TOPICS IN CONCRETE TECHNOLOGY-CHARACTERISTICS OF AIR-VOID SYSTEMS
ENTRAINED AIR MUST BE DISTRIBUTED THROUGH THE PASTE AS SMALL BUBBLES; TO SERVE ITS PRINCIPAL PURPOSES, THE NUMBER OF BUBBLES PER UNIT VOLUME OF AIR OR MEAN BUBBLE SIZE IS A PRE-EMINENT CHARACTERISTICS. AT PRESENT, SPECIFIC SURFACE AREA, (55%) IS THE MOST USEFUL FUNCTION OF MEAN BUBBLE SIZE. DETREMINANTS OF 55A IN NEAT PASTE ARE: KIND AND DOSAGE OF AIR-ENTRAINING AGENT, DURATION OF STIRRING, STIRRER SPEED (SHEAR STRESS), AND PASTE VISCOSITY. BUBBLE SIZE DISTRIBUTION IS INDICATED APPROXIMATELY BY: A SPACING FACTOR COMPUTED FROM 55A PASTE CONTENT, AND AIR CONTENT. /PCA/
-
Authors:
- Powers, T C
- Publication Date: 0
Media Info
-
Serial:
- Portland Cement Assoc R & D Lab Bull
- Issue Number: 0
Subject/Index Terms
- TRT Terms: Air content; Air entraining agents; Air voids; Bubbles; Entrained air; Mixing; Pastes; Shear stress; Spacing; Specific surface; Surfaces; Viscosity
- Uncontrolled Terms: Surface area
- Old TRIS Terms: Air voids content; Stirring
- Subject Areas: Highways; Materials;
Filing Info
- Accession Number: 00213615
- Record Type: Publication
- Source Agency: Portland Cement Association
- Report/Paper Numbers: No 174
- Files: TRIS
- Created Date: Jun 1 1970 12:00AM