An accelerator powder for cement and also rapid-setting binder compositions which contain the accelerator powder and the use in mortar or concrete. The accelerator powder includes from 10 to 99.7% by weight of a water-insoluble mineral powder P and from 0.3 to 90% by weight of at least one compound V selected from the group consisting of alkali metal halides and alkaline earth metal halides, alkali metal nitrates and alkaline earth metal nitrates, alkali metal nitrites and alkaline earth metal nitrites, alkali metal thiocyanates and alkaline earth metal thiocyanates and hydroxyalkylamines or salts thereof, and mixtures thereof.

The present disclosure provides a concrete structure strengthened using a grid reinforcement material and non-shrink grout and a method of strengthening the same in which, when strengthening a concrete structure such as a concrete slab or a concrete wall body that is damaged or deteriorated, a grid reinforcement material is mounted on one side of the concrete structure, a formwork is formed on an outer side of the grid reinforcement material to have a required gap, and then the gap is filled with non-shrink grout so that the non-shrink grout is cured therein to strengthen the old concrete structure, thereby being able to automatically fill and repair cracks formed in the concrete structure just by injecting the non-shrink grout without separately performing crack repair on the old concrete structure. Also, the grid reinforcement material may be easily fixed or mounted using a grid fixing device and may be easily applied to strengthening of a concrete structure having a curved surface as well as a concrete structure having a flat surface such as a concrete slab or a concrete wall body. In addition, reinforcing bars may be additionally arranged in a gap between a surface of the concrete structure and the grid reinforcement material so that the grid reinforcement material increases a cover thickness, and thus the concrete structure is remarkably strengthened.

An embodiment according to the present invention provides a dental gypsum powder including a hemihydrate gypsum and a water-reducing agent, wherein the mass ratio of the water-reducing agent to the hemihydrate gypsum is 0.1 to 1%, the content of particles having a particle diameter of 10 μm or less is 15 to 35 volume %, the content of particles having a particle diameter of 20 μm or less is 40 to 55 volume %, and the content of particles having a particle diameter of 30 μm or less is 55 to 75 volume %.

A method for the construction of a data center, includes (a) providing a fresh concrete composition including a paste that includes a hydraulic binder, a mineral addition and water, the paste being present in a mixture with sand and aggregates, whereby the paste is present in the concrete composition in a volume of <320 L/m.sup.3 and/or the solid volume fraction of said paste is >50 vol.-% and (b) placing the fresh concrete composition so as to build walls, a floor and/or a ceiling of the data center, which are intended to surround the individual components of computer systems, which are housed in the data center.

The invention comprises a composition comprising hyaloclastite having a volume-based mean particle size of less than or equal to 40 m. The invention also comprises a cementitious material comprising a hydraulic cement and hyaloclastite, wherein the hyaloclastite has a volume-based mean particle size of less than or equal to approximately 40 m. The invention further comprises a cementitious-based material comprising aggregate, a cementitious material comprising a hydraulic cement and hyaloclastite, wherein the hyaloclastite has a volume-based mean particle size of less than or equal to approximately 40 m and water sufficient to hydrate the cementitious material. A method of using the composition of the present invention is also disclosed.

A dispersant for premixed fluidized solidified soil includes the following raw materials in parts by weight: 5 parts to 15 parts of an anti-adhesion water reducer, 0.5 parts to 0.8 parts of a stabilizer, and 85 parts to 95 parts of water. The anti-adhesion water reducer is compounded by an inorganic dispersant and an aminosulfonic acid-based superplasticizer (ASP), and the inorganic dispersant is at least one selected from the group consisting of sodium silicate, sodium hexametaphosphate, and sodium pyrophosphate. In the present disclosure, on the premise of improving fluidity of mucky cohesive soil slurry, a strength of the fluidized solidified soil at each stage is adjusted through a water-reducing effect of the anti-adhesion water reducer. Moreover, rapid dispersion of the mucky cohesive soil slurry is realized, thus providing key technical support for preparation of the premixed fluidized solidified soil from undisturbed soil in non-dry conditions.

An ultra-high performance concrete (UHPC) with waste brick powder and preparation method and application thereof are provided, which relates to the technical field of concrete. The preparation method includes the following steps: stimulating activity of a brick powder by a method of mechanically stimulating activity to obtain waste brick powder; and preparing UHPC according to a mass ratio of cement to waste brick powder of 5:5-7:3 to obtain the UHPC with waste brick powder. The UHPC is prepared by treating waste bricks from construction waste (mechanically stimulating activity) to make waste brick powder with activity, therefore partially replacing cement. The UHPC is applied in a construction field.

The present invention discloses a multitype-adsorptive-group polycarboxylic acid water-reducing agent, consisting of 30-60 wt % of a macromolecule with multitype-adsorptive groups and water, the macromolecule with multitype-adsorptive groups has a polyethylene glycol side chain, and adsorption groups of the polymer backbone include a carboxylic acid group, a sulfonic acid group and a phosphoric acid group, the phosphoric acid group being linked to the backbone of the macromolecule with multitype-adsorptive groups by nucleophilic addition. The water-reducing agent of the present invention has significantly improved adaptability to different cements and aggregates while maintaining a high water reduction efficiency, compared with the conventional polycarboxylic acid water-reducing agent agent. It has a good water reducing efficiency in many different grades of cement, as well as a better resistance to aggregates containing more impurities such as machine-made sand.

An interface joint material based on industrial solid waste includes raw materials in parts by weight: portland slag cement, 80?130 parts; metakaolin, 80?130 parts; the industrial solid waste, 80?130 parts; sodium silicate, 25?35 parts; alkali, 8?12 parts; acrylate, 30?36 parts; a trivinyl ether compound, 1?3 parts; inorganic sulfite, 1?3 parts; persulfate, 1?3 parts; a water reducing agent, 3?6 parts, and water, 60?80 parts. The interface joint material is suitable for a concrete interface of different components, with good bonding, high strength, and the advantages of pumping, fast hard, early strength, micro expansion and high ductility; In addition, the industrial solid waste is added into the interface joint material, which improves a utilization rate of the industrial solid waste in construction joint materials, and has significant for recycling of the industrial solid waste.

This disclosure is directed to an improved ballistic concrete barrier for stopping projectiles with a kinetic energy of between about 1.0 kJ (750 foot-pounds) and 20.3 kJ (15,000 foot-pounds) in between about 3 inches and 10 inches. In one embodiment, the ballistic concrete barrier comprises (a) about 1 part by mass Portland cement; (b) about 0.5 to 1.5 part by mass fine aggregate; (c) about 0.005 to 0.15 part by mass fiber; (d) about 0.005 to 0.05 part by mass calcium phosphate; (e) about 0.005 to 0.05 part by mass aluminum hydroxide; and (f) about 0.0005 to 0.05 part by mass air entrainment additive, such that the ballistic concrete barrier is capable of stopping a fifty caliber bullet in less than 10 inches from a point of entry into the barrier.