Evaluation of the Combined Effects of Hallow Concrete Block Waste and Recycled Asphalt Pavement for Using in Road Pavement Sub- base Course

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.