COMPRESSION TESTING OF CONCRETE: CYLINDERS VS. CUBES

Concrete cylinder and cube specimens for compression testing were compared through a survey of past research, including testing procedures, factors affecting the cylinder/cube strength ratio, and conversion factors and equations. The main difference between cylinder and cube testing procedures is capping. Cylinder ends are usually not plane or parallel enough to mate properly with platens of compression testing machines, and thus must be capped with sulphur, neoprene, or other suitable material for proper distribution of the applied load. Cubes, however, are not capped but cast in rigid molds with sides that are plane and parallel. When tested, they are flipped on their sides so that machine platens mate properly with cube surfaces. Factors affecting the cylinder/cube strength ratio are 1) casting, curing, and testing procedure; 2) specimen geometry; 3) level of strength; 4) direction of loading and machine characteristics; and 5) aggregate grading. Past efforts to determine empirical conversion relationships and conversion factors have shown that it is difficult (if not impossible) to predict relationships between cylinder and cube strengths. Past research has also shown the cylinder/cube strength ratio to be between about 0.65 and 0.90, although ratios outside that range have also been observed. Based on this survey of past research, replacing cylinder testing with cube testing is not recommended.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 28 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00760567
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/NY/SR-95/119
  • Files: NTL, TRIS, USDOT, STATEDOT
  • Created Date: Mar 26 1999 12:00AM