Provided herein are systems for carbonation curing and CO.sub.2 mineralization of concrete composites and methods of manufacturing a carbonated concrete composite. A method of manufacturing a carbonated concrete composites includes contacting concrete with CO.sub.2-containing gas streams in the carbonation reactor having a gas stream inlet and an outlet to provide optimal gas flow distribution and gas velocity. The concrete precursor includes a binder, one or more aggregates, and water. A gas stream is received at the carbonation reactor. The gas stream includes carbon dioxide. The concrete precursor is maintained at a suitable temperature in the carbonation reactor to thereby react the concrete precursor with the gas stream to produce carbonate minerals in the carbonated concrete composite.

Cement compositions containing a hydraulic cement, a synthetic phyllosilicate (e.g. Laponite®), and silica flour. The cement compositions may optionally include other additives such as an expandable agent, a defoamer, and a fluid loss controller. Cement slurries and wellbore cements made therefrom are also specified. The inclusion of the synthetic phyllosilicate has enhanced the mechanical strength, improved the density homogeneity, as well as decreased the permeability of the wellbore cement, making it suitable for cementing oil and gas wells under high pressure and high temperature (HPHT) conditions.

A coated nonwoven mat includes a nonwoven base layer and a coating layer. The nonwoven base layer is formed from a plurality of fibers held together by a binder and includes a first surface and a second surface. The coating layer includes a coating composition comprising a binder component, a filler, and one or more performance modifiers. The coated nonwoven mat has an average Gurley porosity of at least 10 seconds and an average hydrostatic head performance of at least 10 mbar.

Cement compositions containing a hydraulic cement, a synthetic phyllosilicate (e.g. Laponite), and silica flour. The cement compositions may optionally include other additives such as an expandable agent, a defoamer, and a fluid loss controller. Cement slurries and wellbore cements made therefrom are also specified. The inclusion of the synthetic phyllosilicate has enhanced the mechanical strength, improved the density homogeneity, as well as decreased the permeability of the wellbore cement, making it suitable for cementing oil and gas wells under high pressure and high temperature (HPHT) conditions.

A ceramic porous body comprising: skeleton portions including an aggregate and at least one binding material; and pore portions formed between the skeleton portions, the pore portions being capable of allowing a fluid to flow therethrough. In the ceramic porous body, the pore portions have a pore volume ratio of pores having a pore diameter of from 1 to 10 m, of 45% or more, and a ratio of a contact area between the aggregate and the binding material to a surface area of the binding material of from 20 to 60%.

A ceramic porous body comprising: skeleton portions including an aggregate and at least one binding material; and pore portions formed between the skeleton portions, the pore portions being capable of allowing a fluid to flow therethrough. In the ceramic porous body, the pore portions have a pore volume ratio of pores having a pore diameter of from 1 to 10 m, of 45% or more, and a ratio of a contact area between the aggregate and the binding material to a surface area of the binding material of from 20 to 60%.