摘要: |
The purpose of this paper is to describe the fabrication, calibration, and use of high-density polyethylene (HDPE) reference standards for the indirect tension (IDT) creep test, which was developed during the Strategic Highway Research Program and is one of the standard Superpave mixture tests now under further development and implementation. The use of reference standards in conjunction with the IDT test will help to achieve rapid and effective implementation of this promising test method. An IDT reference standard is useful in three ways: as a final step in a thorough calibration of the IDT system, for rapid verification of the IDT test system between calibrations, and as a tool for training engineers and technicians in proper execution of the test. In this study, HDPE specimens were calibrated using the IDT creep test. During this calibraiton, statistical methods were used to verify that the HDPE was homogenous, linear, and isotropic. The calibration was then confirmed using companion specimens of the HDPE machined for testing by using the bending beam rheometer (BBR). It was concluded that useful IDT reference standards can be machined of HDPE and that these specimens can be calibrated using repeated testing on the IDT, with further confidence provided through verification of the calibration using BBR specimens. Companion BBR specimens are also potentially useful for detecting any long-term changes in the properties of the HDPE reference standards. |