Determination of Creep Compliance and Tensile Strength of Hot-Mix ...

Table 14: Instrumented Tensile Strength: -10°CMix ID No. Replicates Average Air Voids (%) S t (psi) SD (psi) CV (%)07-123 3 6.8 594* 59.6 10.006-105 3 6.5 571 35.2 6.206-84 3 4.1 697 19.2 2.806-84 3 6.5 618 46.7 7.606-84 3 9.0 551 58.0 10.506-101 3 4.0 773 15.4 2.006-101 3 6.5 625* 39.7 6.406-101 3 9.0 573 15.2 2.606-125 3 4.0 587* 36.1 6.106-125 3 6.5 509* 108.8 21.406-125 3 9.0 484* 37.1 7.706-150 3 4.0 780* 47.5 6.106-150 3 6.6 630* 20.0 3.206-150 3 9.0 550* 15.8 2.9*Based on one or more instances of a maximum y-x differential occurring prior to themaximum load being reachedOf the instrumented IDT strength testing at three different temperatures, “first failure”as a result of maximum y-x differentials occurring prior to obtaining the maximumload was present only during the testing at -10°C. Of the 42 specimens representedin Table 14, 11 “failed” prior to the maximum load being reached. The amount oftime that transpired between the maximum y-x differential and the maximum loadranged from 0.1 to 0.6 seconds. It should be noted that a data acquisition rate of ~20Hz was depicted in the M-E PDG Appendix HH when describing the “first failure” dueto a maximum y-x differential phenomenon. Therefore, while the data acquisitionrate of 10 Hz as specified in T 322-07 for creep testing was used in this study, moreaccurate determinations of “first failure” may have been possible at higheracquisition rates.31