Ramon Carrasquillo

US Patent:

55735886, Nov 12, 1996

Filed:

Jun 7, 1995

Appl. No.:

8/472559

Inventors:

Ramon L. Carrasquillo - Austin TX

Assignee:

Board of Regents, The University of Texas System - Austin TX

International Classification:

C04B 704
C04B 713
C04B 2804

US Classification:

106705

Abstract:

Class C fly ash containing cementitious mixtures for producing concretes that are resistant to sulfate-containing environments. Class C fly ash is intergound with portland cement clinker and gypsum to produce a cementitions mixture, which, when combined with water and an aggregate produces a hardened concrete that is resistant to sulfate environments. Alternatively, portland cement clinker and gypsum are first interground and the resultant mixture is admixed with Class C fly ash to produce a cementitious mixture. This cementitious mixture, in combination with water and an aggregate, produces a hardened concrete that has improved resistance to sulfate environments. In other aspects, a concrete that is stable in sulfate environments is produced by admixing portland cement, Class C fly ash and water containing a source of ions selected from the group consisting of sulfate and hydroxyl anions. The resultant concrete is capable of hardening in sulfate environments without the formation of such quantities of volume-expanding compositions in the hardened concrete as would cause the hardened concrete to undergo stress failure.