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).

The invention comprises a method of curing concrete. The method comprises placing a concrete cylinder in an insulated container having a sufficient quantity of water therein so that the concrete cylinder is submerged in and surrounded by the water and selectively adding heat to the quantity of water in an insulated container, so that the temperature of the quantity of water follows a predetermined temperature profile.

The invention comprises a method of curing concrete. The method comprises placing a concrete cylinder in an insulated container having a sufficient quantity of water therein so that the concrete cylinder is submerged in and surrounded by the water and selectively adding heat to the quantity of water in an insulated container, so that the temperature of the quantity of water follows a predetermined temperature profile.

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 US 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 404015 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 US 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 404015 cm) with mechanically activated cement and performance complying with the standards.

The invention comprises a method of curing concrete. The method comprises placing a concrete cylinder in an insulated container having a sufficient quantity of water therein so that the concrete cylinder is submerged in and surrounded by the water and selectively adding heat to the quantity of water in an insulated container, so that the temperature of the quantity of water follows a predetermined temperature profile. Apparatus for performing the method is also disclosed.

The invention comprises a method of curing concrete. The method comprises placing a concrete cylinder in an insulated container having a sufficient quantity of water therein so that the concrete cylinder is submerged in and surrounded by the water and selectively adding heat to the quantity of water in an insulated container, so that the temperature of the quantity of water follows a predetermined temperature profile. Apparatus for performing the method is also disclosed.

The invention comprises a method of curing concrete. The method comprises placing a concrete cylinder in an insulated container having a sufficient quantity of water therein so that the concrete cylinder is submerged in and surrounded by the water and selectively adding heat to the quantity of water in an insulated container, so that the temperature of the quantity of water follows a predetermined temperature profile.

The invention comprises a method of curing concrete. The method comprises placing a concrete cylinder in an insulated container having a sufficient quantity of water therein so that the concrete cylinder is submerged in and surrounded by the water and selectively adding heat to the quantity of water in an insulated container, so that the temperature of the quantity of water follows a predetermined temperature profile.

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.