweight aggregate present in an mount to provide a bulk density for the dry mixture of no more than 100 pounds per cubic foot and more specifically, a bulk density of about 85 pounds per cubic foot, or less. The cementitious composition forms a readily workable paste which can be characterized as having a slump loss at one half hour of not more than 2 inches after mixing with water. The cementitious composition is conveniently packaged in a unit weighing no more than about 50 pounds per container.

Lightweight cementitious formulations and processes

A light weight cementitious composition comprising a dry mixture of a hydraulic cement component and an aggregate component and which, upon mixing with water, produces a paste which is easily workable and sets to produce a light weight concrete mass. The hydraulic cement component includes at least two and usually three cement constituents. One constituent is a Type S, Type M or Type N masonry cement. A second constituent is a pozzolanic cement or an expansive cement, and a third constituent is a Type I cement, Type II cement or a Type III portland cement. In this mixture the first and second cement constituents are each present in an amount less than the third cement constituent. The second aggregate component in the dry mixture comprises a light weight aggregate present in an amount to provide a bulk density for the dry mixture of no more than 100 pounds per cubic foot and more specifically, a bulk density of about 85 pounds per cubic foot, or less. The cementitious composition forms a readily workable paste which can be characterized as having a slump loss at one half hour of not more than 2 inches after mixing with water in an amount of about 21-23 wt. % of the dry mixture. The cementitious composition is conveniently packaged in a unit weighing no more than about 50 pounds per container.

Light weight cementitious formulations

A fast setting cementitious composition which upon hydration with water forms a paste-like slurry useful in stopping leaks in the walls of cement pipes. The cementitious composition comprises a dry mixture of a hydraulic cement component having a first Portland cement constituent and a second calcium aluminate constituent, an aggregate component and a lime component. Upon hydration with 23 wt. % water, the resulting slurry has an initial Vicat setting time within the range of 1-5 minutes and a final Vicat setting time of no more than 6 minutes. The cement component contains the first and second cement constituents in weight ratios within the range of 3:2-2:3. The lime component is present in an amount within the range of 1-4 wt. %. In effecting the repair of a water leak, a paste-like slurry is formed from water and the dry cementitious composition. The cementitious paste is supplied to the repair site. Sufficient force is applied against the paste to hold it against the repair site while allowing the cement to set to provide sufficient strength to offset the hydraulic gradient and stop the water leakage.

Cementitious formulations and processes

A dry cementitious composition which is shrinkage compensating and fast-setting for use in grouting repair of concrete surfaces. The cementitious composition comprises a hydraulic cement mixture of a major amount of a first portland cement constituent and a minor amount of a second expansive ettringite sulfoalumina cement constituent, an aggregate component, and an accelerator component. The accelerator component is a polyvalent metal salt of formic acid, specifically an alkaline earth metal formate such as calcium formate. Specific formulations include a mixture of Type I, Type IP, or Type III cement as a first constituent with Type K, Type M, or Type S cement as a second constituent, with the ratio of the first to the second constituent within the range of 2-3. The material may be employed to affect a grouting repair by mixing the dry formulation with water to provide a cementitious slurry which sets to provide a compressive strength of at least 4000 psi at 24 hours and a positive volume change of no more than 0.1% at 14 days curing.

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Grand Prairie, TX, United States of America

David A Crocker