초록 ▼

A shaped article with a binder matrix based on cement is prepared from a mix comprising the cement, water, and a concrete super-plasticizer, the weight ratio between the water and the cement being at the most 0.30, preferably at the most 0.25, arranging the mix in the desired configuration and allow

A shaped article with a binder matrix based on cement is prepared from a mix comprising the cement, water, and a concrete super-plasticizer, the weight ratio between the water and the cement being at the most 0.30, preferably at the most 0.25, arranging the mix in the desired configuration and allowing the mix to solidfy, in which mix the weight amount of water-soluble alkali in the mix originating from the mineral solids in the mix is reduced to at the most 0.30%, preferably at the most 0.25%, more preferably at the most 0.20%, calculated as Na2O equivalents, relative to the weight of the cement in the mix. The mix preferably further contains a fine silica-rich powder. The mix has an advantageously high fluidity rendering it useful for the preparation of shaped articles.

대표청구항 ▼

A method for preparing a shaped article with a binder matrix prepared from a mix consisting essentially of a Portland cement, a fine silica-rich powder, water and a concrete superplasticizer, in the proportions of at least 0.1 part of the silica-rich powder, up to 0.35 part water, and from 0.01 to 0

A method for preparing a shaped article with a binder matrix prepared from a mix consisting essentially of a Portland cement, a fine silica-rich powder, water and a concrete superplasticizer, in the proportions of at least 0.1 part of the silica-rich powder, up to 0.35 part water, and from 0.01 to 0.04 part of the concrete superplasticizer dry matter per part by weight of the mixture of the cement and silica-rich powder, the method comprising (a) selecting the cement and fine silica-rich powder by measuring the contents of water-soluble Na and K in the cement and the fine silica-rich powder, calculating the contents of water-soluble Na and K as Na2O-equivalents, and selecting a cement and a fine silica-rich powder that will result in a content of water-soluble alkali metal in the mix originating from the cement or the fine silica-rich powder of at the most 0.30%, calculated as Na2O equivalents, based on the weight of the cement in the mix, (b) preparing a mix comprising the cement, the fine silica-rich powder, water, and a concrete superplasticizer, (c) arranging the mix in a shaped configuration and allowing the mix to solidify.