A method for making a low cost, lightweight carbon aggregate from coal at, above, or below atmospheric pressure, and a lightweight concrete composition utilizing the lightweight carbon aggregate is described.

The method is for use with a substrate having a plurality of parallel channels extending therethrough. In the method, the steps comprise: filling a selected plurality of the channels with a granular material; and consolidating the granular material through heat. The selected plurality of channels is selected to produce a wall that separates the substrate into: a first portion having a first plurality of the parallel channels extending therethrough; and a second portion having a second plurality of the parallel channels extending therethrough.

The method is for use with a substrate having a plurality of parallel channels extending therethrough. In the method, the steps comprise: filling a selected plurality of the channels with a granular material; and consolidating the granular material through heat. The selected plurality of channels is selected to produce a wall that separates the substrate into: a first portion having a first plurality of the parallel channels extending therethrough; and a second portion having a second plurality of the parallel channels extending therethrough.

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.

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 variety of methods and compositions are disclosed, including, in one embodiment a method a cementing in a subterranean formation comprising: providing a set-delayed cement composition comprising water, pumice, hydrated lime, and a set retarder; foaming the set-delayed cement composition; activating the set-delayed cement composition; introducing the set-delayed cement composition into a subterranean formation; and allowing the set-delayed cement composition to set in the subterranean formation. Additional methods, foamed set-delayed cement composition, and systems for cementing are also provided.

Exemplary embodiments relate to a batch for producing an unshaped refractory ceramic product, to a method for producing a fired refractory ceramic product, to a fired refractory ceramic product and to the use of an unshaped refractory ceramic product.

A structural lightweight concrete composition comprising cement, a fine aggregate such as sand, a natural coarse aggregates, such as limestone, scoria or perlite or mixtures thereof, a synthetic coarse aggregate comprising a polymeric material, such as polypropylene beads, an industrial waste byproduct in the form of fine particles, such as silica fume or heavy oil ash, a superplasticizer, such as a polycarboxylate ether and water demonstrating lower thermal conductivity and sufficient compressive strength. Concrete products made therefrom and methods for producing such products are also provided.

A structural lightweight concrete composition comprising cement, a fine aggregate such as sand, a natural coarse aggregates, such as limestone, scoria or perlite or mixtures thereof, a synthetic coarse aggregate comprising a polymeric material, such as polypropylene beads, an industrial waste byproduct in the form of fine particles, such as silica fume or heavy oil ash, a superplasticizer, such as a polycarboxylate ether and water demonstrating lower thermal conductivity and sufficient compressive strength. Concrete products made therefrom and methods for producing such products are also provided.

Implementations described and claimed herein provide a process for creating a low-buoyancy cellular concrete that may include cement, water, and various surfactants including hydrophilic additives to produce the low-buoyancy cellular concrete. The low-buoyancy cellular concrete wet mix maintains its cellular properties while it is placed and cures. After curing, water may be absorbed into the low buoyancy cellular concrete via a combination of physical and chemical characteristics. An open cell structure of capillaries facilitates wicking action of water into the low buoyancy cellular concrete via capillary channeling (through the cementitious matrix between the micro-bubbles, and in some cases into the micro-bubbles as well). Further, the hydrophilic additive in the foam surfactant facilitates absorption of water into the low buoyancy cellular concrete through diminished surface tension at an interface of the cellular concrete and a body of water and at and between the microbubbles.