EVALUATION OF STRENGTH TESTS AND ACCEPTANCE OF CONCRETE PAVEMENTS. PROCEEDINGS, 4TH INTERNATIONAL CONFERENCE ON CONCRETE PAVEMENT DESIGN AND REHABILITATION, PURDUE UNIVERSITY, APRIL 18-20, 1989

One of the most troublesome phases of a concrete pavement construction project can be the determination of whether the strength of the concrete meets the project specifications. This determination can be complicated by the fact that the flexural strength test is often the test specified for acceptance and there is often little or no understanding of the procedures and precision of the flexural strength test. The quick placement of large volumes of concrete for pavement construction projects means that a million dollars or more worth of concrete can be "on the ground" before the first acceptance test is ever performed. If questions arise regarding the validity of the acceptance tests, then a good understanding of the variations inherent in the flexural strength test are necessary for a proper evaluation of the acceptability of the concrete. The results of analyses to determine the statistical parameters for flexural strength test results for more than one million cubic yards of concrete pavement constructed at the Atlanta International Airport are presented in this paper. Parameters for within-test statistical variations are presented so that the quality of the testing agency personnel can be evaluated. Parameters for the between-test statistical variations are presented so that the quality of production by the contractor can be evaluated. The results of the analyses indicate that the within-test variations can approach the between-test variations and this greatly contributes to the confusion and misunderstandings. The analyses also show that two flexural strength test results from the same batch of concrete can be expected to vary by as much as 100 psi and not be considered suspect 95% of the time. The difference between the average flexural strengths of each of two batches of the same concrete mix in the laboratory can differ by as much as 75 psi and not be considered suspect 95% of the time. Procedures for adjusting the actual flexural strength test results upward based on additional thickness over the design thickness or downward based on deficient thickness from the design thickness are given.

• Corporate Authors:

  Purdue University

  School of Civil Engineering, 550 Stadium Mall Drive
  West Lafeyette, IN  United States  47907

  Federal Highway Administration

  Turner-Fairbank Highway Research Center, 6300 Georgetown Pike
  McLean, VA  United States  22101
• Authors:
  • Greer Jr, W C
• Publication Date: 1989-4

Media Info

• Features: Figures; References;
• Pagination: p. 375-383
• Serial:
  • Publication of: Purdue University
  • Publisher: Purdue University

Subject/Index Terms

• TRT Terms: Acceptance tests; Airport runways; Concrete; Concrete pavements; Flexural strength; Pavement design; Specifications; Statistical quality control; Strength of materials; Thickness; Variables
• Uncontrolled Terms: Concrete strength
• Old TRIS Terms: Aprons; Test results; Thickness design; Variations
• Subject Areas: Design; Highways; Pavements; I22: Design of Pavements, Railways and Guideways;

Filing Info

• Accession Number: 00486351
• Record Type: Publication
• Report/Paper Numbers: FHWA-RD-89-208, 3C1B1144
• Contract Numbers: DTFH61-87-C-00140
• Files: TRIS, USDOT
• Created Date: Aug 31 1989 12:00AM