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:
  Anisotropy (Physics) Compression Tests Compressive Strength Concrete Concrete Pavements Cores (Specimens) High-strength Concrete In-place Strength Length-to-diameter Ratio
• 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.
  
  
• Format:
  PDF
• Funding:
  ALDOT Project 930-828
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:b5b772cee9b8debb4ce341e0551a4b607bcec8dac8a0ea1436181cf18ccbeb0b
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/32194/dot_32194_DS1.pdf
• File Type:
  [PDF - 4.46 MB ]