An additive for a cement slurry for a well that is capable of suppressing the generation of free water and preventing flotation/separation of low-specific-gravity aggregate while securing sufficient cement strength even at a high temperature and a method for producing this additive are disclosed. The additive contains an aqueous dispersion of silica and a layered silicate.

In the present disclosure, a cement board is disclosed. The cement board comprises a core having a first surface and a second surface opposite the first surface and a binder including a pozzolan material and a water-resistant additive, wherein the water-resistant additive is present in an amount of less than 5 wt. % based on the weight of the pozzolan material.

A cementitious panel system reinforced on its opposed surfaces by a fabric of basalt fiber woven or non-woven mesh. Preferably the mesh is a woven basalt scrim with thicker yarn and larger mesh openings to provide a cementitious panel with improved handling properties while retaining tensile strength and long term durability. The fabric is constructed as a mesh of high modulus strands of bundled basalt fibers. The fabric also has suitable physical characteristics for embedment within the cement matrix of the panels or panels closely adjacent the opposed faces thereof. The fabric provides a panel system with long-lasting, high strength tensile reinforcement and improved handling properties regardless of their spatial orientation during handling. Included as part of the invention are methods for making the reinforced cementitious panel.

A process for producing foamed concrete includes introducing air pores into aqueous concrete compositions by one or more air pore formers and/or by introducing air. The aqueous concrete compositions are based on one or more foam stabilizers, one or more protective colloid-stabilized polymers of ethylenically unsaturated monomers in the form of aqueous dispersions or water-redispersible powders, 30% to 95% by weight of cement, based on the dry weight of the components for production of the concrete compositions, optionally one or more fillers, and optionally one or more additives.

In the present disclosure, a cement board is disclosed. The cement board comprises a core having a first surface and a second surface opposite the first surface and a binder including a pozzolan material and a water-resistant additive, wherein the water-resistant additive is present in an amount of less than 5 wt. % based on the weight of the pozzolan material.

A method for producing a composite insulating mineral construction element includes filling the cavity of a construction element including at least one cavity delimited by at least one inner wall at least partially having a water absorption rate of more than 5 g/(m.sup.2.Math.s) at 10 minutes according to standard NF EN 772-11 of August 2011 with a foamed cement slurry including a cement being an hydraulic binder including a proportion of at least 50% by weight of calcium oxide CaO and silicone dioxide SiO.sub.2, a metal salt selected from an aluminium, magnesium or iron salt and mixtures thereof, and a cellulose ether; and leaving the foamed cement slurry to set within the cavity resulting in the formation of a mineral foam, wherein the foamed cement slurry includes from 0.01 to 0.2% by weight of cellulose ether, relative to the weight of cement.

A method for the refurbishment of porous construction materials and a composition including Portland cement, calcined clay, and optionally aggregate to be used in the method for the refurbishment of porous construction materials. The method includes the steps of mixing water and a composition C, the composition C including, a) 100 mass parts of Portland Cement, b) 1-18 mass parts, preferably 1-10 mass parts, more preferably 1-7.5 mass parts, still more preferably 1-6 mass parts, especially 1-5 mass parts of calcined clay, c) optionally 10-250 mass parts of aggregates, applying the mixture thus obtained to a porous construction material, and optionally hardening the applied mixture.

The use of a desiccant for influencing the density of a curable binder composition including a) at least one organic binder including a polyisocyanate and a polyol, and b) at least 50% by weight of an inorganic filler F, more particularly in the form of quartz aggregates and/or slag, the proportions by weight being based on 100% by weight of the binder composition.

The present disclosure provides designs and methods for manufacturing precast fully-encapsulated bilayered fiberglass Styro-aircrete building blocks. The disclosure comprises forming a super-light air-entrained Styro-aircrete building panel for a wall, roof, or beam. The Styro-aircrete is made with a novel composition/formula using shredded Styrofoam and other traditional Styro-aircrete ingredients that are mixed. Wire meshes and fiberglass fibers are pre-embedded in the panel frame to keep the structure in place. The Styro-aircrete is poured into a fiberglass panel frame from an opening, set aside to dry for a few days, and then sealed with a fiberglass cover. This frame and cover are double-layered fiberglass and form an all six-side enclosed casing. The method and designs improve a Styro-aircrete building block with the following: (1) much lighter weight; (2) longed durability; (3) increased compressive strength for load-bearing support; (4) reduced cost and installation time.

An aerospace mirror having a reaction bonded (RB) silicon carbide (SiC) mirror substrate, and a SiC cladding on the RB SiC mirror substrate forming an optical surface on a front side of the aerospace mirror. A method for manufacturing an aerospace mirror comprising obtaining a green mirror preform comprising porous carbon, silicon carbide (SiC), or both, the green mirror preform defining a front side of the aerospace mirror and a back side of the aerospace mirror opposite the front side; removing material from the green mirror preform to form support ribs on the back side; infiltrating the green mirror preform with silicon to create a reaction bonded (RB) SiC mirror substrate from the green mirror preform; forming a mounting interface surface on the back side of the aerospace mirror from the RB SiC mirror substrate, and forming a reflector surface of the RB SiC mirror substrate on the front side of the aerospace mirror. Additionally, the method can comprise cladding the reflector surface of the RB SiC mirror substrate with SiC to form an optical surface of the aerospace mirror.