The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 31, 2004
Filed:
Oct. 15, 2002
Philip Souza Zacarias, Mississauga, CA;
David Bridson Oates, Kettleby, CA;
Lafarge Canada Inc., Quebec, CA;
Abstract
Concrete's durability to freeze-thaw cycles is dependent on its level of air entrainment, the appropriate level of which is achieved with the aid of surface active or air entraining agents. These agents promote the fragmentation of large air voids into smaller ones and stabilize air voids in the concrete. The carbon matter found in fly ash when used as a pozzolanic component of concrete, adsorbs the air entraining agents, reduces the air voids and concrete's ability to withstand many freeze-thaw cycles. This invention teaches a process for a partial removal of the carbon from the coal ash, used in concrete, through a partial combustion of only a fine carbon fraction of the carbon residue of the coal ash responsible for adsorbing the air entraining agents, in a reactor with a controlled ignition system. The process of the invention thus limits the adsorption of the air entraining agents and improves the freeze-thaw properties of the concrete produced.