Effect of core geometry and size on concrete compressive strength.

Details

• Creators:
  Carroll, Adam C. ; Grubbs, Aaron R. ; Schindler, Anton K. ; Barnes, Robert W.
• Corporate Creators:
  Auburn University. Highway Research Center
• Corporate Contributors:
  Alabama. Department of Transportation
• Subject/TRT Terms:
  • Compressive strength
  • Compression tests
  • Concrete
  • Anisotropy (Physics)
  • Cores (Specimens)
  • Concrete pavements
  • High-strength concrete
  • length-to-diameter ratio
  • in-place strength
• Publication/ Report Number:
  ALDOT 930-828-1
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States ; Alabama
• Corporate Publisher:
  Auburn University. Highway Research Center
• Abstract:
  To evaluate the in-place concrete strength for acceptance for a structural member with ; potentially substandard strength, the compressive strength of cores may be required for ; assessment. Depending on the geometry and size of the core specimen, the compressive test ; results may need adjustment to characterize the in-place concrete strength. The ; comprehensive experimental study performed examines core test results for factors including: ; three targeted strengths (6,000, 8,000, and 10,000 psi), two coarse aggregate sizes (No. 67 ; and 57), five core length-to-diameters (1.0, 1.25, 1.5, 1.75, and 2.0), two core diameter sizes (3 ; and 4 in.), and two coring directions (parallel and perpendicular). The data represent 390 core ; specimens obtained from 12 separate concrete castings. ; The data indicate that the core diameter significantly affects the strength correction factors ; for various length-to-diameters (l/d). For 4 in. diameter cores, only a slight difference from the ; currently recommended core l/d strength correction factors in AASHTO T 24 (2007) is ; observed. However, 3 in. diameter cores do not behave the same as 4 in. diameter cores when ; evaluated for core l/d effects on compressive strength. The analyzed data indicate that as the ; volume of the core specimen decreases, the compressive strength results become less ; reliable. Additionally, AASHTO T 24 (2007) recommends a core diameter of at least 3.75 ; inches. Based on the analysis, cores having a l/d less than 2.0, should not have a core ; diameter less than 3.75 inches. ; For cores having l/d of 2.0, the data indicate that the average strength of 3 in. diameter ; cores is 94 percent of the average strength of a 4 in. diameter core. Results also indicate the ; average strength of cores drilled perpendicular to the placement direction is 96 percent of the ; average strength of cores drilled parallel to the placement direction.
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• Format:
  PDF
• Funding:
  ALDOT Project 930-828
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/32194/dot_32194_DS1.pdf
• File Type:
  [PDF - 4.46 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:b5b772cee9b8debb4ce341e0551a4b607bcec8dac8a0ea1436181cf18ccbeb0b