Adeleke A.A., Adeosun A.S., Disu A.O., Olorunniwo E.O.
Department of Materials Science and Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria
Adeleke, A.A., Department of Materials Science and Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria; Adeosun, A.S., Department of Materials Science and Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria; Disu, A.O., Department of Materials Science and Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria; Olorunniwo, E.O., Department of Materials Science and Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria
The suitability or otherwise of the abundant Nigerian Ondo bitumen as a binder in hot mix asphalt concrete mix design for roadmaking has not been established. Samples of Ondo bitumen (as-received and as-refined) were tested for specific gravity, softening point and penetration. Concrete mixes were also prepared with standard proportions of aggregates with Ondo bitumen (as-received and as-refined) and standard bitumen as binders. The concrete mixes were then compacted to standard cylindrical specimens for Marshall stability indices tests. The results of physico-chemical tests gave the specific gravity, softening point and penetration for the Ondo bitumen as-received as 1.12, 77°C and 44.3 mm, while the values for the refined product were 1.03, 52°C and 67 mm, respectively. The Marshall stability tests for Ondo bitumen (as-received) at 5.8% of the weight of aggregate yielded 25.5 KN, 15 mm, 77.4%, while that of Ondo bitumen as-refined gave 13.03 KN, 35 mm, 77.4%; respectively. When the physico-chemical properties Ondo bitumen (as-received and asrefined) were compared with those of standard bitumen, only the refined product was found to satisfy the requirements for concrete mix design. The Marshall stability results however showed that Ondo bitumen concrete mixes (as-received and as-refined) do not meet the standard specifications for stability and flow. The results obtained thus suggest that Ondo bitumen may not be useable alone for direct asphalt mix design.