Patent ID: 11919812
Assignee: H2CONNECT 2 GMBH
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  B  Y | IPC B  C

Claim 0:
1. A cementitious mixture for a 3D printer which comprises:

a) from 10% to 70% by weight of a cement or hydraulic binder,
b) from 0.5% to 25% by weight with respect to the total weight of the cementitious mixture of a natural or artificial latent hydraulic addition having a specific surface ranging from 3,500 cm2/g to 6,500 cm2/g, determined according to the Blaine method according to EN 196-6:2010,
c) from 10% to 50% by weight of a filler,
d) aggregates,
e) additives,
f) water, wherein:

component c) conforms with standard UNI EN 12620-1: 2008 and is selected from calcareous, silica or silico-calcareous fillers, and mixtures thereof having a particle size wherein at least 90% by weight of the filler passes through an 0.063 mm sieve;
component d) is present in a quantity ranging from 10% to 80% by weight with respect to the total weight of the cementitious mixture, and comprises calcareous, silica or silico-calcareous aggregates, in accordance with standard UNI EN 206: 2014, alone or mixed with each other, having a particle size with a maximum diameter lower than 1 mm, said component d) comprising an aggregate fraction having a particle size with a diameter greater than 0.2 mm and an aggregate fraction having a particle size with a diameter less than or equal to 0.2 mm and such that less than 2% by weight passes through a sieve of 0.063 mm;
component e) comprises from 0.01% to 1.5% by weight of a superfluidifying additive selected from superfluidifying acrylic-based polycarboxylates, liposulfonates, naphthalene sulfonates, melamine or vinyl compounds from 0.01% to 5.0% by weight of a rheology modifying additive; from 0.01% to 2.0% by weight of modified starch; from 0.0% to 1.0% by weight of a shrinkage reducing agent: from 0.05% to 0.5% of a hydrophobic additive selected from silicone or silane derivatives and mixtures thereof,
said cementitious mixture having a viscosity value ranging from 80,000 Pa·s to 150,000 Pa·s, measured at a shear rate of 0.01 s−1 and at a temperature of 20° C.,
wherein the weight ratio between the binder and the aggregate ranges from 0.5 to 2.0, the binder comprising components a) and b) of the cementitious mixture.