A method for the construction of a data center, includes (a) providing a fresh concrete composition including a paste that includes a hydraulic binder, a mineral addition and water, the paste being present in a mixture with sand and aggregates, whereby the paste is present in the concrete composition in a volume of <320 L/m.sup.3 and/or the solid volume fraction of said paste is >50 vol.-% and (b) placing the fresh concrete composition so as to build walls, a floor and/or a ceiling of the data center, which are intended to surround the individual components of computer systems, which are housed in the data center.

The invention relates to a cement powder blend comprising, based on total weight 45-90 wt. % non-Portland cement; 5-30 wt. % polyvinylalcohol; the blend having a content of 0-25 wt. % siliceous fly ash; and 0-25 wt. % limestone, preferably polyvinylalcohol having a size distribution with D.sub.10=170-270 μm, D.sub.50=370-450 μm, D.sub.90=690-850 μm and D.sub.100=1000-1300 μm. Further the invention relates to concrete composed of a blend according to the invention and aggregate.

A method for the preparation of concretes with improved wear resistance. The method involves the use of colloidal silica, which is added to a concrete mixture after mixing, in conjunction with a concrete cutter, which is added to the concrete mixture after the addition of the colloidal silica.

In various embodiments, a process is described for the preparation of a concrete mixture in a Ready-mix or for an installation. A quantity of amorphous silica is added with an average particle size in the range of from about 1 to about 55 nanometers and/or wherein the surface area of the particles of the amorphous silica is in the range of from about 300 to about 900 m2/g. The amorphous silica may be added in colloidal form or otherwise, and is added at a particular stage to ensure efficacy.

A composition including: at least one waterbased polyurethane dispersion containing ethylene oxide units; at least one cement; and at least one mineral filler. The composition can be mixed and applied without coagulation of the polyurethane dispersion. Upon curing, it has a high strength and good adhesion properties, with surprisingly low shrinkage and most surprisingly good water impermeability properties. It is particularly suitable for the use as repair mortar, waterproofing mortar or screed mortar.

In various embodiments, a process is described for the preparation of a concrete mixture in a Ready-mix or for an installation. A quantity of amorphous silica is added with an average particle size in the range of from about 1 to about 55 nanometers and/or wherein the surface area of the particles of the amorphous silica is in the range of from about 50 to about 900 m2/g. The amorphous silica may be added in colloidal form or otherwise, and is added at a particular stage to ensure efficacy.

Compositions and methods for producing materials for construction and for dust control utilizing enzyme producing cells, an amount of a nitrogen source such as urea, and an amount of calcium such as calcium chloride. Calcium contributes to the formation of calcium carbonate which creates a solid structure, layer or shield. One or more compositions containing components of the invention can be sprayed or otherwise applied to surfaces for erosion control, foundation support, prevention of sink hole formation, prevention of dust formation, or other applications. Ammonia, water and other by-products of the process can be recycled and re-utilized for the same or other purposes including, for example, as fertilizers and energy sources, or independently fermented from selectively cultivated microorganisms.