Enhancing Durability of Submerged Flexible Pavement Surfacing Using Cassava Peel Ash as Void Filler (Heavy Traffic)

Abstract

The need to reduce expenses associated with traditional materials for pavement construction has made the exploration of alternative materials often considered waste as exceptionally important. These alternatives have the possibility to improve the structural integrity of the pavement. One such material is cassava peel; an agricultural by-product commonly found in the Niger Delta region of Nigeria. When processed into a pulverized form, cassava peel ash (CPA) may yield satisfactory results in pavement construction. The study aims to investigate the impact of CPA on the stability and swelling characteristics of submerged asphalt concrete designed for heavy traffic applications. An experimental method was employed, incorporating CPA into the asphalt concrete mixture at varying concentrations of 0%, 2.5%, 5.0%, 7.5%, and 10.0%, guided by the principles of the Marshall Mix design. Specimens were subjected to moisture submersion for periods ranging from 1 to 5 days. The results indicate that the optimal performance was achieved with a 7.5% concentration of CPA, showing an enhanced stability of 49.89% when un-submerged. This increased to 56.25% after 1 day of immersion, 64.86% after 2 days, 64.51% after 3 days, 66.85% after 4 days, and 65.55% after 5 days. Additionally, the loss of stability was reduced by 4.24% after 1 day of immersion, 9.99% after 2 days, 9.76% after 3 days, 11.31% after 4 days, and 10.45% after 5 days. The swelling was also minimized, showing a reduction of 23.09% after 1 day, 28.08% after 2 days, 22.54% after 3 days, 25.89% after 4 days, and 28.97% after 5 days of immersion. These improvements ultimately contribute to the durability of the pavement under submerged conditions.