Abstract:
Road network is the prime mover for the development of every country. In Ethiopia, the
capital investment for the network development is increasing to meet its medium and long
term development plan. To expand the road network, the construction materials are the
perennial main issues because of the availability of virgin materials which is very limited,
and their costs are becoming high. To lessen such impact of the problem, used of
recycled materials with low cost and environmentally friendly could be the alternative
approach. Unfortunately, using Reclaimed asphalt pavement (RAP) and waste HCB had
not been fully recognized in Ethiopia despite the current ambitions of road-building
programs in the country. However, RAP and waste HCB materials may not be
conventional road-making materials as compared with the other materials, of which
requires further study. This study focused to evaluate the Combined Effects of Waste
Hollow Concrete Block (HCB) and Recycled Asphalt Pavement for used in Road
Pavement Sub-base Course. The Reclaimed Asphalt Pavement (RAP) was taken from
road from Hana Mariam to garment, while the waste HCB was taken from Legehare
which shipping and logistic building was demolished. In this study, the waste HCB and
RAP were blended in their natural state in the laboratory and determined the mechanical
and physical properties, and compared with the Standard Specifications. The proportions
considered waste HCB and RAP with 100/0, 80/20, 70/30, 60/40, 50/50, 0/100 by total
weights in percent. Laboratory test results indicated, the ACV, AIV, LAA, SG, Water
absorption , CBR and FI 0f 5.63 to 20, 5.9 to 24.2,8.5.%to30.35% ,1.88 to 2.6, and
0.371to13.9% 22.5 to 78.3%, 14.16 to 16.4 respectively. Further laboratory tests
conducted by blending of 30% RAP and 70% waste HCB showed a test results of 16.87%
ACV, 17.1 AIV, 29% LAA, SG of 2.6, 0.85% water absorption, and a CBR value of
40%.Hence, these results indicated that meet with the ERA,BS,AASHTO, Standard
Specifications. 30% RAP and 70% waste HCB could be used for sub-base course in road
pavement construction recommended.
