THE GROWTH OF BASIC RESEARCH ON THE PROPERTIES OF CONCRETE IN THE PCA LABORATORIES
SINCE 1930, EMPIRICAL RESEARCH IN THE PORTLAND CEMENT ASSOCIATION LABORATORIES HAS GIVEN WAY TO A MORE FUNDAMENTAL APPROACH AND A QUEST FOR NUMBERS HAVING MEANING WITH RESPECT TO STRUCTURE. SCIENTIFIC RESEARCH ON CEMENT CHEMISTRY INDICATED THE POSSIBLE EXISTENCE OF SPECIFIC STRUCTURAL FEATURES THAT WOULD EXPLAIN OBSERVED PROPERTIES OF CONCRETE. BLEEDING AND RHEOLOGICAL PROPERTIES SUPPORTED THIS THEORY. STUDIES FOLLOWED ON THE MECHANISM OF SHRINKING AND SWELLING, THE ROLE OF CAPILLARY FORCE AND OF VISCOUS FRICTION IN BLEEDING AND SHRINKAGE STRESS AND CREEP. APPLICATION OF COLLOID AND CAPILLARY THEORIES TO CONCRETE RESEARCH WAS AN IMPORTANT STEP. A MANY-FACETED PROGRAM OF CEMENT PASTE AND CONCRETE WAS BUILT UP WITH THE PHYSICAL STRUCTURE OF HARDENED PASTE AS THE BACKBONE. THE FIRST PAPER ON MULTIMOLECULAR ADSORPTION, IN 1938, LED TO THE BET METHOD OF MEASUREMENT OF INTERNAL SURFACE AREA. THIS IN TURN LED TO THE STUDY OF ENERGETICS OF ADSORPTION. CONCRETE PROPERTIES COULD FINALLY BE INTERPRETED IN TERMS OF NUMBERS FOUND INSIDE CEMENT PASTE. THE CALORIMETER, X-RAY AND ELECTRON MICROSCOPES PROVIDED ADDITIONAL NUMBERS. STEREOMICROGRAPHS, WHICH ENABLE THE ACTUAL STRUCTURE OF THE HARDENED CEMENT PASTE TO BE SEEN, HAVE NOT REQUIRED A MAJOR CHANGE IN CONCEPTS DEVELOPED BY THE INDIRECT METHODS OF EXPLORATION.
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Supplemental Notes:
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Corporate Authors:
Highway Research Board (HRB)
Washington, DC -
Authors:
- Powers, T C
- Publication Date: 1966
Media Info
- Media Type: Print
- Pagination: pp 3-8
- Monograph Title: Symposium on structure of Portland cement paste and concrete
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Serial:
- Highway Research Board Special Report
- Issue Number: 90
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Calorimeters; Concrete; Electron microscopes; Laboratories; Measurement; Numbers; Physical properties; Research; Rheological properties; Sorption; Stereoscopic cameras; Structures; Urban growth; X rays
- Identifier Terms: Portland Cement Association
- Uncontrolled Terms: Concrete properties
- Old TRIS Terms: Brunauer emmett teller method; Photomicrographs; Stereoscopic photography
- Subject Areas: Bridges and other structures; Highways; Materials; Research;
Filing Info
- Accession Number: 00212307
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Nov 18 1994 12:00AM