The present disclosure relates to a method of cementing comprising: providing a cement composition comprising: water, a cement, and a non-aqueous liquid anti-shrinkage cement additive comprising calcined magnesium oxide and a non-aqueous liquid; introducing the cement composition into a subterranean formation; and allowing the cement composition to set in the subterranean formation. Non-aqueous liquid anti-shrinkage cement additives, cement compositions, and systems are also provided.

The present invention provides a liquid composition of quicklime particles within an alkylene glycol-based paste or slurry environment, which allows for pumpability and meterability of a liquid composition into cementitious materials such as concrete and mortar. Treated quicklime particles of the present invention manifest an unexpected and surprising hydration induction postponement behavior, as demonstrated through calorimetric testing.

Mineral binder based construction materials are disclosed, including thermally pre-treated silicate glass fibers and colloidal silica and further additives, which have increased fire resistance such that they have a delayed shrinkage when exposed to high temperatures relative to a mineral binder based construction material with conventional glass fibers and colloidal silica, but otherwise of identical composition. The claimed mineral binder based construction materials provide an improved resistance towards rupture, thus ensuring that corresponding structures maintain their integrity for longer periods of time when exposed to fire. Also disclosed are methods for the production of mineral binder based construction materials and the use of thermally pre-treated silicate glass fibers and colloidal silica to effect a delay in shrinkage of mineral binder based construction materials, when exposed to elevated temperatures.

Coated inorganic expanding agent particles comprise a core of an inorganic expanding agent and a sol/gel-formed coating comprising a mixed oxide of two or more metals and/or metalloids, in particular a mixed oxide of silicon and at least one metal and/or metalloid selected from aluminum, boron, titanium, zirconium and zinc. The coated inorganic expanding agent particles are added to cementitious systems to avoid shrinkage during hardening. The coating is effective to delay the expanding effect.

A composition of a cement additive material to improve durability of cementitious structures, was disclosed. The cement additive composition includes an admixture of one or more of divalent magnesium metal silicates with capacity to act as a latent hydraulic binder in said composition activated by a hydration process under aqueous conditions, and in particular the divalent metal silicate is magnesium-dominated silicate, preferably comprising mineral groups of olivines, orthopyroxenes, amphiboles, talc and serpentines or mixtures thereof. The composition also includes chloride ions or brine. Applications of the compositions are also disclosed, in particular to utilize a property of hydration as a major trigger for the latent hydraulic reaction of magnesium silicates, particularly for said olivines, when exposed to water and brines, in order to obtain a cementitious material becoming self healing.

Described herein is a method for preparing decorative concrete top ping which overcomes the limitations associated with epoxy Terrazzo floors. Specifically, the decorative concrete topping mixture described herein has a low crack potential, high strength and durability, much longer working time, thereby allowing for the material to be mixed in larger quantities and simplifying application. A binder composition made of Portland cement and pozzolanic materials is mixed with an decorative aggregate and other additives before pumping the concrete topping mixture onto a subfloor and allowing the concrete topping mixture to cure.

The present disclosure relates to a method of cementing comprising: providing a cement composition comprising: water, a cement, and a non-aqueous liquid anti-shrinkage cement additive comprising calcined magnesium oxide and a non-aqueous liquid; introducing the cement composition into a subterranean formation; and allowing the cement composition to set in the subterranean formation. Non-aqueous liquid anti-shrinkage cement additives, cement compositions, and systems are also provided.

The present invention is to provide an economical and efficient method of reducing drying shrinkage of a cement-based hardened body without requiring the cost and/or the labor and time. A cement-based hardened body is impregnated with a solution containing urea or a solution containing sulfate together with urea. An impregnation treatment may be by a method of coating or spraying the cement-based hardened body with the solution, or alternatively, immersing the cement-based hardened body in the solution containing both urea and sulfate for a predetermined period of time. The solution containing both urea and sulfate may be a solution prepared simply by dissolving both urea and sulfate in water. Besides, there are no particular limitations on a liquid allowing dissolution of both urea and sulfate, so long as it causes no impairment of a drying shrinkage reduction effect, and therefore, a solution having the drying shrinkage reduction effect in itself is also applicable for use of a solution containing both urea and sulfate in a state of being dissolved in such solution.

A preparation method of comb structure temperature/pH-responsive polycarboxylic acid adopts acrylic ester, temperature/pH-responsive monomer and other raw materials to obtain polycarboxylic acid via acrylate monomer self-polymerization, grafting with temperature/pH-responsive monomers and hydrolyzation. In other words, acrylate is used as the reaction monomer to polymerize polyacrylate with controllable molecular weight under the action of initiator and chain transfer agent, then the graft copolymers are copolymerized with temperature/pH-responsive monomers to obtain graft copolymers with acrylate polymers main chain and temperature/pH-responsive polymer side chains. Finally, the graft copolymer is hydrolyzed to obtain the comb structure temperature/pH-responsive polycarboxylic acid with polyacrylic acid main chain and temperature/pH-responsive monomer side chain.

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.