Construction Research & Technology Gmbh

Bernhard Sachsenhauser

Peter Schwesig

Massimo Bandiera

Klaus Lorenz

Tatiana Mitkina

Wolfgang Seidl

Farra Ramzi

Sebastien Dhers

Davide Carnelli

Johanna Parks

Matthias Klein

Kai Steffen Weldert

Jasveer Ramroo Beni

Sabine Himmelein

Sebastian Dhers

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; 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), 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.

Construction composition

A cement-reduced construction composition comprises a) a cementitious binder comprising one or more calcium silicate mineral phases and one or more calcium aluminate mineral phases, and having a Blaine surface area of at least 3800 cm/g; b) a fine material having a Dv90 of less than 200 μm, selected from alkali-activatable binders, rock powders and inorganic pigments, or mixtures thereof; c) optionally, an extraneous aluminate source; d) a sulfate source; and e) a polyol. The composition contains a controlled amount of available aluminate, calculated as Al(OH), from the calcium aluminate mineral phases plus the optional extraneous aluminate source; and the molar ratio of total available aluminate to sulfate is 0.4 to 2.0. The construction composition further comprises f) an ettringite formation controller and g) a co-retarder. The cement-reduced construction composition is a reduced carbon footprint construction composition and exhibits high early strength, high final strength, sufficient open time, high durability, and reduced shrinkage compared to ordinary Portland cement based mixes.

Cement-reduced construction composition

A limestone calcined clay cement construction composition comprises a) a cementitious binder comprising one or more calcium silicate mineral phases and one or more calcium aluminate mineral phases, and having a Blaine surface area of at least 3800 cm/g; b) a supplementary cementitious material having a Dv90 of less than 200 μm comprising (b-1) a calcined clay material and (b-2) a carbonate rock powder in a weight ratio of (b-1) to (b-2) in the range of 0.5 to 2; c) optionally, an extraneous aluminate source; d) a sulfate source; and e) a polyol. The composition contains a controlled amount of available aluminate, calculated as Al(OH), from the calcium aluminate mineral phases plus the optional extraneous aluminate source; and the molar ratio of total available aluminate to sulfate is 0.4 to 2.0. The construction composition further comprises f) an ettringite formation controller. The limestone calcined clay cement construction composition is a reduced carbon footprint composition and exhibits high early strength, high final strength, sufficient open time and high durability.

Limestone calcined clay cement (LC3) construction composition

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Trostberg, Germany

Bernhard Sachsenhauser