FTIR-BASED CHEMICAL INTERACTION STUDY OF RICE HUSK ASH MODIFIED AGBABU NATURAL BITUMEN

Abstract

Bitumen is a mixture of hydrocarbons widely used as a binder in road pavements but has certain limitations, including oxidative failure and various surface defects. These challenges led to the modification of Agbabu Natural Bitumen (ANB) using rice husk ash (RHA), with the expected result that it might mitigate the adverse effects of conventional bitumen. The raw ANB was modified in a stainless reactor using the rice husk ash at five different proportions maintaining a temperature of 100-110 ̊C. The modified bitumen was analyzed using Fourier Transform Infrared (FTIR) spectroscopy. The carbonyl peaks are reduced to 1701cm^-1 while the aliphatic contents are retained both in the raw and modified ANB and the aromatics and sulfoxide peaks are stable.  The peaks at 3448.84cm^-1, 2854.74 cm^-1, 1716.7cm^-1, 1608.69cm^-1, 1377.22cm^-1, 1033.88cm^-1corresponds to O-H stretching of alcohol, C-H stretching of alkane, C=O stretching of carbonyls, C=C stretching of aromatics rings, C-H bending of methyl groups and S=O stretching of sulfoxide respectively.  The silicates peaks were also observed at 420.5cm^-1, 466.79cm^-1, 570.95cm^-1, and 582.52cm^-1. The interaction of ANB with RHA showed that the silicate components present in RHA can serve as potential antioxidants for improving the performance of ANB in pavements.