Described herein are processes for the activation of glass pozzolan as well as the activated product. Methods of using the activated product are also described.

Described herein are processes for the activation of glass pozzolan as well as the activated product. Methods of using the activated product are also described.

A method for manufacturing supplementary cementitious material and sequestering CO.sub.2 by carbonating concrete fines has the following steps: grinding the concrete fines obtained from crushed concrete demolition waste in a mill at a temperature from 1 to 10° C. above the water dew point in a carbonating atmosphere provided by a gas containing from 10 to 99 Vol.-% CO.sub.2, circulating the ground and partially carbonated concrete fines in a fluidized bed reactor in contact with the carbonating atmosphere, and withdrawing decarbonated gas and carbonated concrete fines.

A method for manufacturing supplementary cementitious material and sequestering CO.sub.2 by carbonating concrete fines has the following steps: grinding the concrete fines obtained from crushed concrete demolition waste in a mill at a temperature from 1 to 10° C. above the water dew point in a carbonating atmosphere provided by a gas containing from 10 to 99 Vol.-% CO.sub.2, circulating the ground and partially carbonated concrete fines in a fluidized bed reactor in contact with the carbonating atmosphere, and withdrawing decarbonated gas and carbonated concrete fines.

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.

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.

Disclosed are a room temperature curable quick-setting high-strength alkali-activated fly ash (AAFA) cementitious material and a preparation method thereof, belonging to the technical field of building materials. The raw materials include: in parts by mass, 30-50 parts of undisturbed fly ash, 50-70 parts of highly reactive ultra-fine fly ash, and 12-18 parts of sodium hydroxide. Specifically, the AAFA with fast setting and high strength for room temperature curing is prepared by pretreatment of fly ash with sodium hydroxide exciter, based on a premise that the raw material system and preparation process are simplified and feasible.

A method of carbonating cement powder and use thereof. An amount of water is supplied to an initial cementitious powder to create a moistened cementitious powder. Carbon dioxide is supplied to the moistened cementitious powder, while mechanically stirring the moistened cementitious powder, to cause a reaction of the carbon dioxide with the moistened cementitious powder to produce a carbonated cementitious material. The carbonated cementitious material is dried and ground to produce a carbonated cementitious powder. The carbonated cementitious powder may be combined with ordinary cement and various ingredients or additives, such as retarders, accelerators and extenders for use in well cementing applications. Methods for cementing casing, liners and remedial operations such as plugging back, and squeeze cementing are also provided. Methods for producing a low alkaline cement suitable for high CO.sub.2 gas wells are also provided. Methods to achieve a stable retarded cement used in higher temperatures are provided.

A method of carbonating cement powder and use thereof. An amount of water is supplied to an initial cementitious powder to create a moistened cementitious powder. Carbon dioxide is supplied to the moistened cementitious powder, while mechanically stirring the moistened cementitious powder, to cause a reaction of the carbon dioxide with the moistened cementitious powder to produce a carbonated cementitious material. The carbonated cementitious material is dried and ground to produce a carbonated cementitious powder. The carbonated cementitious powder may be combined with ordinary cement and various ingredients or additives, such as retarders, accelerators and extenders for use in well cementing applications. Methods for cementing casing, liners and remedial operations such as plugging back, and squeeze cementing are also provided. Methods for producing a low alkaline cement suitable for high CO.sub.2 gas wells are also provided. Methods to achieve a stable retarded cement used in higher temperatures are provided.

Cured cements, cement slurries, and methods of making cured cement and methods of using cement slurries are provided. The method of making a modified cement slurry includes adding particles comprising carbon nanotube sponges disposed on sacrificial templates to a cement slurry to form the modified cement slurry and allowing the sacrificial templates to disintegrate, thereby leaving the carbon nanotube sponges dispersed throughout the modified cement slurry.