A fire-resistant gypsum panel comprises: a gypsum core layer comprising set gypsum and a high temperature sag-resistant material including mineral wool in an amount between 0.2% and 3.0% by weight of gypsum.

Disclosed are an organic binder-based coating; a composite gypsum board containing face and back cover sheets, an outside surface of the back cover sheet bearing the coating; and a method of preparing composite board where the back cover sheet contains the coating on its outer surface. The coating is formed from a composition comprising an alkaline silicate, a solid filler, and optionally, a borate. An enhancing layer can also be applied to the back cover sheet.

The present invention relates to curable compositions which comprise (meth)acrylic monomers, ethylenically unsaturated oligomers and a specific multistage polymer additive. The additive is used as a processing aid to reduce cure shrinkage and reduce or prevent the formation of cracks during the polymerization of the composition.

Disclosed are: damage-resistant ECMCs that need to work and remain elastic between minus 120° C. and positive 300° C.; ECMCs that need to be able to contain a flame of 1900° C. for more than 90 minutes; and composite structures, especially highly stressed structures. One of the characteristic problems of ceramic matrices is their fragility. Indeed, when a fracture starts, it propagates easily in the matrix. Disclosed are elastic ceramic matrix composites (ECMCs), for which: the ceramic matrix is split into solid “ceramic microdomains” (CMDs); the CMDs are connected to one another by a dense network of “elastic microelements” (EMEs); and the bonds between the EMEs and the CMDs are strong chemical bonds, preferably covalent.

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.

Disclosed are: damage-resistant ECMCs that need to work and remain elastic between minus 120° C. and positive 300° C.; ECMCs that need to be able to contain a flame of 1900° C. for more than 90 minutes; and composite structures, especially highly stressed structures. One of the characteristic problems of ceramic matrices is their fragility. Indeed, when a fracture starts, it propagates easily in the matrix. Disclosed are elastic ceramic matrix composites (ECMCs), for which: the ceramic matrix is split into solid “ceramic microdomains” (CMDs); the CMDs are connected to one another by a dense network of “elastic microelements” (EMEs); and the bonds between the EMEs and the CMDs are strong chemical bonds, preferably covalent.

Provided herein are cementitious materials, for example, a crack-resistant cementitious mortar. The cementitious materials are a mixture of cement, at least one recycled fiber reinforcement material, a recycled aggregate material, and water. Also provided is a method for increasing the crack-resistance of a cementitious material by replacing the sand in a cement mortar with a recycled aggregate material and adding at least one recycled fiber reinforcement material and a volume of water.

A method for controlling the volume expansion of a hydraulically setting composition including steel making slag, the method including a step of adding a silica source to the composition. Furthermore, hydraulically setting compositions obtained by such methods and their uses.

The present invention provides a composition for forming a lightweight, low shrinkage and hydrophobic cementitious matrix, and a method for preparing thereof. The present cementitious matrix formed by the composition is lightweight, hydrophobic (or water repelling) and with low shrinkage which is useful in building and construction industry as non-structural wall resistant to water, heat and sound entry. The present invention also provides a method of preparing the composition and the cementitious matrix formed from the composition.

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.