The influence of rice bran oil and nano-calcium oxide into bitumen as sustainable modifiers
Mahyar Arabani, Mostafa Sadeghnejad, Javad Haghanipour, Mohammad Hossein Hassanjani
Abstract
Bio-oils are increasingly used to enhance petroleum bitumen’s intermediate and low-temperature characteristics regarding their economic and environmental benefits. Research has shown a beneficial impact of nanomaterials on altering bitumen’s high-temperature characteristics. The present study uses a mixture of rice bran oil and nano-calcium oxide to improve the performance of bitumen in all three temperature conditions. Rice bran oil was added to pure bitumen at doses of 3, 5, and 7 % relative to the weight of bitumen. The rheological tests (dynamic shear rheometer , multiple stress creep recovery, linear amplitude sweep, and bending beam rheometer) demonstrated that using rice bran oil in bitumen enhanced its performance at intermediate and low-temperatures but declined its performance at high-temperatures. Therefore, to improve the performance at high-temperatures, the bituminous sample containing 5 % rice bran oil was combined with 1, 3, and 5 % nano-calcium oxide, followed by repeating the rheological tests on them. The samples modified with nano-calcium oxide showed increased friction and shear stress, viscosity , and rutting parameters. Besides, the samples exhibited reduced sensitivity to aging compared to the bio-oil samples. However, the non-recoverable creep compliance and percentage of recovery showed improvements. The fatigue life of bio-oil samples decreased after adding nano-calcium oxide. However, the fatigue life remained higher than the base bitumen sample when adding 1 % nano-calcium oxide. Fourier-transform infrared spectroscopy analysis showed that a new chemical reaction occurred due to adding nano-calcium oxide to bitumen containing rice bran oil. Besides, the scanning electron microscope image revealed that the nano-calcium oxide particles are uniformly and homogeneously distributed within the bitumen sample containing 5 % rice bran oil. Consequently, the mix containing 5 % rice bran oil and 3 % nano-calcium oxide increases the resistance against high-temperature failures and improves the low-temperature performance compared to the base bitumen sample.