The present invention provides an admixture composition comprising a liquid suspension of colloidal silica, siloxane, and polycarboxylate polymer cement dispersant for enhancing early age strength, finishability, and other properties in hydratable cementitious compositions such as concrete (e.g., shotcrete). An inventive method involves mixing the components together in a specific sequence, thereby to obtain a stable liquid suspension. This attainment of a stable liquid suspension is surprising and unexpected because (i) the polycarboxylate polymer cement dispersant and siloxane components are incompatible and immiscible with one another; and (ii) that colloidal silica and siloxane compound are incompatible and immiscible with one another. Yet, the present inventors achieved an additive in the form of a stable liquid suspension which can be conveniently dosed into concretes and shotcrete mixtures, to enhance early age strength, and to improve workability and rheology in terms of finishability of concrete surfaces and improved rebound performance in shotcrete applications.

The present invention corresponds to a cement formulation based on sulfoaluminate comprising a specific Ye'elimite crystal proportion having enhanced mechanical resistance, setting and low CO2 emission features. A concrete obtained when mixing said formulation with water and gypsum is further described, having a superior performance at initial ages compared to concrete obtained from Portland cement.

[Problem] To provide aggregate for ready-mixed concrete that achieves an improvement in dispersibility.

[Solution] An aggregate surface treatment method of the present invention is designed to perform surface treatment on aggregate for ready-mixed concrete by bringing fine bubble water containing fine bubbles into contact with the aggregate. By doing so, the aggregate surface treatment method of this invention is able to improve the dispersibility of the aggregate.

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.

The present invention provides an admixture composition comprising a liquid suspension of colloidal silica, siloxane, and polycarboxylate polymer cement dispersant for enhancing early age strength, finishability, and other properties in hydratable cementitious compositions such as concrete (e.g., shotcrete). An inventive method involves mixing the components together in a specific sequence, thereby to obtain a stable liquid suspension. This attainment of a stable liquid suspension is surprising and unexpected because (i) the polycarboxylate polymer cement dispersant and siloxane components are incompatible and immiscible with one another; and (ii) that colloidal silica and siloxane compound are incompatible and immiscible with one another. Yet, the present inventors achieved an additive in the form of a stable liquid suspension which can be conveniently dosed into concretes and shotcrete mixtures, to enhance early age strength, and to improve workability and rheology in terms of finishability of concrete surfaces and improved rebound performance in shotcrete applications.

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.

The present invention corresponds to a cement formulation based on sulfoaluminate comprising a specific Ye'elimite crystal proportion having enhanced mechanical resistance, setting and low CO2 emission features. A concrete obtained when mixing said formulation with water and gypsum is further described, having a superior performance at initial ages compared to concrete obtained from Portland cement.

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 course aggregate. The materials can be particularly beneficial in forming concrete components of a rail infrastructure, such as railroad ties and slabs.

The present invention aims to provide a composition with higher ability to enhance early strength development compared to conventional compositions. The present invention relates to an aluminosilicate-containing composition containing: an aluminosilicate; and a water-soluble polymer, the aluminosilicate-containing composition further containing at least one of an amine having a molecular weight of not more than 1,000 or a metal compound.