Provided herein are cementitious materials, for example, a crack-resistant cementitious mortar. The cementitious materials are a mixture of cement, at least one recycled fiber reinforcement material, a recycled aggregate material, and water. Also provided is a method for increasing the crack-resistance of a cementitious material by replacing the sand in a cement mortar with a recycled aggregate material and adding at least one recycled fiber reinforcement material and a volume of water.

A concrete construction (100) made by 3D concrete printing that contains: two or more layers (102, 106) of cementitious material extruded one above the other, and at least one elongated steel element (104, 108) reinforcing at least one of the two or more layers. The elongated steel element (104, 108) is provided with a first crimp. Due to the crimp, a good anchorage in concrete is obtained and the anchorage force is predictable, since the standard deviation of the anchorage force is very small. The elongated steel element can be a single steel wire with a diameter D, the amplitude of the crimp ranges from 1.05×D to 5.0×D. The elongated steel element can also be a steel with steel filaments having a maximum diameter d. The amplitude of the crimp ranges from 1.05×d to 5.0×d.

A concrete construction (100) made by 3D concrete printing that contains: two or more layers (102, 106) of cementitious material extruded one above the other, and at least one elongated steel element (104, 108) reinforcing at least one of the two or more layers. The elongated steel element (104, 108) is provided with a first crimp. Due to the crimp, a good anchorage in concrete is obtained and the anchorage force is predictable, since the standard deviation of the anchorage force is very small. The elongated steel element can be a single steel wire with a diameter D, the amplitude of the crimp ranges from 1.05×D to 5.0×D. The elongated steel element can also be a steel with steel filaments having a maximum diameter d. The amplitude of the crimp ranges from 1.05×d to 5.0×d.

A high modulus composite part is disclosed comprising a polymer resin; and a plurality of high-performance unidirectional glass fibers. The high-performance unidirectional glass fibers have an elastic modulus of at least 89 GPa and a tensile strength of at least 4,000 MPa, according to ASTM D2343-09. The composite part comprises a fiber weight fraction (FWF) of no more than 88% and an elastic modulus of at least 60 GPa, according to ASTM D7205.

A high modulus composite part is disclosed comprising a polymer resin; and a plurality of high-performance unidirectional glass fibers. The high-performance unidirectional glass fibers have an elastic modulus of at least 89 GPa and a tensile strength of at least 4,000 MPa, according to ASTM D2343-09. The composite part comprises a fiber weight fraction (FWF) of no more than 88% and an elastic modulus of at least 60 GPa, according to ASTM D7205.

The corrosion-preventing additive for reinforced concrete is a concrete additive for preventing corrosion of steel rebars in steel-reinforced concrete. The corrosion-preventing additive is a solution with an organic solvent, the solute being either gallic acid (3,4.5-trihydroxybenzoic acid), at least one ester of gallic acid, or combinations thereof. The weight-to-volume concentration of the solute to the organic solvent may be between 1% and 10% w/v. Reinforced concrete may be made using the corrosion-preventing additive by mixing the corrosion-preventing additive with a conventional concrete mixture (i.e., a mixture of an aggregate, water, and cement), with at least one steel rebar being embedded in the mixture, similar to conventional steel rebar reinforced concrete. The concentration of the corrosion-preventing additive with respect to the cement of the mixture may be between 0.0125 wt% and 1.0 wt%.

The corrosion-preventing additive for reinforced concrete is a concrete additive for preventing corrosion of steel rebars in steel-reinforced concrete. The corrosion-preventing additive is a solution with an organic solvent, the solute being either gallic acid (3,4.5-trihydroxybenzoic acid), at least one ester of gallic acid, or combinations thereof. The weight-to-volume concentration of the solute to the organic solvent may be between 1% and 10% w/v. Reinforced concrete may be made using the corrosion-preventing additive by mixing the corrosion-preventing additive with a conventional concrete mixture (i.e., a mixture of an aggregate, water, and cement), with at least one steel rebar being embedded in the mixture, similar to conventional steel rebar reinforced concrete. The concentration of the corrosion-preventing additive with respect to the cement of the mixture may be between 0.0125 wt% and 1.0 wt%.

An interlocking system of modular units engageable to form vertically and horizontally stable assemblies. The modular units include blocks and modular panels, each having vertical and optional horizontal bores that provide passage for plumbing, electrical wiring, and other connectivity. The modular units may be formed of lightweight cementitious materials, and may find use in assemblies such as walls, floors, ceilings, roofs, and entire building structures.

An interlocking system of modular units engageable to form vertically and horizontally stable assemblies. The modular units include blocks and modular panels, each having vertical and optional horizontal bores that provide passage for plumbing, electrical wiring, and other connectivity. The modular units may be formed of lightweight cementitious materials, and may find use in assemblies such as walls, floors, ceilings, roofs, and entire building structures.

In the field of decorative floor coverings, decorative panels are known having a MDF (Medium Density Board) or HDF (High Density Board) based core layer on top of which a decorative substrate is attached to provide the panels a desired appearance. The invention relates to a panel, in particular a decorative panel, a floor panel, a ceiling panel or a wall panel. The invention also relates to a floor covering consisting of a plurality of mutually coupled panels.