Geopolymer expansion additive
A composition that controls and delays generation of foam in geopolymer pastes, mortars and concretes. Embodiments include a one-part anhydrous formula for the production of geopolymer foam that requires only the addition of water. The formula includes specific and variably designed admixtures that manage a time release delivery of alkali activation components, foaming agents, and blends thereof.
1. A geopolymer having an embedded time-release control of chemically reactive, activation components the time-controlled activation of geopolymer foam pastes, mortars, and concretes, comprising:
(1) at least one dry powdered component;
(2) at least one alkaline activator component;
(3) at least one non-reactive aggregate;
(4) water;
(5) at least one foaming agent; and
(6) an admixture including at least one aggregate coated with at least one coat of wetting and sticking agent which is in turn coated by at least one reactive coating media, which is in turn coated by at least one non-reactive coating media to create a protective shell around said reactive coating media and provide a controlled time-release delivery of said reactive components, whereby said geopolymer holds an initial wet-batch volume prior to the production of foam and the initial setting of said geopolymer in a dormant period between zero and 20 minutes, and once fully expanded through the production of foam reaches volumes of 1.5 to 4 times the dormant, pre-expanded volume; and
wherein the foam density of a fully cured product made from said composition has a thermal resistance (IP) R rating from 0.5 R per inch to 6 R per inch, can withstand 1200 degrees F. without suffering structural decomposition or releasing toxic gasses.
2. The geopolymer of claim 1 , wherein said at least one dry powdered component is selected from the group consisting of type N pozzolans, Class F fly ash, Class C fly ash, Portland cement, Gypsum, GGBFS, silica fume, rice hull ash, ground silica, ground fired clay bisque, milled soda lime glass, and talc, and combinations thereof.
3. The geopolymer of claim 1 , further including at least one non-reactive aggregate selected from the group consisting of expanded perlite, expanded glass aggregate, expanded ceramic aggregate, pumice, silica sand, expanded polystyrene beads, recycled polystyrene aggregate, and combinations thereof.
4. The geopolymer of claim 1 , wherein said aggregate of said admixture component is a reactive aggregate coated with a layer of shellac, which is in turn coated with a layer of a lacquer coating binder, which is then coated with a layer of lacquer, and then finally dried.
5. The geopolymer of claim 1 , wherein said aggregate of said admixture component further includes a final coat of a non-reactive coating media and a semi-permanent coating material.