TESTS USED BY THE BUREAU OF RECLAMATION FOR IDENTIFYING REACTIVE CONCRETE AGGREGATES

A DELETERIOUS DEGREE OF ALKALI-REACTIVITY IS INDICATED IF THE AGGREGATES (1) ARE SHOWN TO CONTAIN PROPORTIONS OF REACTIVE SUBSTANCES IN EXCESS OF 0.25 TO 5.0 PERCENT BY WEIGHT, DEPENDING UPON THE IDENTITY OF THE REACTIVE CONSTITUENTS, (2) ARE CHARACTERIZED BY A RATIO OF SC/RC GREATER THAN 1.0 AS A RESULT OF THE CHEMICAL TEST, (3) CAUSE EXPANSION OF THE MOIST-STORED MORTAR SPECIMENS IN EXCESS OF 0.1 PERCENT LINEARLY IN A YEAR WITH THE HIGH ALKALI CEMENT, (4) CAUSE EXPANSION OF THE CONCRETE BEAMS IN EXCESS OF 0.07 PERCENT LINEARLY IN 310 CYCLES OF WETTING AND DRYING, OR (5) ARE KNOWN TO BE ASSOCIATED WITH THE CHARACTERISTIC EXPANSIVE DETERIORATION OF CONCRETE IN STRUCTURES. THE MORTAR-BAR EXPANSION TEST HAS FORMED THE MOST RELIABLE AND QUANTITATIVE MEANS OF EVALUATING ALKALI REACTIVITY OF AGGREGATES IN THE BUREAU OF RECLAMATION TESTING PROGRAM. THE BUREAU EXAMINATION INVOLVES THE FOLLOWING FIVE TESTS BEFORE AN AGGREGATE IS USED IN CONSTRUCTION: (1) PETROGRAPHIC ANALYSIS OF AGGREGATE, (2) CHEMICAL TESTING OF AGGREGATE, (3) MORTAR- BAR EXPANSION TEST, (4) CONCRETE WETTING AND DRYING AND (5) EXAMINATION OF CONCRETE IN STRUCTURES.

• Supplemental Notes:
  • Vol 48, pp 1071-1107
• Authors:
  • Mielenz, R C
  • Witte, L P
• Publication Date: 1948

Media Info

• Serial:
  • American Soc Testing & Materials Proc

Subject/Index Terms

• TRT Terms: Alkali aggregate reactions; Beams; Chemical tests; Concrete; Concrete aggregates; Concrete tests; Deterioration; Durability; Expansion; Geological surveying; Moisture content; Mortar; Petrography; Wetting and drying tests
• Uncontrolled Terms: Concrete beams
• Old TRIS Terms: Petrographic investigations
• Subject Areas: Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00212662
• Record Type: Publication
• Source Agency: Highway Research Board Bibliography
• Files: TRIS
• Created Date: Jul 15 1994 12:00AM