The objective of the research was to determine the deformation characteristics of base material produced from recycled asphalt pavement (RAP) and aggregate. Cyclic triaxial tests were conducted at two deviator stresses, 35% and 50% of the estimated failure stress, to evaluate recoverable and permanent deformation behavior from initial loading to 5000 cycles. The specimens with RAP exhibited up to four times greater permanent deformation than the 100% aggregate material, and a steady state condition was reachedafter approximately 1000 cycles. This valuable information regarding thepermanent deformation is not collected during a resilient modulus (MR) test, because the first 1000 cycles are used for conditioning only. As %RAPincreased, more permanent deformation occurred. YoungÆs modulus (Esecant), which was computed in the same manner as MR, increased as the number ofcycles increased. Initially, Esecant was larger for the 100% aggregate specimens, but after approximately 100 cycles the 25% aggregateû 75% RAP specimens had the highest Esecant. The cyclic tests at the 50% stress ratioexhibited greater permanent deformation by a factor of 2û 3 compared to the 35% stress ratio tests, and Esecant was about 15% greater at the higherdeviator stress.
Abstract