The present invention primarily relates to the use of a mixture capable of biocementation as a means of preventing or reducing plant growth, preferably weed growth. The invention also relates to a method for preventing or reducing plant growth, preferably weed growth, on/in a substrate.

A nanobubble-infused liquid is mixed into a dry concrete mix to form an infused wet concrete, where the nanobubble-infused liquid includes a concentration of nanobubbles of a gas at least double a natural concentration of nanobubbles of the gas within a natural state of the liquid. The nanobubble-infused liquid is preferably liquid water infused with a desired concentration of carbon-dioxide (CO.sub.2) nanobubbles sized within a certain prescribed range. The infused wet concrete is then transported to the mold of a concrete products forming machine to form a molded product that has enhanced qualities including increased carbon capture within the resulting concrete product, improved curing times, increased flowability, self-healing, and improved release from the product mold.

Concrete made using the protocol described herein converts more of the available calcium hydroxide (Ca(OH).sub.2) into calcium carbonate (CaCO.sub.3) and distributes it more thoroughly throughout the concrete mixture by converting it into calcium bicarbonate (Ca(HCO.sub.3).sub.2) by adjusting the pH of the hydrating liquid and then deliberately adjusting the pH of the hydrating liquid again when precipitation of the CaCO.sub.3 from the hydration liquid is desired to more uniformly coat the materials used in a concrete mix. This process creates more CaCO.sub.3 in concrete than current methods on the market and that has been demonstrated to increase the structural and chemical properties of the concrete.

Concrete made using the protocol described herein converts more of the available calcium hydroxide (Ca(OH).sub.2) into calcium carbonate (CaCO.sub.3) and distributes it more thoroughly throughout the concrete mixture by converting it into calcium bicarbonate (Ca(HCO.sub.3).sub.2) by adjusting the pH of the hydrating liquid and then deliberately adjusting the pH of the hydrating liquid again when precipitation of the CaCO.sub.3 from the hydration liquid is desired to more uniformly coat the materials used in a concrete mix. This process creates more CaCO.sub.3 in concrete than current methods on the market and that has been demonstrated to increase the structural and chemical properties of the concrete.

Disclosed is a CO.sub.2 solidified fiber cement board and its preparation method. The matrix composition of the fiber cement board prepared in this disclosure is calcium carbonate, which has high compactness, and the crystal form of calcium carbonate is adjusted by adding shell powder to improve the toughness of the matrix, so that the fiber cement board has excellent mechanics and durability performance. In addition, the preparation process does not require high temperature maintenance, and has the characteristics of normal temperature preparation, which creates conditions for the introduction of organic synthetic fibers, so that the organic synthetic fibers can further improve the brittleness of cement fiberboard. While reducing energy consumption, the preparation process can also effectively solve the problem that excessive pressure is easily generated in the fiberboard under high temperature conditions in the existing high-temperature and high-pressure curing process.

Disclosed is a CO.sub.2 solidified fiber cement board and its preparation method. The matrix composition of the fiber cement board prepared in this disclosure is calcium carbonate, which has high compactness, and the crystal form of calcium carbonate is adjusted by adding shell powder to improve the toughness of the matrix, so that the fiber cement board has excellent mechanics and durability performance. In addition, the preparation process does not require high temperature maintenance, and has the characteristics of normal temperature preparation, which creates conditions for the introduction of organic synthetic fibers, so that the organic synthetic fibers can further improve the brittleness of cement fiberboard. While reducing energy consumption, the preparation process can also effectively solve the problem that excessive pressure is easily generated in the fiberboard under high temperature conditions in the existing high-temperature and high-pressure curing process.

Objects made of waterglass-bonded sand, methods of making such objects and kits useful for making such objects. In some embodiments, an object according to the teachings herein is a final goods (as opposed to being an intermediate goods) such as a toy, a medallion, a building block, furniture, a wall, a portion of a sand castle and a sand castle.

Objects made of waterglass-bonded sand, methods of making such objects and kits useful for making such objects. In some embodiments, an object according to the teachings herein is a final goods (as opposed to being an intermediate goods) such as a toy, a medallion, a building block, furniture, a wall, a portion of a sand castle and a sand castle.

A method for manufacturing hydraulically hardening building materials, includes the steps of: providing concrete demolition waste with a maximum particle size of up to 150 mm as a starting material, mixing the starting material with water to form a feedstock slurry, introducing carbon dioxide or a precursor thereof into the feedstock slurry to form carbonated concrete fines in an amount from 1 to 100 wt.-% of the hardened binder contained in the starting material and to detach the concrete fines from the aggregate contained in the starting material to form a product slurry, and mixing the product slurry with a cement forming the building material, and use of the obtainable building material for manufacturing building structures as well as method for manufacturing a supplementary cementitious material slurry.

A method for manufacturing hydraulically hardening building materials, includes the steps of: providing concrete demolition waste with a maximum particle size of up to 150 mm as a starting material, mixing the starting material with water to form a feedstock slurry, introducing carbon dioxide or a precursor thereof into the feedstock slurry to form carbonated concrete fines in an amount from 1 to 100 wt.-% of the hardened binder contained in the starting material and to detach the concrete fines from the aggregate contained in the starting material to form a product slurry, and mixing the product slurry with a cement forming the building material, and use of the obtainable building material for manufacturing building structures as well as method for manufacturing a supplementary cementitious material slurry.