Abstract A waterproofing barrier characterized by its controlled swelling when wet and comprising in admixture a water-swellable colloidal clay, such as bentonite, and a particulate, inorganic metal salt treated with an oleaginous carboxylic acid. Preferably, the metal salt is calcium carbonate, such as amorphous chalk, treated with an acid like oleic or stearic acids. The mixture is particularly adapted as a protective layer in a below grade concrete roof system, or the like, above which is a pavement, earth, walks, etc., are to be laid. The present mixture may be used alone as in layer form or in conjunction with an adjoining layer of waterswellable clay to form a multilayer barrier. Optionally, the mixture may include a finely divided siliceous mineral such as perlite as an additional ingredient.
The waterproofing barrier of claim 1 wherein said inorganic metal salt is selected from the group consisting of calcium carbonate, calcium sulfate, calcium chloride, barium carbonate, barium sulfate, and barium chloride.
Claim 2
Dependent Claim
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The waterproofing barrier of claim 1 wherein said inorganic metal salt is calcium carbonate.
Claim 3
Dependent Claim
13 words
The waterproofing barrier of claim 4 wherein said calcium carbonate is amorphous chalk.
Claim 4
Dependent Claim
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The waterproofing barrier of claim 1 wherein said oleaginous carboxylic acid is selected from carboxylic acids having from 13 to 22 carbon atoms.
Claim 5
Dependent Claim
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The waterproofing barrier of claim 1 including a finely divided siliceous mineral selected from the group consisting of perlite and vermiculite.
Claim 6
Dependent Claim
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The waterproofing barrier of claim 7 wherein said water-swellable clay is present in an amount of about 7.5 to about 60 percent by volume, and each of said metal salt and siliceous mineral is present in an amount of about 20 to about 60 percent by volume.
Claim 7
Dependent Claim
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A waterproofing barrier of claim 1 wherein said mixture is compacted, and a sufficient amount of said water-swellable clay is present to seal when wet relatively minor punctures in the compacted mixture.