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.

A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement:SF:NP in the cementitious blend composition lies in the range of (24-63):(5-44):(32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water to the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.

A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement:SF:NP in the cementitious blend composition lies in the range of (24-63):(5-44):(32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water to the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.

Methods of preparing engineered cementitious composite precursors include carbonating a fly ash comprising >about 25% by weight of calcium oxide (CaO) and having a water content of >about 12% to <about 18% by weight of water by exposing the fly ash to a first gas stream comprising carbon dioxide to form a carbonated fly ash. A steel slag is also carbonated that comprises>about 40% by weight of calcium oxide (CaO) and having a water content of >about 12% to <about 18% by weight of water by exposing the steel slag to a second gas stream comprising carbon dioxide to form a carbonated steel slag. The carbonated fly ash and the carbonated steel slag are suitable for use as engineered cementitious composite precursors in a bendable engineered cementitious composite composition that further comprises Portland cement, a polymeric fiber, and a superplasticizer.

Methods of preparing engineered cementitious composite precursors include carbonating a fly ash comprising >about 25% by weight of calcium oxide (CaO) and having a water content of >about 12% to <about 18% by weight of water by exposing the fly ash to a first gas stream comprising carbon dioxide to form a carbonated fly ash. A steel slag is also carbonated that comprises>about 40% by weight of calcium oxide (CaO) and having a water content of >about 12% to <about 18% by weight of water by exposing the steel slag to a second gas stream comprising carbon dioxide to form a carbonated steel slag. The carbonated fly ash and the carbonated steel slag are suitable for use as engineered cementitious composite precursors in a bendable engineered cementitious composite composition that further comprises Portland cement, a polymeric fiber, and a superplasticizer.

The present invention relates to fiber cement flooring products. In particular, the present invention provides fiber cement flooring products, at least comprising cement and fibers, characterized in that these fiber cement flooring products comprise amorphous silica in an amount of between about 2 weight % and about 15 weight % compared to the total dry weight of the fiber cement composition of said fiber cement flooring product. The present invention further relates to methods for the production of such fiber cement flooring products as well as uses of such fiber cement flooring products in the building industry. The present invention further relates to fiber cement formulations and fiber cement materials, which are suitable for the production of fiber cement products for flooring applications.

The present invention relates to fiber cement flooring products. In particular, the present invention provides fiber cement flooring products, at least comprising cement and fibers, characterized in that these fiber cement flooring products comprise amorphous silica in an amount of between about 2 weight % and about 15 weight % compared to the total dry weight of the fiber cement composition of said fiber cement flooring product. The present invention further relates to methods for the production of such fiber cement flooring products as well as uses of such fiber cement flooring products in the building industry. The present invention further relates to fiber cement formulations and fiber cement materials, which are suitable for the production of fiber cement products for flooring applications.

Compositions that include a polymer and an aldaric acid, such as glucaric acid, are disclosed. The compositions may include polyvinyl alcohol and glucaric acid. The compositions may also include polyacrylonitrile and glucaric acid. In addition, the compositions may further include lignin. Also disclosed are fibers including the compositions, methods of making the fibers, and uses of the fibers.

A roof tile containing fibers which satisfy the following requirements (1) to (3): (1) to have an average fiber diameter of 50 μm or less; (2) to have an aspect ratio of 50 to 2000; and (3) to have three or less buckled portions per fiber.

A roof tile containing fibers which satisfy the following requirements (1) to (3): (1) to have an average fiber diameter of 50 μm or less; (2) to have an aspect ratio of 50 to 2000; and (3) to have three or less buckled portions per fiber.