Abstract: The invention concerns a method for establishing a plug inside a main pipe, in particular a vertically or slantingly arranged pipe, where said pipe has firs and second ends, and where the plug is arranged inside the pipe at a distance from said first and second ends, where a liquid surface is provided at least inside the pipe, below the level at which it is desirable to establish the plug, where a buoyant layer is established on top of said liquid surface, and where a plug material is placed on top of ‘said buoyant layer as well as a plug established according to the method. The buoyant layer can be granular, liquid or solid material. The plug is made of foam material, expandable material or cement-based material such as concrete.

Abstract: The present invention relates to a tower foundation system (30) comprising a foundation (32) for a bottom section (36) of a tower, which bottom section (36) is to be connected to the upper part of the foundation (32), wherein the bottom section (36) is cast into the foundation (32) with an ultra high performance grout (42).

Abstract: 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 Na.sub.2 O 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.