A method for forming cement-based cementitious material includes: pouring a cement paste into a mold; applying an electrical current to the cement paste to perform an electro-osmotic reaction; and transferring the reacted cement paste into a water tank for curing, thereby obtaining a functionally graded cement-based cementitious material. A pair of electrodes is placed in the mold and connected to an external power source. The compressive strength of the functionally graded cement-based cementitious material in the middle is lower than that at either of both ends.

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.

Compositions and methods of forming compositions for a controlled low strength material (CLSM) comprising heavy oil fuel ash (HOFA) and recycled concrete powder (RCP) waste with natural and recycled aggregates and water are provided. In some embodiments, small quantities of Portland cement are also utilized. The recycled concrete powder contains primarily calcite and quartz. The CLSM can be used as a flowable compacted fill in structural and non-structural construction applications.

The invention provides cement additives comprising calcium sulfate and silica which are derived from a material comprising perovskite and silica, along with cements and cementitious products comprising the cement additives. The invention also provides methods for the making the cement additive and cements and cementitious products comprising the cement additives.

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.

An inorganic fiber toughened inorganic composite artificial stone panel and a preparation method thereof are disclosed. The panel includes a surface layer and a toughened base layer. The surface layer includes the the following components in parts by weight: 40-70 parts of quartz sand, 10-30 parts of quartz powder, 20-45 parts of inorganic active powder, 0.5-4 parts of pigment, 0.3-1 parts of water reducing agent and 3-10 parts of water. The toughened base layer includes the following components in parts by weight: 40-60 parts of inorganic active powder, 45-65 parts of sand, 0.8-1.5 parts of water reducing agent, 6-14 parts of water, 0.4-2 parts of inorganic fiber and 0.8-2.5 parts of toughener.

A light weight geopolymer concrete, having a specific gravity less than 2.0, more typically between 1 and 1.3, is provided that has compressive strength comparable to or greater than ordinary Portland concrete. The light weight geopolymer concrete has low shrinkage, expansion, and cracking, and substantially no loss of compressive strength when exposed to high temperatures of 800° C. or greater, as would occur in a fire. To be useful as a load bearing member for general applications, such as residential housing, the compressive strength of the light-weight geopolymer concrete should be at least 10 MPa, preferably greater than 12 MPa, for example greater than 15 MPa. For more demanding uses, the compressive strength should be near or at the compressive strength of concrete, that is, greater than 20 MPa, preferably greater than 30 MPa, and optimally greater than 35 MPa. To be useful during and after a fire, the strength must not be reduced by more than 20%, preferably not less than 10%, optimally not reduced at all when exposed to heat up to 800° C. Embodiments of the invention include low-density high-temperature-resistant geopolymer concrete which increases load bearing strength when exposed to temperatures above 400° C., preferably at 800° C. Key constituents for forming most embodiments include a geopolymer source such as fly ash, a cement-coated expanded vermiculite, a fiber such as wollastonite, and soluble silicates such as alkali silicates.

An article includes a body having a first phase comprising alpha silicon carbide and pores contained in the body; the pores having a mean spacing distance of at least 205 microns and not greater than 300. The body can have a ballistic.

Materials and methods for a rapid and effective way to create a carbon negative self-healing construction material are described. The construction material uses sand aggregates, a trace amount of catalyst, a small dosage of scaffolding material with a crosslinking agent, and a calcium source. The curing is performed at a high temperature for a short period or at room temperature for a long period. The catalyst-driven method to bridge the sand particles results in a dense, stiff, strong, and tough structural material, which upon exposure to calcium source and CO.sub.2 heals itself repeatably.

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.