| 摘要 |
<p>The invention relates to an additive for cement or mortar, which comprises a mixture of at least one constituent selected from the group consisting of water- reducing and high-grade water-reducing agents for cement and concrete and microsize silicon dioxide, where this constituent is dispersed in silicon dioxide. The microsize silicon dioxide makes up from 30 to 98% by weight of the mixture and the water-reducing constituent is present in an amount of from 2.0 to 50% by weight, based on the weight of the microsize silicon dioxide, with the mixture being slurried in water and/or an organic liquid and the proportion of solids in the slurry being from 20 to 80% by weight. In one embodiment, the additive contains at least one water-reducing agent and at least one high-grade water- reducing agent and, if desired, at least one accelerator and/or at least one retarder and/or at least one air- introducing agent. The microsize silicon dioxide used is preferably isolated from the offgas of an electric furnace in which ferrosilicon or silicon metal is produced.</p> |
