The present disclosure relates to a high-strength concrete and a preparation method thereof. The high-strength concrete includes lignin, recycled fine powder, cement, water, sand, gravels and a water reducing agent. The recycled fine powder is recycled fine powder of discarded concrete, and is prepared by separating solid waste of discarded buildings, then performing impurity removal and crushing processing, and grinding same by a ball mill into dust with a particle size of less than 0.16 mm. The lignin is discarded wood lignin, which is prepared by crushing the wood, stirring and extracting a sodium hydroxide aqueous solution with a mass concentration of 5% for 1 to 2 hours at the temperature of 80 DEG C. to obtain a black lignin alkali solution, adding a hydrochloric acid solution with a mass concentration of 30% into the alkali solution for stirring, and making the pH reduced to 7.0 for standing and layering.

A high-strength Portland cement slurry for ultra-high-temperature cementing, a preparation method therefor and an application thereof. In parts by weight, the composition of the cement slurry comprises: 100 parts of Portland cement, 4-6 parts of a high temperature anti-cracking material, 80-105 parts of a high-temperature reinforcing material, 70-78 parts of water, 0.5-1.5 parts of a dispersant, 1-3 parts of a fluid loss reducer, 0.5-2.5 parts of a retarder and 0.2-0.5 parts of a defoamer; the high-temperature reinforcing material is a combination of acid-washed quartz sand, metakaolin and aluminum sulfate, a combination of acid-washed quartz sand, metakaolin, feldspar and sodium sulfate, or a combination of acid-washed quartz sand, metakaolin, feldspar and calcium nitrite. The cement slurry has good settling stability, rapid strength development in low temperatures, high compressive strength of cement stone at a high temperature of 600° C., and stable development of long-term high-temperature compressive strength.

Method of efficiently manufacturing cement-SCM compositions having improved strength compared to cement-SCM compositions made using conventional methods. The cement-SCM compositions may contain: (A) a fine interground particulate component with (1) a hydraulic cement fraction and (2) a supplementary cementitious material (SCM) fraction; (B) a coarse particulate component comprised of coarse SCM particles not interground with the fine interground particulate component; and optionally (C) an auxiliary particulate component not interground with the fine interground particulate component or the coarse particulate component. A method of manufacturing a cement-SCM composition may be performed by: (A) intergrinding hydraulic cement (e.g., cement clinker) with one or more SCMs to form a fine interground particulate component; (B) blending, without intergrinding, the fine interground particulate component with a coarse particulate component comprised of coarse SCM particles; and optionally (C) further combining, without intergrinding, an auxiliary particulate component with the fine interground particulate component and the coarse particulate component.

A concrete slab (20) comprises conventional concrete and a combined reinforcement of both post-tension steel strands (22, 26) and fibres (29). The post-tension steel strands (22, 26): —have a diameter ranging from 5 mm to 20 mm, —have a tensile strength higher than 1700 MPa. The fibres (29) are present in a dosage ranging from 10 kg/m.sup.3 to 40 kg/m.sup.3 in case of steel fibres are in a dosage ranging from 1.5 kg/m.sup.3 to 9 kg/m.sup.3 in case of macro-synthetic fibres.

An activated pozzolan composition includes a fine interground particulate blend of an initially unactivated natural pozzolan and a supplementary cementitious material (SCM) different than the initially unactivated natural pozzolan. The initially unactivated natural pozzolan may include volcanic ash or other natural pozzolanic deposit having a moisture content of at least 3%, and the activated pozzolan composition can have a moisture content less than 0.5% The initially unactivated natural pozzolan may have a particle size less than 1 mm before intergrinding with the SCM. The SCM used to activate the initially unactivated natural pozzolan can be initially coarse or granular with a size greater than 1-3 μm and may include granulated blast furnace slag, steel slag, other metallurgical slag, pumice, limestone, fine aggregate, shale, tuff, trass, geologic material, waste glass, glass shards, basalt, sinters, ceramics, recycled bricks, recycled concrete, refractory materials, other waste industrial products, sand, or natural mineral.

A concrete composition that includes (i) a treated palm oil fuel ash, wherein the treated palm oil fuel ash is the only binder present, (ii) a fine aggregate, (iii) a coarse aggregate, and (iv) an alkali activator containing an aqueous solution of sodium hydroxide and sodium silicate. A cured concrete made from the concrete composition is also disclosed with advantageous compressive strength properties.

Methods of forming a carbon fiber reinforced carbon foam are provided. Such a method may comprise heating a porous body composed of a solid material comprising covalently bound carbon atoms and heteroatoms and having a surface defining pores distributed throughout the solid material, in the presence of an added source of gaseous hydrocarbons. The heating generates free radicals in the porous body from the heteroatoms and induces reactions between the free radicals and the gaseous hydrocarbons to form covalently bound carbon nanofibers extending from the surface of the solid material and a network of entangled carbon microfibers within the pores the porous body, thereby forming a carbon fiber reinforced carbon foam. Carbon fiber reinforced carbon foams and ballistic barriers incorporating the foams are also provided.

A permeable pavement system including a permeable pavement composition and a related method are provided. The permeable pavement system includes a first layer of a permeable pavement composition including a quantity of a first permeable pavement material and a quantity of cured carbon fiber composite material (CCFCM) incorporated therewith, the first layer defining a first surface; and a second layer of a second permeable pavement material deposited over a substantial entirety of and covering the first surface of the first layer of the permeable pavement composition, wherein the first layer interfaces with the second layer to at least strengthen the permeable pavement system.

A method for increasing the force required to separate a solidified deformable material into at least two portions includes adding unmodified fibers and/or modified fibers having high tensile strength, high modulus of elasticity and high shock resistance to the deformable material; the modified fibers having surfaces with integral protuberances and/or attached silica particles emanating from each surface. The modified fibers, when mixed with the deformable material, ultimately form a solidified matrix having increased tensile strength (when compared to the solidified material without having the modified fibers) and increased resistance to separating into two or more portions when a force impacts or strikes a portion of the solidified deformable material.

In the present disclosure, a cement board is disclosed. The cement board comprises a cement core having a first surface and a second surface opposite the first surface. The cement core comprises a binder, a lightweight aggregate, and a combustible additive, wherein the combustible additive is present in an amount of greater than 0 wt. % to less than 0.5 wt. % based on the weight of the cement core. The cement board passes CAN/ULC-S114:2018 and/or ASTM E136-19a.