THE AIR-ENTRAINED SYSTEM IN HARDENED CONCRETE-MICROSCOPIC MEASUREMENT AND INTERNATIONAL RING AND BALL TEST PROGRAMME

DAS LUFTPORENSYSTEM IN ERHAERTETEN BETON - MIKROSKOPISCHE AUSMESSUNG UND INTERNATIONALER RINGVERSUCH

Twenty testing institutes from nine countries participated in an international ring and ball test programme. Here it was shown that particularly "accurate" study methods with increases in scale reduce the distance factors over 50 times, with the result that appropriate air-entrained systems can no longer give a false impression of accuracy. Against this, unsuitable and inadequate grinding methods and careless measuring cause the concrete to appear worse than it actually is. By omitting compaction voids and counting only spherical voids, accuracy can be doubled in such a way that the Rosiwal test becomes just as accurate as the cube test of concrete. The distance factor calculated from the spherical voids only should amount to 0.22 mm at most. /TRRL/

• Authors:
  • SOMMER, H
• Publication Date: 1976

Language

• German

Media Info

• Features: Figures; Photos; References;
• Pagination: p. 67-72
• Serial:
  • Zement und Beton
  • Volume: 21
  • Issue Number: 2
  • Publisher: Verein de Oesterreich Zementfab & Oester Beton

Subject/Index Terms

• TRT Terms: Accuracy; Air entrained concrete; Errors; Microscopes; Microscopy; Porosity; Testing; Tests
• Uncontrolled Terms: Group analysis (Testing); Ring test
• ITRD Terms: 4742: Air entrained concrete; 6440: Error; 6219: Group analysis (test); 6790: Microscope; 5938: Porosity; 6255: Test
• Subject Areas: Highways; Materials; Planning and Forecasting; I32: Concrete; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 00159751
• Record Type: Publication
• Source Agency: Bundesanstalt für Straßenwesen (BASt)
• Report/Paper Numbers: Analytic
• Files: ITRD, TRIS
• Created Date: Dec 27 1977 12:00AM