Bolt cement for securing bolts in boreholes in rock and concrete and anchoring prefabricated concrete elements, method for producing the bolt cement, and the use thereof

摘要

The bolt cement for securing bolts in boreholes in rock and concrete and for anchoring prefabricated concrete elements consists of cement, binding-time-regulating and strength-regulating additives, and additives for regulating the consistency of the cement paste. The cement has a content of tricalcium aluminate which is less than 5% by weight and is ground to a specific surface of 500-700 m2/kg using from 0.1 to 1.0% by weight of sulphonated lignin as grinding agent. The binding time and the strength are regulated by additions of 0.1-1.0% by weight of sulphonated polyelectrolytes such as lignosulphonate, sulphonated lignin, sulphonated condensates of naphthalene, melamine or phenol, or corresponding condensates containing formaldehyde and 0.2- 2.0% of an alkali metal carbonate such as K2CO, Na2CO3, KHCO3 or NaHCO3, and the consistency is regulated with 0.1-1.0% by weight of amorphous silicic acid having a specific surface greater than 100,000 m2/kg. IMAGE