Skip to main content

NCHRP Web Doc 14 Laboratory Determination of Resilient Modulus for Flexible Pavement Design Final Report (1997) / Chapter Skim
Currently Skimming:

5 Summary, Conclusions and General Recommendations
Pages 278-285

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 278...
... Use a fully automated testing system for routine resilient modulus testing or extensive research applications. A complete, automated testing/data acquisition/data reduction system is necessary to achieve reliable resilient modulus test results, especially when conducted as a routine test by a technician.
Read the entire page →
From page 279...
... Proof testing using synthetic specimens also serves to train laboratory technicians. Human Related Problems The laboratory validation study clearly showed several considerations to be important in resilient modulus testing.
Read the entire page →
From page 280...
... Mountable deformation measurement devices are recommended for resilient modulus testing because of the smaller variability. The SHRP EG device minimizes rocking of the specimen.
Read the entire page →
From page 281...
... The usually used loading time of 0. ~ sec., represents slow traffic conditions that cause significant damage to the pavement and should be continued to be used for resilient modulus testing.
Read the entire page →
From page 282...
... BASE AND SUBGRADE RESILIENT MODULUS TESTING METHODS AND PROCEDURES The repeated load biaxial test is recommended to evaluate the resilient modulus of base, subbase and granular subgrade materials. A repeated load test performed on an unconfined specimen is recommended for cohesive subgrade soils.
Read the entire page →
From page 283...
... (3) The resilient modulus does not properly depict permanent deformation characteristics of the subgrade which should be evaluated by the repeated load biaxial test using an appropriate stress state.
Read the entire page →
From page 284...
... Not an easy task unless the test is fully automated Requires a significant amount of time and is subject to testing errors Requires equipment that is relatively expensive May not be production oriented depending upon the available equipment A very attractive approach for obtaining resilient moduli for use in design, for at least most agencies, is to determine values of resilient modulus using generalized empirical relationships. Such relationships give resilient modulus as a function of statistically relevant, easy to measure physical properties of He material such as percent compaction, water content, etc.
Read the entire page →
From page 285...
... SUGGESTED ADDITIONAL RESEARCH The following research topics are considered to be important in determ resilient moduli for design and deserve additional research: . fining reliable, practical I. Develop generalized relationships between resilient modulus and easy to measure material parameters for asphalt concrete, granular base and subgrade soils and cohesive subgrade materials.
Read the entire page →

Key Terms

  • resilient moduli
  • modulus testing
  • modulus test
  • repeated load
  • axial deformation

  • asphalt concrete
  • synthetic specimens
  • permanent deformation
  • cohesive subgrade
  • data acquisition

  • modulus relationships
  • subgrade materials
  • load biaxial
  • measured resilient
  • subgrade soils

  • biaxial test
  • significant difference
  • deformation characteristics
  • load test
  • deformation measurements

  • develop generalized
  • deformation measurement
  • mountable extensometer
  • compacted cohesive
  • generalized resilient

  • testing methods
  • specimen aging
  • load pulse
  • modulus decreases
  • using synthetic


    • This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
    More information on Chapter Skim is available.