A hydraulic binder includes a Portland clinker having a Blaine specific surface of 4000 to 5500 cm.sup.2/g, from 2.5 to 8% of sulphate expressed by mass of SO.sub.3 relative to the mass of clinker, from 1.5 to 10% of calcium nitrite and/or calcium nitrate expressed as anhydrous mass relative to the mass of clinker and from 15 to 50% of a mineral addition including calcium carbonate by mass relative to the total mass of binder.

A method for treating aggregate to be used in cement is designed to perform surface treatment on aggregate by bringing fine bubble water containing fine bubbles into contact with the aggregate. The treated aggregate is used as a material for ready-mixed concrete to prepare concrete. The fine bubble water is produced by a high-speed swirling method, a pressure releasing method, or a combination thereof. The dispersibility of the aggregate is improved by the surface treatment.

The present invention relates to a composition for manufacturing methylene malonate cementitious hybrid systems. Particularly, the invention relates to a composition comprising at least one methylene malonate monomer (A), at least one methylene malonate polymer (B), at least one acidic stabilizer (C), and cement (D), to the preparation thereof, and to the use of the composition in construction, particularly as a surface protection material, a structural consolidation material or as a material used in underground constructions.

Described are compositions and methods for controlled strength development in a hydratable cementitious material, and more particularly to the use of polymerizable monomer components, which are initiated and activated by a redox pair which are mixed in controlled fashion, for enhancing non-hydration strength within the matrix of the plastic hydratable cementitious material before setting of the cementitious material begins. Exemplary applications include minimizing pressures on formwork for high fluid ready-mix applications, enhancing support and bonding properties for integrated concrete slab work and other sequential applications, or facilitating speedy 3D printing applications, among other unique possibilities.

Concrete that exhibits increased flexibility (i.e., low modulus of elasticity) and high compressive strength is described. High aspect ratio structures as may be formed of the concrete are described. Structures formed of the concrete can have the same high compressive strength as similar structures formed from a more conventional concrete but can be significantly more flexible, which can allow for better load distribution in the structure and associated assembly. The concrete includes a weathered granite as coarse aggregate. The materials can be particularly beneficial in forming concrete components of a rail infrastructure, such as railroad ties and slabs.

The present invention belongs to the field of composite materials, particularly to an underwater non-dispersible quick-setting and rapid-hardening cement-based composite material and the preparation method and application thereof. The material consists of the following raw materials in percentage by weight: 32%-34% of silicate cement, 8.8%-9% of calcium aluminate, 5%-7% of magnesium oxide, 0.5%-2% of sulfur trioxide, 0.2%-0.3% of polycarboxylate high performance water-reducing agent, 0.3%-0.7% of flocculant, 0.05%-0.2% of setting accelerator, 0.05%-0.2% of air-entraining agent, 0.05%-0.3% of rust inhibitor, 26%-31% of fine aggregate, 13%-18% of coarse aggregate, and 8.4%-8.5% of water. The material can be used for rapid repair of cement buildings in water conservancy projects, the repair material can be quickly set and the initial strength can be guaranteed.

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.

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).

This rapid-hardening cement composition includes: a rapid-hardening admixture; and cement in an amount of 100 parts by mass to 2,000 parts by mass with respect to 100 parts by mass of the rapid-hardening admixture, wherein the rapid-hardening admixture is a composition that contains: calcium aluminate; inorganic sulfate in an amount of 50 parts by mass to 200 parts by mass with respect to 100 parts by mass of the calcium aluminate; and a setting modifier in an amount of 0.1 parts by mass to 10 parts by mass with respect to 100 parts by mass of the calcium aluminate, and an average particle diameter of the calcium aluminate is in a range of 8 m to 100 m, and an average particle diameter of the setting modifier is in a range of 5 m or less.

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.