Compositions, methods, and uses of calcium carbonate-based composition are presented. The calcium carbonate-based composition includes a plurality of restructured calcium carbonate particles that has an average size of equal or less than 10 microns in diameter. Preferably, the calcium carbonate-based composition is generated by unstructuring the aragonite using an acid and a chelator and recrystallizing the unstructured aragonite in a customized form. Exemplary aragonite-based compositions include pavement compositions.

Compositions, methods, and uses of calcium carbonate-based composition are presented. The calcium carbonate-based composition includes a plurality of restructured calcium carbonate particles that has an average size of equal or less than 10 microns in diameter. Preferably, the calcium carbonate-based composition is generated by unstructuring the aragonite using an acid and a chelator and recrystallizing the unstructured aragonite in a customized form. Exemplary aragonite-based compositions include pavement compositions.

A low carbon footprint material is used to decrease the carbon dioxide emission for production of a high carbon footprint substance. A method of forming composite materials comprises providing a first high carbon footprint substance; providing a carbon nanomaterial produced with a carbon-footprint of less than 10 unit weight of carbon dioxide (CO.sub.2) emission during production of 1 unit weight of the carbon nanomaterial; and forming a composite comprising the high carbon footprint substance and from 0.001 wt % to 25 wt % of the carbon nanomaterial, wherein the carbon nanomaterial is homogeneously dispersed in the composite to reduce the carbon dioxide emission for producing the composite material relative to the high carbon footprint substance.

A low carbon footprint material is used to decrease the carbon dioxide emission for production of a high carbon footprint substance. A method of forming composite materials comprises providing a first high carbon footprint substance; providing a carbon nanomaterial produced with a carbon-footprint of less than 10 unit weight of carbon dioxide (CO.sub.2) emission during production of 1 unit weight of the carbon nanomaterial; and forming a composite comprising the high carbon footprint substance and from 0.001 wt % to 25 wt % of the carbon nanomaterial, wherein the carbon nanomaterial is homogeneously dispersed in the composite to reduce the carbon dioxide emission for producing the composite material relative to the high carbon footprint substance.

A concrete product set by pouring a concrete slurry includes a concrete mixture, an aluminum-coated colloidal silica admixture, and optionally, at least one reinforcing fiber selected from the group of fibers. As the poured concrete slurry cures, the poured slurry hardens into a composite material product, and the concrete product defines capillary structures that at least in part fill with aluminum-coated silica and lime. Optional graphene oxide may be used in the concrete slurry, in which embodiment the surrounding aggregate and cement is embedded with graphene oxide flakes. A process for placing a jointless and/or fiberless slab made from the concrete product includes preparing a concrete slurry, pouring the concrete slurry onto substrate, and allowing the concrete slurry to cure.

Methods for the dispersion and synthesis of multi-walled carbon nanotube-cement composites with high concentrations of multi-walled carbon nanotubes that do not require chemical dispersion aids or dispersion-enhancing chemical surface functionalization are provided. Also provided are multi-walled carbon nanotube-cement composites made using the methods. Methods for the dispersion and synthesis of carbon nanofiber-cement composites with high concentrations of carbon nanofibers that do not require chemical dispersion aids or dispersion-enhancing chemical surface functionalization are further provided. Also provided are carbon nanofiber-cement composites made using the methods.

Methods for the dispersion and synthesis of multi-walled carbon nanotube-cement composites with high concentrations of multi-walled carbon nanotubes that do not require chemical dispersion aids or dispersion-enhancing chemical surface functionalization are provided. Also provided are multi-walled carbon nanotube-cement composites made using the methods. Methods for the dispersion and synthesis of carbon nanofiber-cement composites with high concentrations of carbon nanofibers that do not require chemical dispersion aids or dispersion-enhancing chemical surface functionalization are further provided. Also provided are carbon nanofiber-cement composites made using the methods.

A system for making an admixture for concrete includes a catalyst and a reactor configured to produce a nanocarbon mixture and a product gas, with the nanocarbon mixture including at least two different types of nanocarbon particles in selected mass percentage ranges. The system also includes a nano-silica-based suspension stabilizer configured for mixing with the nanocarbon mixture to improve the long term stability of the nanocarbon particles in the admixture; and a surfactant configured for mixing with the nanocarbon mixture to facilitate dispersion of the nanocarbon particles in the admixture.

A system for making an admixture for concrete includes a catalyst and a reactor configured to produce a nanocarbon mixture and a product gas, with the nanocarbon mixture including at least two different types of nanocarbon particles in selected mass percentage ranges. The system also includes a nano-silica-based suspension stabilizer configured for mixing with the nanocarbon mixture to improve the long term stability of the nanocarbon particles in the admixture; and a surfactant configured for mixing with the nanocarbon mixture to facilitate dispersion of the nanocarbon particles in the admixture.

A process for making a layered multi-material structural element having controlled mechanical failure characteristics. The process includes the steps of: supplying a cementitious layer and forming a polymer layer on the cementitious layer by additive manufacture such that the polymer layer has a first thickness and the cementitious layer has a second thickness, wherein the polymer layer comprises a polymer and the cementitious layer comprises a cementitious material; and allowing the polymer from the polymer layer to suffuse into the cementitious layer for a period of time to obtain a suffused zone in the cementitious layer such that the suffused zone has a third thickness that is less than half the second thickness.