Freeze-thaw durable geopolymer compositions and methods for making same

A method for making a geopolymer composition comprising the steps of:

• preparing and aerating a slurry by mixing
• water;
• air;
• cementitious reactive powder comprising:
• thermally activated aluminosilicate mineral in an amount of 100 parts by weight,
• aluminate cement in an amount of 1 to 100 parts by weight (pbw) per 100 pbw of thermally activated aluminosilicate mineral, and
• calcium sulfate in an amount of 2 to 100 parts by weight per 100 pbw of aluminate cement, wherein the calcium sulfate is selected from at least one member of the group consisting of calcium sulfate dihydrate, calcium sulfate hemihydrate, and anhydrous calcium sulfate;
• and
• alkali metal chemical activator in an amount of 1 to 6 weight % based upon the total weight of the cementitious reactive powder, wherein the alkali metal chemical activator is selected from at least one member of the group consisting of an alkali metal salt and an alkali metal base;
• freeze-thaw durability component in an amount of 0.05 to 21.5 weight % based upon the total weight of the cementitious reactive powder, the freeze-thaw durability component comprising:
• air-entraining agent in an amount of 0 to 1 weight % based upon the total weight of the cementitious reactive powder,
• defoaming agent in an amount of 0 to 0.5 weight % based upon the total weight of the cementitious reactive powder, and
• surface active organic polymer in an amount of 0 to 20 weight % based upon the total weight of the cementitious reactive powder;
• optional superplasticizer;
• wherein at least one member of the group consisting of the air-entraining agent defoaming agent, and the surface active organic polymer is present,
• wherein said thermally activated aluminosilicate mineral, said aluminate cement, and said calcium sulfate is at least 70 wt. % of the cementitious reactive powder;
• wherein the water/cementitious reactive powder weight ratio of the slurry is 0.14 to 0.45:1,
• setting the slurry to form a set composition;
• wherein the set composition has a freeze-thaw durability performance according to ASTM C666/C666M-15 of a relative dynamic modulus of greater than 80 percent for at least 100 freeze-thaw cycles.

A settable composition for making a freeze-thaw durable, dimensionally stable, geopolymer composition when reacted in water comprising a mixture of:

• cementitious reactive powder comprising:
• thermally activated aluminosilicate mineral in an amount of 100 parts by weight,
• aluminate cement in an amount of 1 to 100 parts by weight (pbw) per 100 pbw of thermally activated aluminosilicate mineral, and
• calcium sulfate in an amount of 2 to 100 parts by weight per 100 pbw of aluminate cement, wherein the calcium sulfate is selected from at least one member of the group consisting of calcium sulfate dihydrate, calcium sulfate hemihydrate, and anhydrous calcium sulfate;
• and
• alkali metal chemical activator in an amount of 1 to 6 weight % based upon the total weight of the cementitious reactive powder, wherein the alkali metal chemical activator is selected from at least one member of the group consisting of an alkali metal salt and an alkali metal base;
• freeze-thaw durability component in an amount of 0.05 to 21.5 weight % based upon the total weight of the cementitious reactive powder, the freeze-thaw durability component comprising:
• air-entraining agent in an amount of 0 to 1 weight % based upon the total weight of the cementitious reactive powder,
• defoaming agent in an amount of 0 to 0.5 weight % based upon the total weight of the cementitious reactive powder, and
• surface active organic polymer in an amount of 0 to 20 weight % based upon the total weight of the cementitious reactive powder;
• optional superlasticizer;
• wherein at least one member of the group consisting of the air-entraining agent, defoaming agent, and the surface active organic polymer is present,
• wherein said thermally activated aluminosilicate mineral, said aluminate cement, and said calcium sulfate is at least 70 wt. % of the cementitious reactive powder,
• wherein the composition after being mixed with water and air and setting will make the freeze-thaw durable, dimensionally stable, geolpolymer composition to have a freeze-thaw durability performance according to ASTM C666/C666M-15 of a relative dynamic modulus of greater than 80 percent for at least 100 freeze-thaw cycles.