Authors:Ibrahim T. Yusuf and Yinusa A. Jimoh
Freeways (rural roads) are transportation facilities for movement of goods and people in trucks, automobiles and buses at desirable speeds in the country side between cities, towns and suburbs.
The intensity (frequency) and loads (often overloaded in magnitude) on these roads necessitate the provision of high strength pavement structure with zero and/or low maintenance needs especially
in areas substantially characterized with weak and poor subgrades, which are loose and/or settlement prone. This paper presents the rationalization of palm kernel shell wastes as coarse aggregates
for the provision of rigid pavements that are environmental friendly, structural efficient and cost effective freeways in the rural and coastal areas where aggregates are in short supply and palm
kernel waste dumps abound with consequential disposal and environmental pollution challenges. The appropriateness of the various nominal mixes of the ‘palm kernel shell concrete’ as
rigid pavement was evaluated accordingly at both fresh and matured ages with corresponding costs. The Nigerian palm kernel shell satisfies the density criterion for normal concrete and lightweight
concrete in all respects while the palm kernel shell concrete at nominal mixes of 1:11/2:3 and 1:1:2 satisfies the specifications for rigid pavement. In addition, the cost of producing PKS concrete/m2
for all levels of traffic and mix proportions is cheaper than those of normal concrete and asphaltic concrete. It was, therefore, recommended as a strategic and way forward of producing environmentally,
healthy, structural and cost effective pavement for transportation of goods on freeways.
Keyword:Palm kernel shell, rigid pavement, freeways, cost model, lightweight