EXPERIMENTS WITH ALKALI-SILICA REACTIVE CONSTITUENTS OF SAND -GRAVEL AGGREGATE
A PILOT SERIES OF EXPERIMENTS INVESTIGATED THE EFFECT OF ALKALI-SILICA REACTIVE CONSTITUENTS IN A SAND-GRAVEL AGGREGATE IN THE SEALED MOIST-STORAGE AND THE CONROW CYCLE MORTAR BAR EXPANSION TESTS. THE HIGH ALKALI-SILICA REACTIVE SAND-GRAVEL USED PRODUCED DELETERIOUS EXPANSION IN BOTH THE SEALED MOIST-STORAGE AND THE CONROW CYCLE MORTAR BAR TEST. THE ALKALI-SILICA REACTIVE PARTICLES WERE REMOVED FROM THE AGGREGATE, AND THE PROCESSED AGGREGATE WAS TESTED. THE REMOVAL OF THE ALKALI-SILICA REACTIVE PARTICLES REDUCED EXPANSION IN THE SEALED MOIST-STORAGE TEST TO WITHIN SEVERAL TEST LIMITS. IN THE CONROW CYCLE TEST, EXPANSION WAS REDUCED BUT A SIGNIFICANT AMOUNT OF EXPANSION REMAINED. THE REMAINING EXPANSION APPEARS TO BE DUE TO THE CHARACTERISTIC CEMENT-AGGREGATE REACTION OF SAND-GRAVEL AGGREGATES. THE SMALL AMOUNT OF ALKALI REACTIVE MATERIAL REMAINING IN THE AGGREGATE MIGHT CONTRIBUTE TO THIS EXPANSION. THE ALKALI REACTIVE CONSTITUENTS WERE BLENDED WITH AN INNOCUOUS SOUTH PLATTE RIVER AGGREGATE WHICH DOES NOT PRODUCE DELETERIOUS EXPANSION IN EITHER OF THE TESTS. THE BLENDED SOUTH PLATTE RIVER AGGREGATE PRODUCED SOME EXPANSION IN BOTH THE TESTS. THESE TESTS INDICATE THAT ALKALI-SILICA REACTION IS A MAJOR FACTOR IN THE CEMENT-AGGREGATE REACTION WITH ALKALI-SILICA REACTIVE SAND-GRAVEL AGGREGATES. THE PROBLEM OF CEMENT- AGGREGATE REACTION WITH NONALKALI-REACTIVE SAND-GRAVEL AGGREGATES REQUIRES FURTHER INVESTIGATION. THESE TESTS ALSO INDICATE THAT THE CONROW CYCLE MORTAR BAR EXPANSION TEST IS SENSITIVE TO ALKALI-SILICA REACTION.
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Supplemental Notes:
- Paper sponsored by Committee on Durability of Concrete--Physical Aspects and presented at the 45th Annual Meeting. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
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Authors:
- DePuy, G W
- Publication Date: 1966
Media Info
- Media Type: Digital/other
- Features: References; Tables;
- Pagination: pp 41-49
- Monograph Title: Aggregates for concrete
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Serial:
- Highway Research Record
- Issue Number: 124
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Aggregates; Alkali aggregate reactions; Alkali silica reactions; Bars (Building materials); Expansion; Experiments; Gravel; Handling and storage; Moisture content; Mortar; Reactive aggregates; Sand; Storage facilities; Testing
- Old TRIS Terms: Cement-aggregate reaction; Conrow cycle; Deleterious expansion; Moist condition; Mortar bar expansion
- Subject Areas: Freight Transportation; Geotechnology; Highways; Pavements; Terminals and Facilities;
Filing Info
- Accession Number: 00206231
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Nov 18 1994 12:00AM