A nano-modified material for cavity wall with insulation for prefabricated building, preparation method and application thereof, belonging to the technical field of building materials. The material includes splicing structures and a nano-modified silane waterproof coating, wherein the splicing structure includes a recycled concrete structure layer and a nano-modified foam concrete thermal insulation core layer, the recycled concrete structure layer is a hollow cuboid structure with openings at both ends, the nano-modified foam concrete thermal insulation core layer is a structure formed by casting inside the recycled concrete structure layer, and the nano-modified silane waterproof coating is applied at a butt joint of two of the splicing structures.

The present disclosure provides a recycled powder concrete material for 3D printing construction and a preparation method therefor. The concrete material includes the following components by weight parts: cement: 1.0 part; recycled powder: 0.1-2.0 parts; recycled fine aggregate: 1.0-12.0 parts; nano titanium dioxide: 0.001-0.18 parts; high elastic modulus polyethylene fiber: 0.005-0.15 parts; redispersible latex powder: 0.002-0.1 parts; cellulose: 0.001-0.045 parts; activator: 0.01-0.30 parts; polycarboxylic acid water reducing agent: 0.005-0.2 parts; and water: 0.2-2.0 parts. According to the recycled powder concrete material for 3D printing construction, construction waste recycling powder technology is combined with 3D printing construction technology. The safety, applicability and durability of 3D printing recycled powder concrete material are further improved through the optimization of the recycled powder concrete formula. At the same time, the 3D printing recycled powder concrete material has self-cleaning functionality.

The present disclosure provides a recycled powder concrete material for 3D printing construction and a preparation method therefor. The concrete material includes the following components by weight parts: cement: 1.0 part; recycled powder: 0.1-2.0 parts; recycled fine aggregate: 1.0-12.0 parts; nano titanium dioxide: 0.001-0.18 parts; high elastic modulus polyethylene fiber: 0.005-0.15 parts; redispersible latex powder: 0.002-0.1 parts; cellulose: 0.001-0.045 parts; activator: 0.01-0.30 parts; polycarboxylic acid water reducing agent: 0.005-0.2 parts; and water: 0.2-2.0 parts. According to the recycled powder concrete material for 3D printing construction, construction waste recycling powder technology is combined with 3D printing construction technology. The safety, applicability and durability of 3D printing recycled powder concrete material are further improved through the optimization of the recycled powder concrete formula. At the same time, the 3D printing recycled powder concrete material has self-cleaning functionality.

A device and method for reinforcing recycled aggregate based on in-situ C—S—H production including a first, second, third chamber, and a blast drier. A spray structure arranged on the top of the third chamber; the first and second chamber connected to the spray structure through pumps. A hollowed container arranged at the bottom of the spray structure. A certain gap reserved between the bottom of the container and the bottom of the third chamber, the bottom of the third chamber is provided with at least one drain outlet; the blast drier connected to the bottom of the third chamber, and a cover is arranged on the top of the third chamber. The first chamber contains calcium hydroxide solution. The second chamber contains a mixed solution of TEOS, water and anhydrous ethanol. The container is arranged in the third chamber, and the container is used to contain to-be-treated recycled aggregate.

A device and method for reinforcing recycled aggregate based on in-situ C—S—H production including a first, second, third chamber, and a blast drier. A spray structure arranged on the top of the third chamber; the first and second chamber connected to the spray structure through pumps. A hollowed container arranged at the bottom of the spray structure. A certain gap reserved between the bottom of the container and the bottom of the third chamber, the bottom of the third chamber is provided with at least one drain outlet; the blast drier connected to the bottom of the third chamber, and a cover is arranged on the top of the third chamber. The first chamber contains calcium hydroxide solution. The second chamber contains a mixed solution of TEOS, water and anhydrous ethanol. The container is arranged in the third chamber, and the container is used to contain to-be-treated recycled aggregate.

A device and method for reinforcing recycled aggregate based on in-situ C—S—H production including a first, second, third chamber, and a blast drier. A spray structure arranged on the top of the third chamber; the first and second chamber connected to the spray structure through pumps. A hollowed container arranged at the bottom of the spray structure. A certain gap reserved between the bottom of the container and the bottom of the third chamber, the bottom of the third chamber is provided with at least one drain outlet; the blast drier connected to the bottom of the third chamber, and a cover is arranged on the top of the third chamber. The first chamber contains calcium hydroxide solution. The second chamber contains a mixed solution of TEOS, water and anhydrous ethanol. The container is arranged in the third chamber, and the container is used to contain to-be-treated recycled aggregate.

A low strength backfill material having a 28 days compressive strength less than approximately 2.0 MPa is provided. The backfill is suitable for use in areas with dense underground utilities due to its high excavatability and good thermal conductivity. The backfill includes a cementitious binder of approximately 1 weight percent to approximately 10 weight percent and fine aggregates in an amount of approximately 40 to approximately 75 weight percent. Filler is provided at 20 microns to approximately 100 microns for high flowability. A density-controlling agent of 0.0001-5 weight percent is used such that the density of a cured backfill material is approximately 1600 kg/m.sup.3 to 2000 kg/m.sup.3. Thermally conductive particles having a size range of approximately 0.01 microns to 500 microns in an amount of approximately 0.1 to 10 weight percent are evenly dispersed throughout the backfill.

A low strength backfill material having a 28 days compressive strength less than approximately 2.0 MPa is provided. The backfill is suitable for use in areas with dense underground utilities due to its high excavatability and good thermal conductivity. The backfill includes a cementitious binder of approximately 1 weight percent to approximately 10 weight percent and fine aggregates in an amount of approximately 40 to approximately 75 weight percent. Filler is provided at 20 microns to approximately 100 microns for high flowability. A density-controlling agent of 0.0001-5 weight percent is used such that the density of a cured backfill material is approximately 1600 kg/m.sup.3 to 2000 kg/m.sup.3. Thermally conductive particles having a size range of approximately 0.01 microns to 500 microns in an amount of approximately 0.1 to 10 weight percent are evenly dispersed throughout the backfill.

The present invention relates to a gypsum composition comprising recycled gypsum and a foam former comprising at least one alpha-sulfo fatty acid disalt, to a process for production thereof and to an article comprising the gypsum composition of the invention. The present invention further relates to the use of a foam former comprising at least one alpha-sulfo fatty acid disalt for reducing the wet density of an aqueous gypsum composition having a recycled gypsum content of at least 0.5% by weight.

A method of making a structural lightweight and thermal insulating concrete is described. The concrete has a coarse aggregate partly replaced by recycled plastic pieces. This enables the concrete to maintain a high compressive strength, low thermal conductivity, and low weight, while providing a use for waste plastic. The waste plastic pieces may comprise polyethylene in the form of flakes, fibers, or granules. Due to its low unit weight, adequate compressive strength and high thermal resistance the developed concrete can be used as a structural lightweight and thermal insulating concrete. The use of this concrete leads to economic and environmental benefits.