An aqueous oil-in-water emulsion containing a propylethoxysilane oligomer mixture or a mixture of a propylethoxysilane oligomer mixture and octyltriethoxysilane in a weight ratio of 3:1 to 1:3, at least one emulsifier or an emulsifier system, at least one content of a 2-aminoethanol and water is used as an addition in the production of hydraulically setting cement mixtures such as mortar, screed or concrete for reduction of the shrinkage characteristics.

The present invention provides a calcium sulphate-based product (e.g. a wall board) comprising gypsum, a pozzolan source such as a clay additive, rice husk ash or diatomaceous earth and a metal salt additive. The product may be produced by drying an aqueous slurry comprising calcined gypsum, the pozzolan source and the metal salt additive. The clay additive may be a kaolinitic clay. The metal salt additive may be a magnesium salt e.g. magnesium nitrate, magnesium chloride or magnesium hydroxide.

A coating process comprising applying to a surface a coating composition consisting essentially of an alkali metal silicate and an aqueous liquid phase having dispersed therein solid aluminum particles to form on the surface a wet coating; and drying said wet coating: under conditions which convert said wet coating to an electrically conductive, corrosion-resistant, solid coating; or under conditions which form a solid coating which is not electrically conductive (non-conductive) and thereafter treating said non-conductive coating under conditions which convert said non-conductive coating to an electrically conductive, corrosion-resistant coating.

The present invention aims to provide a shrinkage reducing agent that exhibits high performance to reduce the shrinkage of hydraulic materials. The present invention relates to a shrinkage reducing agent for a hydraulic material including a compound that satisfies the following conditions (1) to (4): (1) a ratio represented by {(15-drop flow value of a mortar composition containing the compound)/(15-drop flow value of a mortar free from the compound)}×100 is 120 or less, wherein the (15-drop flow value of a mortar composition containing the compound) means a 15-drop flow value of a mortar composition containing the compound at a solid concentration of 0.1% after 10 minutes mixing and the (15-drop flow value of a mortar free from the compound) means a 15-drop flow value of a mortar free from the compound after 10 minutes mixing; (2) a ratio represented by {(ratio between 15-drop flow values after two hours mixing)/(ratio between 15-drop flow values after 10 minutes mixing)}×100 is 110 or less, wherein the (ratio between 15-drop flow values after two hours mixing) means a ratio of a 15-drop flow value of a mortar composition containing the compound at a solid concentration of 0.1% after two hours mixing to a 15-drop flow value of a mortar free from the compound after two hours mixing, and the (ratio between 15-drop flow values after 10 minutes mixing) means a ratio of a 15-drop flow value of a mortar composition containing the compound at a solid concentration of 0.1% after 10 minutes mixing to a 15-drop flow value of a mortar free from the compound after 10 minutes mixing; (3) the compound has an average particle diameter of 2.2 to 8.5 nm in an alkaline solution; and (4) a product of {(ratio between 15-drop flow values relating to a mortar composition containing the compound at a solid concentration of 1.0%)×(ratio between 15-drop flow values relating to a mortar composition containing the compound at a solid concentration of 0.1%)} is 10,100 or more, wherein the (ratio between 15-drop flow values relating to a mortar composition containing the compound at a solid concentration of 1.0%) means a ratio of a 15-drop flow value of a mortar composition containing the compound at a solid concentration of 1.0% after 10 minutes mixing to a 15-drop flow value of a mortar free from the compound after 10 minutes mixing, and the (ratio between 15-drop flow values relating to a mortar composition containing the compound at a solid concentration of 0.1%) means a ratio of a 15-drop flow value of a mortar composition containing the compound at a solid concentration of 0.1% after 10 minutes mixing to a 15-drop flow value of a mortar free from the compound after 10 minute

A cementitious mixture for a 3D printer, with improved performance, is described, and its relative use, more specifically for the production of finished products having a complex geometry using a 3D printing apparatus.

Expansive cement compositions for use in subterranean wellbores that include a monophase amorphous hydraulic binder material (MAHBM). The MAHBM may include a plurality of particles having a silica core and an amorphous coating substantially surrounding the silica core. The coating may comprise, for example, a plurality of amorphous α-dicalcium silicate hydrate nanoparticles or microparticles. The MAHBM may be used as an expansion agent in a cement composition or used as an expansive cement by itself.

The present invention provides calcium sulphate-based product having reduced shrinkage after exposure to high temperatures, the product comprising gypsum, a pozzolan source e.g. in an amount between 4-27 wt %) and a metal salt additive in an amount between 0.5 and 10 wt %). The pozzolan source may be selected from a kaolinitic clay material, fly ash, rice husk ash, diatomaceous earths, volcanic ashes and pumices, micro-silica, silica fume and silicone oil, The metal salt additive may be a metal salt which decomposes between a temperature of 300-500° C. to yield a metal oxide, e.g. magnesium nitrate.

Disclosed are a mixed shrinkage reducing agent for concrete and a preparation method thereof. The mixed shrinkage reducing agent for concrete includes the following components in parts by weight: 35-45 of alkali modified diatomite, 15-22 of magnesium oxide, 13-20 of vermiculite, 8-11 of borax, 3-9 of sodium hexametaphosphate, and 7-13 of citric acid modified starch. The mixed shrinkage reducing agent for concrete according to the present application is used as an admixture to be mixed into cement for preparing concrete.

The present disclosure provides asphalt modified red mud for porous pavement material and an application thereof. The porous asphalt pavement material includes asphalt, red mud and aggregate; the mass ratio of asphalt to red mud is 1:(0.10-0.15), the mass ratio of the total mass of asphalt and red mud to aggregate is (0.08-0.12):1. With regard to the asphalt modified with red mud for porous pavement material provided in the present disclosure, asphalt is modified with red mud, and aggregate is added to synergize with red mud so as to improve the purification properties and mechanical properties of the porous asphalt pavement material efficiently. In the embodiments of the present disclosure, the purification rate of suspended matter by the asphalt modified with red mud for porous pavement material reaches 54.9-58.6%, and the purification rate of heavy metals (iron and lead) reaches 34.3-46.1%.

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.