00771114

Component

https://doi.org/10.3141/1668-10

http://scholar.google.com...arey&publication_year=1999

A geochemical method for staining various products of the alkali-silica reaction is presented. The method is based on both the composition of alkali-silica-reaction (ASR) gel and one of its properties (the ability to exchange cations with a fluid). Specifically, one stain (sodium cobalt nitrite) reacts with exchangeable potassium in the gel to form a bright yellow precipitate on the gel surface. The other class of stains (a variety of rhodamine compounds) reacts with calcium-rich portions of the gel (and, for some compounds, with other calcium-rich components of the concrete) to form a pink-stained gel. The significance of the pink staining is twofold. First, it can provide a high contrast to the yellow-stained gels, making them easier to observe. Second, some rhodamine compounds react predominantly with calcium-rich ASR gels. Some aspects of staining by rhodamine remain the subject of continued study and may be useful for a more detailed understanding of ASR progression and other deterioration mechanisms. However, a positive diagnosis of ASR is indicated by the presence of yellow-stained gel within aggregate, at the aggregate-paste interface, along fractures, or in air voids. The technique can be used as a rapid field screening method or as a useful aid for detailed petrographic examinations.

This paper appears in Transportation Research Record No. 1668, Concrete in Pavements and Structures.

English

p. 68-71

1999

Transportation Research Record

0309070635

Figures (1) ; References (7)

Alkali silica reactions; Concrete; Deterioration; Field tests; Gels; Geochemistry; Petrography

Staining (Tests)

Highways; Materials; I32: Concrete

TRIS, TRB, ATRI

Oct 7 1999 12:00AM

• BOND INTERACTION BETWEEN CONCRETE PAVEMENT AND LEAN CONCRETE BASE
• CONCRETE CAPILLARY POROSITY AS IT RELATES TO DURABILITY OF PAVEMENTS BUILT WITH ALKALI-SILICA-REACTIVE AGGREGATES
• CRACKING DAMAGE/DETERIORATION AND REHABILITATION CONSIDERATIONS OF SOME BIRMINGHAM, ALABAMA, INTERSTATE BRIDGE DECKS
• EFFECT OF MICROCRACKING ON DURABILITY OF HIGH-STRENGTH CONCRETE
• IMPACT OF PROCESSED CELLULOSE FIBERS ON PORTLAND CEMENT CONCRETE PROPERTIES
• INFLUENCE OF ALKALINE EARTH SILICATE ADMIXTURE ON DURABILITY OF PENNSYLVANIA TURNPIKE BRIDGES
• INFLUENCE OF TOTAL AGGREGATE GRADATION ON FREEZE-THAW DURABILITY AND OTHER PERFORMANCE MEASURES OF PAVING CONCRETE
• INVESTIGATION OF DESIGN PARAMETERS AFFECTING TRANSVERSE CRACKING IN JOINTED CONCRETE PAVEMENTS
• MITIGATION OF ALKALI-SILICA REACTION IN PAVEMENT PATCH CONCRETE THAT INCORPORATES HIGHLY REACTIVE FINE AGGREGATE
• PROPOSED GUIDELINES FOR THE PREVENTION OF ALKALI-SILICA REACTION IN NEW CONCRETE STRUCTURES
• USE OF A LITHIUM-BEARING ADMIXTURE TO SUPPRESS EXPANSION IN CONCRETE DUE TO ALKALI-SILICA REACTION
• VERY-EARLY-STRENGTH LATEX-MODIFIED CONCRETE OVERLAY
• VIRGINIA'S APPROACH TO EVALUATION OF CONCRETE RESISTANT TO ALKALI-SILICA REACTIONS