Concrete compositions containing cement, a fine aggregate such as sand, a coarse aggregate such as crushed limestone, an industrial waste material such as electric arc furnace dust, cement kiln dust, oil ash, or limestone powder. High performance concretes made therefrom and methods of producing such concretes are also specified. The addition of industrial waste materials and nano silica provides enhanced mechanical strength (e.g. compressive strength, flexural strength) and improved durability (e.g. resistance to penetration of chloride ions) to the high performance concretes.

The present invention relates to improved concrete elements, particularly to self-prestressed, high-performance concrete elements (SP-HPC elements); to cementitious compositions suitable, for producing such concrete elements; to methods of manufacturing such concrete elements and such cementitious compositions; to the use of specific components in concrete elements and cementitious mixtures. The compositions and elements described herein comprise an effective amount of expansive agents in combination with superabsorbent polymers (SAP) and shrinkage reducing admixtures (SRA), and optional further components as defined in the claims. The present invention further provides for improved tendons, suitable for SP-HPC elements.

A formulation and method for obtaining ultra-high performance concretes, which provide a concrete with good mechanical properties of, inter alia, traction, compression, deformation, durability, ductility and toughness, with reduced related costs.

A macro-cement and associated methods useful for preparing pastes, mortars, concretes and other cement-based materials having high workability, high density, and high strength are disclosed. A method of producing a macro-cement includes cement, supplemental cementitious materials (SCM's), including siliceous submicron-sized particles and nano-sized particles, and polymers in the form of liquid or dry chemical admixtures for concrete. The cement mixture may be used for making ultra-high performance concrete (UHPC).

Provided is a cement composition that has high fluidity (for example, a 0-drop flow value of 200 mm or more) before curing and exhibits high compressive strength (for example, 320 N/mm.sup.2 or more) after curing. The cement composition includes a cement, a silica fume having a BET specific surface area of from 10 m.sup.2/g to 25 m.sup.2/g, an inorganic powder having a 50% cumulative particle size of from 0.8 m to 5 m, a fine aggregate having a maximum particle size of 1.2 mm or less, a water reducing agent, an antifoaming agent, and water. The ratio of the cement is from 55 vol % to 65 vol %, the ratio of the silica fume is from 5 vol % to 25 vol %, and the ratio of the inorganic powder is from 15 vol % to 35 vol % in the total amount of 100 vol % of the cement, the silica fume, and the inorganic powder.

A method for the preparation of industrial-scale concrete installations with improved compression strength, curling, cracking and cracking characteristics, the method comprising the addition of nanosilica particulate, and more preferably, colloidal amorphous silica, having specific size and surface area characteristics to a concrete mix after water has been added to the mix and the mix has been agitated.

An embodiment includes a Class C fly ash (CFA) cementitious composition with a controllable setting time comprising at least one Class C fly ash; at least one alkali hydroxide; at least one source of phosphate; and water. Alternate embodiments include a Class C fly ash (CFA) cementitious composition with a solid activator comprising at least one Class C fly ash; at least one alkali carbonate; at least one source of phosphate; and water.

Cement slurries, cured cements, and methods of making cured cement and methods of using cement slurries are provided. The cement slurries have, among other attributes, improved elasticity and self-healing properties and may be used, for instance, in the oil and gas drilling industry. The cement slurry comprises water, a cement precursor material, and a block copolymer composition. The block copolymer composition has at least one copolymer backbone, with each copolymer backbone comprising at least two hard segments. Furthermore, a soft segment is disposed between the at least two hard segments. The copolymer backbone has at least one anhydride group grafted onto the soft segment, and the anhydride group is crosslinked by an aminosilane crosslinker.

A cementitious composition includes (i) white Portland cement having a fineness of about 350-550 m.sup.2/kg, D90 between about 11-50 m, and total combined iron oxide, manganese oxide, and chromium oxide <1.0% by weight (ii) light color pozzolan such as white silica fume, and (iii) at least one light color particulate material, such as ground granulated blast furnace slag (GGBFS) having a fineness greater than that of the white Portland cement, a D90 less than that of the white Portland cement, and total combined iron oxide, manganese oxide, and chromium oxide content <3.0% by weight and/or coarse limestone powder having a D90 greater than that of the white cement. The cementitious composition may include one or more of aggregates, fibers, or admixture. The cementitious composition can be a dry blend, fresh cementitious mixture, or hardened cementitious composition. The cementitious composition can be precast concrete, stucco, GFRC, UHPC or SCC.

The present invention relates to a material system for 3D printing, to a 3D printing process using a lignin-containing component or derivatives thereof or modified lignins, to soluble moldings that are produced by a powder-based additive layer manufacturing process and to the use of the moldings.