Volume 40, Issue 7 (December 2012)
A New “Mix-confined” Repeated Load Test for Evaluating Permanent Deformation of Asphalt Mixture
Existing tests for evaluating the permanent deformation of an asphalt mixture have many problems, such as the fixed confining pressure for repeated load triaxial tests (RLTTs). The main objectives of this paper are to develop a new “mix-confined” test and to compare the accuracy and sensitivity of this test with those of RLTTs. A new mix-confined repeated load test (MCRLT) is developed to measure the permanent deformation of two types of test specimens, including field cores extracted from asphalt pavement and lab-mixed specimens. The accuracy and sensitivity of the MCRLT are compared with those of an RLTT. The results show that during the MCRLT the test specimen can provide some (but not enough) confining pressure itself (so-called mix-confined). MCRLTs have slightly higher accuracy and lower sensitivity than RLTTs. The MCRLT can be a good alternative to the RLTT for evaluating the permanent deformation of asphalt mixtures, especially when there is no RLTT equipment available.