CPC C04B 28/02 (2013.01) [B28B 1/001 (2013.01); B28B 1/525 (2013.01); B33Y 10/00 (2014.12); B33Y 70/10 (2020.01); B33Y 80/00 (2014.12); C04B 14/062 (2013.01); C04B 14/102 (2013.01); C04B 16/02 (2013.01); C04B 16/0641 (2013.01); C04B 20/008 (2013.01); C04B 28/04 (2013.01); C04B 28/06 (2013.01); C04B 2103/302 (2013.01); C04B 2111/00129 (2013.01); C04B 2111/00181 (2013.01); C04B 2111/50 (2013.01)] | 10 Claims |
1. A printable cementitious composition for additive manufacturing, the composition having a fresh state and a hardened state, wherein in the fresh state the composition is thixotropic, flowable and extrudable in the additive manufacturing process and has a flowability factor of greater than or equal to about 1.1 to less than or equal to about 1.7 and in the hardened state, the composition exhibits strain hardening and has a uniaxial tensile strength of greater than or equal to about 2.5 MPa, a tensile strain capacity of greater than or equal to about 2.5%, and a compressive strength at 100 hours of greater than or equal to about 20 MPa, wherein the composition comprises Portland cement, a calcium aluminate cement, a fine aggregate, water, a high range water reducing agent (HRWRA), a polymeric fiber, and the printable cementitious composition further comprises:
microsilica at greater than or equal to about 2 mass % to less than or equal to about 30 mass % of the total mass of the composition,
silica flour present at greater than or equal to about 0.1 mass % to less than or equal to about 5 mass % of the total mass of the composition, and
attapulgite nanoclay greater than or equal to 0.5 mass % to less than or equal to about 3 mass % of the total mass of the composition.
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