Lightweight concrete

An emulsion for use in manufacture of a lightweight aggregate wherein said emulsion comprises an aqueous phase, a surfactant, and a dispersed phase comprising a binding agent, said emulsion also including a dispersion of transition metal ions in an amount in excess of 10% by dry weight, wherein the transition metal ions are ferric ions.

A method of manufacture of a lightweight aggregate comprising emulsifying a binder in an aqueous phase, dispersing a transition metal ion in the aqueous phase so that the emulsion comprises at least 10% by weight of solids of a transition metal ion comprising the ferric ion, and coating a lightweight porous aggregate with the emulsion.

A lightweight aggregate comprising free-flowing particles of polymer foam coated with a binding agent, said binding agent having dispersed therein, in total, at least 10% by weight thereof of one or more transition metal ions.

An emulsion for use in manufacture of a lightweight aggregate wherein said emulsion comprises an aqueous phase, a surfactant, and a dispersed phase comprising a binding agent, said emulsion also including a dispersion of transition metal ions in an amount in excess of 10% by dry weight.

A method of manufacture of a lightweight aggregate comprising emulsifying a binder in an aqueous phase, dispersing a transition metal compound in the aqueous phase so that the emulsion comprises at least 10% by weight of solids of a transition metal ion, and coating a lightweight porous aggregate with the emulsion.