Provided herein are compositions, methods, and systems related to 3D printing a reactive vaterite cement composition, comprising feeding a composition comprising reactive vaterite cement through a 3D printing machine; printing a 3D printed reactive vaterite cement product; and curing the 3D printed reactive vaterite cement product by transforming reactive vaterite cement in the 3D printed reactive vaterite cement product to aragonite and/or calcite during and/or after the curing.

Provided herein are compositions, methods, and systems related to 3D printing a reactive vaterite cement composition, comprising feeding a composition comprising reactive vaterite cement through a 3D printing machine; printing a 3D printed reactive vaterite cement product; and curing the 3D printed reactive vaterite cement product by transforming reactive vaterite cement in the 3D printed reactive vaterite cement product to aragonite and/or calcite during and/or after the curing.

A method of forming a lightweight polished concrete and the resulting composition. Calcium sulfoaluminate (CSA) cement and specialized grout may be added to an amount of water in a mixer. The CSA cement, specialized grout, and water may be blended to a smooth consistency. Lightweight aggregates (LWA) may be added to the blended CSA cement, specialized grout, and water to form a mixture. The mixture may be poured over a fiberglass rebar, vibrated, screeded, and allowed to set. The set mixture may be smoothed with float blades. The smoothed mixture may be hardened with metal blades, such that the hardened mixture becomes reflective. A concrete densifier may be applied to the hardened mixture to form the lightweight polished concrete. Optionally, one or more saw cuts may be formed in the lightweight polished concrete and a coating to may be applied to fill the one or more saw cuts.

A method of forming a lightweight concrete block and the resulting structure. Calcium sulfoaluminate (CSA) cement and specialized grout maybe added to an amount of water in a mixer. The CSA cement, specialized grout, and water may be blended to a smooth consistency. Lightweight aggregates (LWA) maybe added to form a mixture. The mixture may be poured into a mold, allowed the mixture to cure, and removed from the mold to form the lightweight concrete block. The lightweight concrete block may have a first side and a second side joined by a plurality of interposing walls, the interposing walls defining one or more inner cavities and one or more outer cavities. The lightweight concrete block may have features that allow for the insertion of fiberglass rebar to aide in stacking and filling to form a wall.

A method of forming a lightweight concrete comprising lightweight aggregates (LWA) made from recycled materials and the resulting composition. The lightweight concrete may be formed by adding calcium sulfoaluminate (CSA) cement and a specialized grout to an amount of water in a mixer, wherein a ratio of the water to the CSA cement is 1 quart to every 10 lbs of CSA cement. The CSA cement, specialized grout, and water may be blended to a smooth consistency. LWA may be added to the blended CSA cement, specialized grout, and water, wherein a ratio of the CSA cement to LWA is 60/40 by weight. The mixture of LWA, CSA cement, specialized grout, and water may be poured over a fiberglass rebar. The mixture may be allowed to cure and before being densified with a lithium densifier.

A method of slip forming a concrete structure can include using a first slip form mold that travels along a path to form a portion of a concrete structure by delivering a first flow of concrete into the first mold through a first hopper. The first hopper can be configured to receive the first flow of concrete. The portion of the concrete structure can be modified using a second slip form mold different from the first mold by advancing the second mold along the concrete structure and, while advancing the second mold, delivering a second flow of concrete into the second mold through a second hopper that is configured to receive the second flow of concrete.

The invention discloses a special equipment and a method for surface microcrystallization of cementitious materials. The specialized equipment includes a vibrator, a vibration signal generator, a power amplifier and a vibration transmitting body. A signal output terminal of the vibration signal generator is connected to a signal input terminal of the power amplifier, a signal output terminal of the power amplifier is connected to a signal input terminal of the vibrator, the vibrator is connected to the vibration transmitting body, and the vibration transmitting body is to be in contact with the cement product after initial setting. The surface microcrystallization method for cement product: after the casting and before the final setting of the cement product, vibration is applied to its outer or inner surface, the vibration frequency is greater than or equal to 1 KHz, and the vibration time is greater than or equal to 5 minutes. The surface layer of the cement product prepared by the present invention forms a structured layer with a certain thickness, high density, low permeability and relatively uniform surface coverage of granular crystal or gel phase, so that the cement product has excellent anti-aging performance.

One aspect of the present invention pertains to methods of forming concrete structures. Another aspect of the present invention pertains to systems for forming concrete structures. Another aspect of the present invention pertains to devices forming concrete structures.

One aspect of the present invention pertains to methods of forming concrete structures. Another aspect of the present invention pertains to systems for forming concrete structures. Another aspect of the present invention pertains to devices forming concrete structures.

This method for manufacturing a railway track support comprising a plurality of prefabricated elements (28) comprises the following successive steps: providing, in a production zone (16) for prefabricated elements (28) located near an installation zone (14), a movable insertion machine (52) configured to arrange at least one insert (34) in a fresh concrete block, the production zone being separate from the installation zone; pouring and shaping fresh concrete in order to form individual fresh concrete blocks having predetermined dimensions; arranging at least one insert in each fresh concrete block using the movable insertion machine (52); drying the fresh concrete blocks to obtain the prefabricated elements (28).