Chemical reaction devices involving acid and/or base, and related systems and methods, are generally described.

Chemical reaction devices involving acid and/or base, and related systems and methods, are generally described.

Reaction schemes involving acids and bases; reactors comprising spatially varying chemical composition gradients (e.g., spatially varying pH gradients), and associated systems and methods, are generally described.

Reaction schemes involving acids and bases; reactors comprising spatially varying chemical composition gradients (e.g., spatially varying pH gradients), and associated systems and methods, are generally described.

An embodiment includes a Class C fly ash (CFA) cementitious composition with a controllable setting time comprising at least one Class C fly ash; at least one alkali hydroxide; at least one source of phosphate; and water. Alternate embodiments include a Class C fly ash (CFA) cementitious composition with a solid activator comprising at least one Class C fly ash; at least one alkali carbonate; at least one source of phosphate; and water.

An embodiment includes a Class C fly ash (CFA) cementitious composition with a controllable setting time comprising at least one Class C fly ash; at least one alkali hydroxide; at least one source of phosphate; and water. Alternate embodiments include a Class C fly ash (CFA) cementitious composition with a solid activator comprising at least one Class C fly ash; at least one alkali carbonate; at least one source of phosphate; and water.

An embodiment includes a Class C fly ash (CFA) cementitious composition with a controllable setting time comprising at least one Class C fly ash; at least one alkali hydroxide; at least one source of phosphate; and water. Alternate embodiments include a Class C fly ash (CFA) cementitious composition with a solid activator comprising at least one Class C fly ash; at least one alkali carbonate; at least one source of phosphate; and water.

An embodiment includes a Class C fly ash (CFA) cementitious composition with a controllable setting time comprising at least one Class C fly ash; at least one alkali hydroxide; at least one source of phosphate; and water. Alternate embodiments include a Class C fly ash (CFA) cementitious composition with a solid activator comprising at least one Class C fly ash; at least one alkali carbonate; at least one source of phosphate; and water.

Chemical reaction devices involving acid and/or base, and related systems and methods, are generally described.

Chemical reaction devices involving acid and/or base, and related systems and methods, are generally described.