US-12623966-B2 - Ternary hydraulic binder composition

US12623966B2US 12623966 B2US12623966 B2US 12623966B2US-12623966-B2

Abstract

A ternary hydraulic binder composition including the mineralogical compound C 4 A 3 $ (ye'elimite) and a member selected from the group consisting of gypsum, calcium sulfate hemihydrate, anhydrite and mixtures thereof (collectively named C$H x with x being a rational number from 0 to 2), and optionally C 2 S (belite), including an added content of the mineralogical compound C 12 A 7 (dodecacalcium heptaaluminate). Moreover, it suggests a process for the manufacture thereof, a process for the manufacture of a construction chemical composition including water, and the use of the ternary composition in construction chemical compositions including knifing fillers, screeds, and repair mortars, tile adhesives, tiling grouts, plasters, base coats and sealings.

Inventors

Christina KRAEMER
Werner Stohr
Alexander Dressen
Wilhelm FUETTERER
Stephan RUDOLF
Guenter GOTH
Torsten Mueller
Yvonne SCHAEPERS
Alexander Ehle
Ulrich BAEURLE

Assignees

SIKA TECHNOLOGY AG

Dates

Publication Date: 20260512
Application Date: 20211223
Priority Date: 20201223

Claims (5)

1 . A method for accelerating the setting and hardening, improving the hydration performance, or reducing the shrinkage of a binder composition comprising: 24-64% b.wt. of a mineralogical compound C 4 A 3 $, 6-40% b.wt. of C$H x , wherein C$H x is a member selected from the group consisting of gypsum, calcium sulfate hemihydrate, anhydrite and mixtures thereof and wherein x being a rational number from 0 to 2, 0-5% b.wt. of a mineralogical compound C 12 A 7 , and optionally C 2 S, the method comprising incorporating an additional amount of 0.2-20% b.wt. of the mineralogical compound C 12 A 7 into the binder composition.
2 . The method of claim 1 , wherein the mineralogical compound C 12 A 7 improves the hydration performance of the binder composition.
3 . The method of claim 1 , wherein the mineralogical compound C 12 A 7 reduces the shrinkage of the binder composition.
4 . The method of claim 1 , wherein the mineralogical compound C 12 A 7 accelerates the setting and hardening of the binder composition.
5 . The method of claim 1 , wherein the binder composition is present in the form of a CSA cement.

Description

The present invention relates to a ternary hydraulic binder composition comprising ye'elimte and calcium sulfate, and optionally belite, characterized by an added content of the mineralogical compound C12A7 (dodecacalcium heptaaluminate). Moreover, it relates to a process for the manufacture thereof, a process for the manufacture of a construction chemical composition including water, and the use of the ternary composition in construction chemical compositions comprising knifing fillers, screeds, and repair mortars, tile adhesives, tiling grouts, plasters, base coats and sealings. Portland cement was first mentioned in British patent BP 5022 (Joseph Aspdin, 1824) and has since been continuously further developed. Modern Portland cement contains about 70% by weight of CaO+MgO, about 20% by weight of SiO2 and about 10% by weight of Al2O3+Fe2O3. Portland cement hardens hydraulically. On the downside, the manufacture of Portland cement has a large environmental impact, i.e. a large CO2 footprint. Calcium aluminate cement (“CAS cement”) predominantly comprises CaO·Al2O3. It can be obtained by melting calcium oxide (CaO) or limestone (CaCO3) and bauxite or aluminate together. Calcium aluminate cement comprises about 20 to 40% by weight of CaO, up to about 5% by weight of SiO2, about 35 to 80% by weight of Al2O3 and up to about 20% by weight of Fe2O3. Calcium aluminate cements are defined according to DIN EN 14647 (January 2006). Calcium aluminate cement has a smaller environmental impact, i.e. a smaller CO2 footprint than Portland cement. Calcium Sulfoaluminate cement (“CSA cement”) is distinguished from Portland cement by fast bonding, fast strength development and shrinkage reduction. CSA cement was used for decades as a binder in concrete for bridges, airport runways, road repair, and many other applications where a quick setting is required. CSA cement is also used in dry mortars for self-levelling floors, levelling compounds, casting mortars, tile adhesives, grouts, etc. In contrast to Portland cement, CSA cement has a smaller environmental impact, i.e. a smaller CO2 footprint, because it is calcinated at a lower temperature than Portland cement, i.e. at 1100 to 1300° C. Moreover, CSA cement is less alkaline than Portland cement. However, setting time, strength development and final strength of CSA cement still leave room for further improvement. In order to accelerate the setting and hardening of CSA cement, lithium salts are often employed. However, lithium is globally in short supply, the manufacture thereof is environmentally critical and work conditions are humanly questionable, at best. There exists a need to reduce or completely avoid the addition of lithium required for acceleration. In Cement Chemist Notation (CCN), the constituents of mineralogical compounds are generally mentioned in their oxide form. “C” stands for CaO, “A” stand for Al2O3, “S” stands for SiO2, “$” hereinbelow stands for SO3, and “H” stands for H2O. CSA cement contains the mineralogical compound C4A3$ (ye'elimite) and calcium sulfate (gypsum, calcium sulfate hemihydrate, and/or anhydrite (hereinbelow collectively called C$Hx with x being a rational number from 0 to 2)). It may also contain substantial amounts of C2S (belite). Upon contact with water, it hydraulically hardens mainly forming ettringite (C6A$3H32). U.S. Pat. No. 6,730,162 B1, corresponding to WO 01/74737 A1, discloses (abstract): a method of preparing a hydraulic binder wherein at least the following two binders are mixed together: a) a first hydraulic binder having as one of its main components the mineral compound C4A3$; and b) a sulfate second binder based on calcium sulfate hemihydrate and/or anhydrite obtained by applying heat treatment to gypsum. It also provides a binder comprising amongst its main components: a) a mineral compound C4A3$; and b) a compound comprising a hemihydrate of calcium sulfate of a or ß form and of general formula CaSO4·½H2O and/or an anhydrite of Ill form of general formula CaSO4·εH2O with & is in the range 0 to 0.5, preferably in the range 0.06 to 0.11, or an anhydrite of II form of formula CaSO4. DE 102010034874 A1 discloses (abstract): a mineral binder composition, containing A) at least one pozzolanically or latent hydraulically setting Material, B) at least one calcium sulfoaluminate and C) at least one calcium sulfate hemihydrate and/or calcium sulfate anhydrite, where the weight ratio of component A) to component B) from 5:1 to 1:10 and the weight ratio of component B) to component C) is from 50:1 to 1:2, as well as construction chemical products containing a corresponding mineral binder composition. WO 2012/127066 A1 discloses (abstract): a dry cement composition for preparing a wet coating formulation consisting of mortar or concrete, enabling, in particular, the creation of thick non-efflorescent inorganic coatings without adversely affecting the other properties required for the corresponding wet formulation, namely handines