Wear layer for working floors - comprises sand-limestone aggregate and binder contg. alpha-hemi:hydrate, low-alumina cement, plastic dispersion, fine silica and additives

摘要

Wear layer (I) for working floors consists of a binder contg. cement, gypsum, plastic dispersion and the usual additives, and an aggregate contg. silica sand and powdered limestone, and forms a pumpable, self-levelling mortar; the novelty is (a) that the binder consists of 40-60 pts. wt. alpha-hemihydrate (II), 40-60 pts. wt. low-alumina cement (III), 10-20 pts. wt. plastic dispersion powder, 3-10 wt.% finely divided silica (IV) and up to 3 wt.% foam suppressant, stabiliser, liquefier, retarder and/or accelerator and (b) the amt. of aggregate is 0.6-2 pts. wt. per 1 pt. wt. binder. (II) is produced from gypsum from flue gas desulphurisation, with 98% of the particles below 40 microns, (III) is Portland cement F-HS (DIN 1164) with C3A below 3% and (IV) is the waste prod. (micro-silica) from ferrosilicon prodn. and/or the HCl-digestion prod. from melting chamber granules; other additives are MF resins, naphthalenesulphonic acid-formaldehyde resins, lignin sulphonates, hydroxycarboxylic acids, amino acids, protein hydrolysates, animal glue and alkali sulphates; stabiliser is a synthetic polysaccharide, pref., xanthan gum; another aggregate material is swollen clay grit with grain size 0-1.5 mm. USE/ADVANTAGE - The invention provides a heavy-duty wear layer which will even withstand the passage of fork-lift trucks, etc. without undue wear on the vehicle tyres; the material can be applied by pumping, is self-levelling, and meets all the normal requirements w.r.t. strength properties, setting characteristics, water-resistance, material costs, etc.