Published Online: 1 September 2012
Page Count: 8
Civil Engineer, Dynatest Engenharia Ltda., São Paulo, SP
Wisconsin Distinguished Professor, Dept. of Civil and Environmental Engineering, Univ. of Wisconsin-Madison, Madison, WI
Professor, Dept. of Civil and Environmental Engineering, Univ. of Wisconsin-Madison, Madison, WI
(Received 30 October 2011; accepted 4 June 2012)
The long-term pavement performance (LTPP) resilient modulus test protocol specifies the use of external linear variable differential transformers (LVDTs) to measure the material’s response, whereas the Mechanistic-Empirical Pavement Design Guide (MEPDG) requires input for resilient modulus based on the test results using internal LVDTs. Given this discrepancy of data, the relationship between resilient modulus determined from internal and external measurements was studied for a variety of materials using the NCHRP Project 1- 37A resilient modulus test protocol and recording deformation data both with internal and external LVDTs. Resilient moduli determined from internal deformation measurements shows to be higher than those from external measurements, whereas the ratio of external to internal resilient modulus decreases with increasing internal resilient modulus because of an increasing effect of machine compliance as specimens become stiffer. Furthermore, the relationship between internal and external resilient modulus depends on the material type.
Paper ID: GTJ20120077