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 radon-free ceramic panel includes a mixture including two or more types of stone dust selected from among granite, basalt, limestone, dolomite, elvan, black stone, feldspar, and sandstone, along with waste slag and a non-phenolic adhesive. The ceramic panel is lightweight and has excellent fire resistance, heat insulation, corrosion resistance, water resistance, and ability to act as a bather to radon gas.

A radon-free ceramic panel includes a mixture including two or more types of stone dust selected from among granite, basalt, limestone, dolomite, elvan, black stone, feldspar, and sandstone, along with waste slag and a non-phenolic adhesive. The ceramic panel is lightweight and has excellent fire resistance, heat insulation, corrosion resistance, water resistance, and ability to act as a bather to radon gas.

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.

To provide a prestressed concrete which can be used for non-primary structural members such as general building members by using a chemical stress induced by an expansive material and a mechanical stress induced by a rust-resistant wire together and achieving reduction in weight and suppression of cracking. A prestressed concrete for non-primary structural members is characterized in that a mechanical stress induced by a tensional material and a chemical stress induced by an expansive material for a concrete are introduced and that the tensional material is a rust-resistant continuous fiber reinforcing wire.

A fiber reinforced polymer rebar composition and a method of forming the rebar composition is described. The method includes the steps of feeding a first fiber and a second fiber simultaneously through a preforming guide into a resin impregnator, pulling the fibers through the liquid polymeric resin in the resin impregnator to form a resin-soaked hybrid fiber, and passing the resin-soaked hybrid fiber through a heated stationary die where the resin of the resin-soaked hybrid fiber undergoes polymerization and cross-linking.

An ultrastable cementitious material with nano-molecular veneer makes a cementitious material by blending 29 wt % to 40 wt % of a magnesium oxide dry powder containing 80 wt % to 98 wt % of magnesium oxide based on a final total weight of the cementitious material, with 14 wt % to 18 wt % of a magnesium chloride dissolved in water and reacting to form a liquid suspension, mixing from 2 to 10 minutes, adding a phosphorus-containing material, and allowing the liquid suspension to react into an amorphous phase cementitious material, wherein a portion of the amorphous phase cementitious material grows a plurality of crystals. The plurality of crystals are encapsulated by the amorphous phase cementitious material forming a nano-molecular veneer. A process to make the ultrastable cementitious material. A tile backer board incorporating the ultrastable cementitious material and a process for making the tile backer board.

An ultrastable cementitious material with nano-molecular veneer makes a cementitious material by blending 29 wt % to 40 wt % of a magnesium oxide dry powder containing 80 wt % to 98 wt % of magnesium oxide based on a final total weight of the cementitious material, with 14 wt % to 18 wt % of a magnesium chloride dissolved in water and reacting to form a liquid suspension, mixing from 2 to 10 minutes, adding a phosphorus-containing material, and allowing the liquid suspension to react into an amorphous phase cementitious material, wherein a portion of the amorphous phase cementitious material grows a plurality of crystals. The plurality of crystals are encapsulated by the amorphous phase cementitious material forming a nano-molecular veneer. A process to make the ultrastable cementitious material. A tile backer board incorporating the ultrastable cementitious material and a process for making the tile backer board.

An ultrastable cementitious material with nano-molecular veneer makes a cementitious material by blending 29 wt % to 40 wt % of a magnesium oxide dry powder containing 80 wt % to 98 wt % of magnesium oxide based on a final total weight of the cementitious material, with 14 wt % to 18 wt % of a magnesium chloride dissolved in water and reacting to form a liquid suspension, mixing from 2 to 10 minutes, adding a phosphorus-containing material, and allowing the liquid suspension to react into an amorphous phase cementitious material, wherein a portion of the amorphous phase cementitious material grows a plurality of crystals. The plurality of crystals are encapsulated by the amorphous phase cementitious material forming a nano-molecular veneer. A process to make the ultrastable cementitious material. A tile backer board incorporating the ultrastable cementitious material and a process for making the tile backer board.

The present invention provides a concrete vacuum tube segment for a hyper-speed transportation system using ultra-high performance concrete (UHPC) and a manufacturing method thereof. A concrete vacuum tube segment for a hyper-speed transportation system can be easily manufactured using UHPC, in which shrinkage and structural cracking do not occur due to mixing a binder and a short fiber to secure airtightness on the basis of a maximum fill theory, and accordingly, shrinkage of the concrete vacuum tube segment can be reduced even in a partial-vacuum state in which the magnitude of drying shrinkage is very small and quick drying occurs; when mixing the UHPC, an antifoaming agent is mixed and a circular vacuum pump is used to remove generated entrapped air to minimize the entrapped air; and a capsule-type crack healing material, which is able to repair fine cracks, is compacted to secure airtightness of the concrete vacuum tube segment.