George D Guthrie

US Patent:

59553723, Sep 21, 1999

Filed:

Apr 14, 1998

Appl. No.:

9/060513

Inventors:

George D. Guthrie - Santa Fe NM
J. William Carey - Santa Fe NM

Assignee:

The Regents of the University of California - Los Alamos NM

International Classification:

G01N 2191

US Classification:

436 28

Abstract:

A method using concentrated aqueous solutions of sodium cobaltinitrite and a rhodamine dye is described which can be used to identify concrete that contains gels formed by the alkali-silica reaction (ASR), and to identify degraded concrete which results in a porous or semi-permeable paste due to carbonation or leaching. These solutions present little health or environmental risk, are readily applied, and rapidly discriminate between two chemically distinct gels; K-rich, Na--K--Ca--Si gels are identified by yellow staining, and alkali-poor, Ca--Si gels are identified by pink staining.

US Patent:

57390355, Apr 14, 1998

Filed:

Nov 7, 1996

Appl. No.:

8/745118

Inventors:

George D. Guthrie - Santa Fe NM
J. William Carey - Santa Fe NM

Assignee:

The Regents of the University of California - Los Alamos NM

International Classification:

G01N 2191

US Classification:

436 28

Abstract:

A method using concentrated aqueous solutions of sodium cobaltinitrite and rhodamine B is described which can be used to identify concrete that contains gels formed by the alkali-silica reaction (ASR). These solutions present little health or environmental risk, are readily applied, and rapidly discriminate between two chemically distinct gels; K-rich, Na--K--Ca--Si gels are identified by yellow staining, and alkali-poor, Ca--Si gels are identified by pink staining.