Pulverulent ash composition as a portland cement substitute for improving concrete products and method

A method of forming a dry pulverulent ash composition as a portland cement substitute comprising the steps of providing a dry pulverulent fly ash,

• reducing or maintaining the moisture content of the fly ash at a level of 5% or less, by weight,
• admixing an oxidizer with fly ash in an amount effective for converting sulfur compounds that are present in the fly ash to the sulfate form,
• maintaining the oxidizer in a dry state of 5% moisture or less by weight when the oxidizer is admixed with the fly ash, and
• storing the pulverulent ash and oxidizer as to maintain said ash and oxidizer in a dry unreacted state during storage,
• such that concrete products formed from said ash composition have a compression strength significantly greater than an equivalent concrete product in which portland cement is used in place of said composition.

A dry pulverulent ash composition that is sufficiently environmentally stable to be packaged or shipped dry for use as a portland cement substitute that increases the strength of a concrete product formed therefrom, said composition comprising,

• a dry pulverulent fly ash having a moisture content of 5% or less that is derived from the burning of coal,
• an oxidizer in the amount of about 0.05% to about 0% by weight admixed therewith, said oxidizer converting sulfur compounds that are present in the ash to the sulfate form to thereby increase the compression strength of a finished concrete product containing said composition,
• the oxidizer comprising at least one member selected from the group consisting of sodium nitrite, sodium perborate, sodium percarbonate, sodium hypochlorite, calcium hypochlorite, calcium percarbonate, hydrogen peroxide, calcium peroxide, sodium peroxide, ethylene oxide and propylene oxide and,
• portland cement in pulverulent form admixed therewith,
• storing the pulverulent ash and oxidizer so as to maintain said ash and oxidizer in the dry unreacted state during storage,
• such that a finished concrete product formed from said ash composition has a compression strength up to about 10% greater than an equivalent concrete product without said ash composition present therein.

A method of forming a dry pulverulent ash composition as a portland cement substitute comprising,

• providing a dry pulverulent fly ash that is derived from the burning of coal, reducing or maintaining the moisture content of the fly ash at a level of 5% or less, by weight,
• admixing an oxidizer with fly ash in an amount of about 0.05% to about 10% by weight of the composition for converting sulfur compounds that are present in the fly ash to the sulfate form,
• maintaining the oxidizer in a dry state of 5% moisture or less by weight when the oxidizer is admixed with the fly ash, by admixing the oxidizer with a stream of air that has passed through a dryer for reducing the moisture content of the air such that the oxidizer and fly ash remain in said dry state so as to be in an unreacted state during storage,
• admixing a minor amount of portland cement with the fly ash and oxidizer and storing the pulverulent ash and oxidizer so as to maintain said ash and oxidizer in a dry unreacted state during storage.