Abstract
Recycled asphalt pavement (RAP) is beneficial for conservation of natural resources as well as pavement construction
sustainability over time due to lower energy. Europe and North American authorities have developed protocols that govern
the recovery and use of RAP as secondary aggregate. Evaluation of RAP at different percentages of application in asphalt
pavement construction is important hence this research aims at evaluating the engineer ing characteristics of RAP as binder
course material. RAP 1 and RAP 2 were obtained from two sources, characterization of bitumen in the RAP and grading were
carried out and compare with specification. Binder course with blends of 10, 30, 50, 75 % RAPs and 100% virgin aggregates
serves as the control were design using relevant standards. Binder course-RAP blends were evaluated using Marshall test
(voids in total mix-VTM), Indirect Tensile Strength (ITS) and moisture sensitivity test (ITSR). The residual bitumen content for
RAP 1 and RAP 2 were 5.7 and 4.4 % respectively but the grading did not meet the required specification. The VTM of RAP
1(3.83-7.17 %) shows that the result obtained for the different percentages were higher than the control mix (3.79 %) while
RAP 2 (2.89-3.75 %) was lower and were within the range specified. The RAP 1 and RAP 2 at 50 % each exceed 100 %
showing little effects of water conditioning process in the binder course -RAP blends produced. The evaluation of the
properties of the blends of binder course with RAP 1 and RAP 2 shows that it is possible to use more than 50 % RAP content
in the mix preparation

Key words: Recycled asphalt pavement, binder course, indirect tensile strength, Marshall test, voids in total mix.