The present invention relates to a thermal insulating composition, containing 5 to 60% by weight of a hydrophobized granular material comprising fumed silica and at least one IR-opacifier, and 40 to 95% by weight of an inorganic and/or an organic binder, whereby the hydrophobized granular material has a content of free hydroxyl groups of no greater than 0.12 mmol/g, as determined by the reaction with lithium aluminium hydride.

Lost circulation materials may be particles having a core-shell structure. Said particles may include: a core comprising an expandable material; and a shell around the core, the shell comprising an outer permeable membrane, an inner permeable membrane, and a hardenable material between the outer and inner permeable membranes; and wherein the core-shell structure is folded. The particles may be initially folded where, upon exposure to a stimulus, the core expands in volume (which unfolds the particles) and the shell increases in strength. The expanded particles can then clog large openings/apertures in the formation.

Lost circulation materials may be particles having a core-shell structure. Said particles may include: a core comprising an expandable material; and a shell around the core, the shell comprising an outer permeable membrane, an inner permeable membrane, and a hardenable material between the outer and inner permeable membranes; and wherein the core-shell structure is folded. The particles may be initially folded where, upon exposure to a stimulus, the core expands in volume (which unfolds the particles) and the shell increases in strength. The expanded particles can then clog large openings/apertures in the formation.

A method of producing a nanosilica-containing cement formulation, the method comprising the steps of mixing an amount of a determinant nanosilica particle and a functional coating; applying a dynamic initiator to trigger a reversible reaction of the functional coating to produce a reversible cage, where the reversible cage surrounds the determinant nanosilica particle to produce an encapsulated nanosilica; and mixing the encapsulated nanosilica and a cement formulation to produce the nanosilica-containing cement formulation.

A method of producing a nanosilica-containing cement formulation, the method comprising the steps of mixing an amount of a determinant nanosilica particle and a functional coating; applying a dynamic initiator to trigger a reversible reaction of the functional coating to produce a reversible cage, where the reversible cage surrounds the determinant nanosilica particle to produce an encapsulated nanosilica; and mixing the encapsulated nanosilica and a cement formulation to produce the nanosilica-containing cement formulation.

High-strength, lightweight core-shell aggregates are formed from waste materials. The aggregates include porous core materials which may be one or more of perlite, vermiculite, cenospheres, expanded polystyrene, or biochar. Formed on the core materials is at least one layer of shell material which includes one or more of GGBS, fly ash, recycled concrete powder, recycled glass powder, or biochar powder. The high-strength, lightweight core- shell aggregates have a loose bulk density less than approximately 980 kg/m.sup.3, a crushing strength higher than approximately 4 MPa, a water absorption of less than 20%, and a carbon emission of approximately 181 kgCO.sub.2eq/t or less. Lightweight concrete is formed by incorporating the high-strength, lightweight core-shell aggregates with cement to create concrete with a density of 1900 kg/m.sup.3 or less.

High-strength, lightweight core-shell aggregates are formed from waste materials. The aggregates include porous core materials which may be one or more of perlite, vermiculite, cenospheres, expanded polystyrene, or biochar. Formed on the core materials is at least one layer of shell material which includes one or more of GGBS, fly ash, recycled concrete powder, recycled glass powder, or biochar powder. The high-strength, lightweight core- shell aggregates have a loose bulk density less than approximately 980 kg/m.sup.3, a crushing strength higher than approximately 4 MPa, a water absorption of less than 20%, and a carbon emission of approximately 181 kgCO.sub.2eq/t or less. Lightweight concrete is formed by incorporating the high-strength, lightweight core-shell aggregates with cement to create concrete with a density of 1900 kg/m.sup.3 or less.

A lightweight aggregate for use in forming lightweight cementitious mixes and/or concrete is formed by encapsulating a plurality of hydrophobic polymer particles (e.g., expanded polystyrene particles) in an encasement having a first layer of a cementitious material and a second layer of a pozzolan or mineral. The lightweight aggregate can be included as at least part of the aggregate component of a cementitious mix to form a lightweight cementitious mix. The lightweight aggregate and/or lightweight cementitious mix can be used to form lightweight concrete. The encasement of the lightweight aggregate allows the cement of the cementitious mix or concrete composition to bond to the lightweight aggregate, thereby promoting strength and durability of the concrete mixture.

A lightweight aggregate for use in forming lightweight cementitious mixes and/or concrete is formed by encapsulating a plurality of hydrophobic polymer particles (e.g., expanded polystyrene particles) in an encasement having a first layer of a cementitious material and a second layer of a pozzolan or mineral. The lightweight aggregate can be included as at least part of the aggregate component of a cementitious mix to form a lightweight cementitious mix. The lightweight aggregate and/or lightweight cementitious mix can be used to form lightweight concrete. The encasement of the lightweight aggregate allows the cement of the cementitious mix or concrete composition to bond to the lightweight aggregate, thereby promoting strength and durability of the concrete mixture.

A lightweight aggregate for use in forming lightweight cementitious mixes and/or concrete is formed by encapsulating a plurality of hydrophobic polymer particles (e.g., expanded polystyrene particles) in an encasement having a first layer of a cementitious material and a second layer of a pozzolan or mineral. The lightweight aggregate can be included as at least part of the aggregate component of a cementitious mix to form a lightweight cementitious mix. The lightweight aggregate and/or lightweight cementitious mix can be used to form lightweight concrete. The encasement of the lightweight aggregate allows the cement of the cementitious mix or concrete composition to bond to the lightweight aggregate, thereby promoting strength and durability of the concrete mixture.