Study of LTPP laboratory resilient modulus test data and response characteristics.

Details

• Creators:
  Yau, Amber ; Von Quintus, Harold L.
• Corporate Creators:
  Fugro-BRE, Inc. ; United States. Department of Transportation. Federal Highway Administration. Office of Infrastructure Research and Development
• Subject/TRT Terms:
  • Flexible pavements
  • Asphalt concrete pavements
  • Modulus of resilience
  • Asphalt tests
  • Testing equipment
  • Test procedures
  • Flexural strength
  • Pavement components
  • Load tests
  • Cone penetrometers
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• Publication/ Report Number:
  FHWA-RD-02-051;3032.1
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States
• Edition:
  Final report; June 2000-Oct. 2001
• Corporate Publisher:
  Turner-Fairbank Highway Research Center
• Abstract:
  The resilient modulus of every unbound structural layer of the Long Term Pavement Performance (LTPP) Specific Pavement and ; General Pavement Studies Test Sections is being measured in the laboratory using LTPP test protocol P46. A total of 2,014 ; resilient modulus tests have passed all quality control checks and are included in the LTPP database with a Level E data status. As ; of October 2000, there were 1,639 resilient modulus tests yet to be performed. In some cases, these missing tests may have been ; performed, but did not achieve a Level E status (did not pass all quality control checks) in the LTPP database. However, these test ; results have not been evaluated in detail. This report documents the first comprehensive review and evaluation of the resilient ; modulus test data measured on pavement materials and soils recovered from the LTPP test sections. ; The resilient modulus data were reviewed in detail to identify anomalies or potential errors in the database. From this review, a ; total of 185 resilient modulus tests were identified with possible problems or data entry errors. These tests were reported to ; FHWA for further review andlor retesting. The resilient modulus test data were found generally to be in excellent condition with ; less than 10 percent of the tests exhibiting potential anomalies or discrepancies in the data. ; The resilient modulus test data were then studied for the effect of test variables, such as the test and sampling procedures, on the ; resulting resilient moduli. These data were analyzed by material code for the base and subbase aggregate layers and by soil type ; for the subgrade. Sampling technique (auger versus test pit) was found to have the most effect on the crushed stone aggregate ELlid ; uncrushed gravel base materials. For the subgrade soils, sampling technique (Shelby tubes versus auger samples) had the most ; effect on the clay soils. Sampling technique was found to have little to no effect on the sand basehubbase materials and sand soils. ; The resilient modulus data were further investigated to evaluate relationships between resilient modulus and the physical ; properties of the unbound materials and soils. Using nonlinear regression optimization techniques, equations for each base and ; soil type were developed to calculate the resilient modulus at a specific stress state from physical properties of the base materials ; and soils. The primary result from these studies is that the resilient modulus can be reasonably predicted from the physical ; properties included in the LTPP database, but there is a bias present in the calculated values. Thus, until additional test results ; become available to improve or confirm these relationships, it is recommended that at least some laboratory tests be performed to ; measure the resilient modulus for unbound pavement materials and soils.
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• Format:
  PDF
• Funding:
  DTFH61-95-C-00028
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/25305/dot_25305_DS1.pdf
• File Type:
  [PDF - 11.00 MB]
• Collection(s):
  US Transportation Collection ; Federal Highway Administration
• Main Document Checksum:
  urn:sha-512:08d43d0da302f64718ad7c91f637337da22cbb5664316079d0f7c1dfa0cd92ba55c1390f2232641ce4fcee0e189217ce41399be7fe43e85e1485e87a62712025