摘要:
A construction composition comprises a) a cementitious binder comprising one or more calcium silicate mineral phases and one or more calcium aluminate mineral phases; b) optionally, an extraneous aluminate source; c) a sulfate source; d) an ettringite formation controller comprising (i) glyoxylic acid, a glyoxylic acid salt and/or a glyoxylic acid derivative; and (ii) at least one of a borate source and a carbonate source, wherein the carbonate source is selected from inorganic carbonates having an aqueous solubility of 0.1 g·L−1 or more, organic carbonates, and mixtures thereof; and e) a polyol in an amount of 0.2 to 2.5 wt.-%, relative to the amount of cementitious binder a). The composition contains 0.05 to 0.2 mol of total available aluminate, calculated as Al(OH)4−, from the calcium aluminate mineral phases plus the optional extraneous aluminate source, per 100 g of cementitious binder a); and the molar ratio of total available aluminate to sulfate is 0.4 to 2.0. The construction composition exhibits high early strength and sufficient open time. The advantageous effects are readily achievable for a variety of cements with varying elemental compositions.
摘要:
A proposal is made for a cementitious system which comprises accelerator particles coated with crosslinked shellac, for the use as an additive component which comprises the accelerator particles coated with crosslinked shellac, and for a cement slurry which comprises the cementitious system and water.