The invention relates to processes for making improved ultra-high performance concrete with plasma-treated inclusions and articles made from the same. The invention includes a process for producing silicon carbide and multiwalled carbon nanotubes by heating agricultural waste husks in an inert atmosphere to a temperature higher than 1300 degrees C. to obtain a mixture containing silicon carbide and MWCNTs, and treating the mixture to extract the silicon carbide and MWCNTs for use as microinclusions in ultra high performance concrete.

The present invention refers to a mechanically activated cementitious composite for stopping the impact of firearms, which involved the designing of mixes of Portland Composite Cement PCC mechanically activated through high energy mechanical milling (HEM) with other ingredients, such as: Ordinary PCC Cement, fine sand, fibers, and polymeric additives, among other compounds, to prepare high-performance composite walls capable of stopping several calibers up to type 50 (typically loaded in Barret rifles). In accordance with Mexican and U.S. Standards for ballistic tests, which entail the approval of the concrete ballistic-resistant wall as long as it resists one impact with a 50 caliber Barret, the present invention allows the construction of composite walls (with dimensions of 40×40×15 cm) with mechanically activated cement and performance complying with the standards.

The present invention refers to a mechanically activated cementitious composite for stopping the impact of firearms, which involved the designing of mixes of Portland Composite Cement PCC mechanically activated through high energy mechanical milling (HEM) with other ingredients, such as: Ordinary PCC Cement, fine sand, fibers, and polymeric additives, among other compounds, to prepare high-performance composite walls capable of stopping several calibers up to type 50 (typically loaded in Barret rifles). In accordance with Mexican and U.S. Standards for ballistic tests, which entail the approval of the concrete ballistic-resistant wall as long as it resists one impact with a 50 caliber Barret, the present invention allows the construction of composite walls (with dimensions of 40×40×15 cm) with mechanically activated cement and performance complying with the standards.

The invention relates to the use of a multi-component composition comprising A) a polyol component (A) comprising at least one polyol and water, B) a hardener component (B) comprising at least one polyisocyanate, and C) a solid component (C) comprising a hydraulic binder and one or more aggregates, as an early water resistant construction or repair material for constructing, repairing or refurbishing component parts, wherein the mixed and applied multi-component composition is immersed in water not later than 8 hours, preferably not later than 2 h, after application. The use as an early water resistant construction or repair material is especially suitable for component parts, which are in contact with water during operation such as offshore wind energy plants or water retaining systems, e.g. pipelines.

The invention relates to the use of a multi-component composition comprising A) a polyol component (A) comprising at least one polyol and water, B) a hardener component (B) comprising at least one polyisocyanate, and C) a solid component (C) comprising a hydraulic binder and one or more aggregates, as an early water resistant construction or repair material for constructing, repairing or refurbishing component parts, wherein the mixed and applied multi-component composition is immersed in water not later than 8 hours, preferably not later than 2 h, after application. The use as an early water resistant construction or repair material is especially suitable for component parts, which are in contact with water during operation such as offshore wind energy plants or water retaining systems, e.g. pipelines.

The invention relates to a method for activation of concrete mixing water. The method includes preliminary action on the mixing water in continuous flow by pulsed high-voltage electrohydraulic discharges with supply DC voltage from 500 V to 5000 V at a pulse frequency from 2 Hz to 10,000 Hz and a current from 0.1 A to 10 A on electrodes of copper and/or iron and/or titanium. Then the water is treated in a mechanical and/or ultrasonic cavitator in the developed cavitation mode and at a water pressure from 0.8 atm to 6 atm without addition of plasticizers and/or surface-active agents.

The invention relates to a method for activation of concrete mixing water. The method includes preliminary action on the mixing water in continuous flow by pulsed high-voltage electrohydraulic discharges with supply DC voltage from 500 V to 5000 at a pulse frequency from 2 Hz to 10,000 Hz and a current from 0.1 A to 10 A on electrodes of copper and/or iron and/or titanium. Then the water is treated in a mechanical and/or ultrasonic cavitator in the developed cavitation mode and at a water pressure from 0.8 atm to 6 atm without addition of plasticizers and/or surface-active agents.

A method for forming cement-based cementitious material includes: pouring a cement paste into a mold; applying an electrical current to the cement paste to perform an electro-osmotic reaction; and transferring the reacted cement paste into a water tank for curing, thereby obtaining a functionally graded cement-based cementitious material. A pair of electrodes is placed in the mold and connected to an external power source. The compressive strength of the functionally graded cement-based cementitious material in the middle is lower than that at either of both ends.

A method for forming cement-based cementitious material includes: pouring a cement paste into a mold; applying an electrical current to the cement paste to perform an electro-osmotic reaction; and transferring the reacted cement paste into a water tank for curing, thereby obtaining a functionally graded cement-based cementitious material. A pair of electrodes is placed in the mold and connected to an external power source. The compressive strength of the functionally graded cement-based cementitious material in the middle is lower than that at either of both ends.

A cement composition is disclosed containing: cement; cellulose nanofibers; and water, wherein a mass ratio of the water to cement is 0.4 or less. The cement is preferably Portland cement. It is preferred that the Portland cement is high-early-strength Portland cement, and that a mass ratio of fine aggregate to the high-early-strength Portland cement is 2.0 or less. A unit amount of cellulose nanofibers in the cement composition can be 0.1 kg/m.sup.3 to 15 kg/m.sup.3 Furthermore, a hardened body of the cement composition is disclosed, wherein a ratio of a splitting tensile strength of the hardened body at a material age of 91 days obtained by curing in air, to the splitting tensile strength of the hardened body at the material age if 91 days obtained by curing in water is 0.90 or more and 1.10 or less, the splitting tensile strength being measured in accordance with JIS-A-1113 (2006).