A masonry unit composed of hydraulic lime binder and hemp hurd in a hydraulic lime binder:hemp hurd ratio of 1.4:1 to 1.6:1, wherein the hydraulic lime binder includes less than 1% by weight of each of potassium oxide (K.sub.2O), sodium oxide (Na.sub.2O), and sulfur trioxide (SO.sub.3), and wherein the masonry unit has a front surface, a rear surface, a first side surface and an opposing second side surface. The front surface has a larger surface area than the rear surface, and the first side surface and second side surface each include a shoulder. A biocomposite material, settable formulations, and method of preparing a masonry unit are also described.

A masonry unit composed of hydraulic lime binder and hemp hurd in a hydraulic lime binder:hemp hurd ratio of 1.4:1 to 1.6:1, wherein the hydraulic lime binder includes less than 1% by weight of each of potassium oxide (K.sub.2O), sodium oxide (Na.sub.2O), and sulfur trioxide (SO.sub.3), and wherein the masonry unit has a front surface, a rear surface, a first side surface and an opposing second side surface. The front surface has a larger surface area than the rear surface, and the first side surface and second side surface each include a shoulder. A biocomposite material, settable formulations, and method of preparing a masonry unit are also described.

A method of forming a cured cement or concrete object is described that includes printing a carbonatable material and a CO.sub.2 source; and hardening the printed carbonatable material by a carbonation reaction. Associated cured and uncured objects, as well as related methods are also described.

A method of forming a cured cement or concrete object is described that includes printing a carbonatable material and a CO.sub.2 source; and hardening the printed carbonatable material by a carbonation reaction. Associated cured and uncured objects, as well as related methods are also described.

Various embodiments include cementitious compositions with low levels of embodied greenhouse gas emissions, in particular carbon dioxide, as a result of its production and/or use compared to conventional cementitious materials, such as portland cement. Various embodiments include any cementitious material or materials with low embodied carbon, as well as any material produced using this cement.

Various embodiments include cementitious compositions with low levels of embodied greenhouse gas emissions, in particular carbon dioxide, as a result of its production and/or use compared to conventional cementitious materials, such as portland cement. Various embodiments include any cementitious material or materials with low embodied carbon, as well as any material produced using this cement.

Carbon-sequestering composite mixture and methods of carbon sequestration utilizing an aquatic composite structure composed of the composite mixture. The mixture comprises a composite, nanoparticles, and binder. The nanoparticles impact the pore size of the composite mixture, thereby positively impacting the carbon sequestration properties of the mixture. By emplacing an aquatic composite structure composed of such a mixture in an aquatic environment such that it provides erosion mitigation, simultaneous environmental protection effects may be achieved. Further, the binder positively encourages natural ecological growth on the aquatic composite structure, thereby encouraging environmental restoration and encouraging naturally-occurring carbon sequestration from the ecological growth, potentially well past the point at which the aquatic composite structure is unable to continue to sequester carbon.

Carbon-sequestering composite mixture and methods of carbon sequestration utilizing an aquatic composite structure composed of the composite mixture. The mixture comprises a composite, nanoparticles, and binder. The nanoparticles impact the pore size of the composite mixture, thereby positively impacting the carbon sequestration properties of the mixture. By emplacing an aquatic composite structure composed of such a mixture in an aquatic environment such that it provides erosion mitigation, simultaneous environmental protection effects may be achieved. Further, the binder positively encourages natural ecological growth on the aquatic composite structure, thereby encouraging environmental restoration and encouraging naturally-occurring carbon sequestration from the ecological growth, potentially well past the point at which the aquatic composite structure is unable to continue to sequester carbon.

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.