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AssigneesNippon High Strength Concrete Co., Ltd., Nissan Chemical Corporation
InventorsKenichi Yoshioka, Yuhji Sudoh
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A cement grout material which does not freeze even in an environment where the ambient temperature can be −5° C. or below, and does not require fuel or large-scaled equipment for maintaining curing temperature. Lithium nitrite is added to a cement grout material that contains cement, water and an admixture. By setting the weight ratio of the lithium nitrite to the cement to a value from 3 to 10% by weight, freezing of the grout material is able to be prevented even in an installation environment where the ambient temperature can be −5° C. during the initial stage of installation. By setting the weight ratio of the lithium nitrite to the cement to a value from 4.5 to 8% by weight, freezing of the grout material is able to be prevented even in an installation environment where the ambient temperature can be −10° C. during the initial stage of installation.
An installation method of a cold weather PC cement grout material containing cement, water and an admixture, wherein lithium nitrite is added to said cold weather PC cement grout material, and the weight ratio of said lithium nitrite to said cement is in the range of 3 to 10% by weight, and the compressive strength at 28 days is 30N/mm2 or more, the cold weather PC cement grout material installation method being characterized in that curing and heating is performed such that an installation environment in places to install said cold weather PC cement grout material is kept at a temperature of −5° C. or above when an installation environment where the ambient temperature is lower than −5° C. is reached.
An installation method of a cold weather PC cement grout material containing cement, water and an admixture, wherein lithium nitrite is added to said cement grout material, and the weight ratio of said lithium nitrite to said cold weather PC cement is in the range of 4.5 to 8% by weight, and the compressive strength at 28 days is 30N/mm2 or more, the cold weather PC cement grout material installation method being characterized in that curing and heating is performed such that an installation environment in places to install said cold weather PC cement grout material is kept at a temperature of −10° C. or above when an installation environment where the ambient temperature is lower than −10° C. is reached.
Dependencies are inferred from the claim text.