Synthesis and characterization of asphalt composite precursors using amorphous rice husk silica

Abstract

In this research, asphalt composites were produced by mixing asphalt with silica extracted from rice husk, with a ratio of asphalt to silica of 1:0, 1:1.7 and 1:2, and calcined at 150 °C. Development of structures was characterized using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), followed by differential thermal analysis (DTA/TGA). The FTIR results showed the presence of Si-OH, C=O, and C-H functional groups, which were associated with asphaltene, carbon, and silica, according to the XRD analysis. The results obtained also indicated the significant effect of rice husk silica addition on phase transformation of asphaltene into silica and carbon, while asphaltene molecules were practically undetected. The presence of silica and carbon resulted in increased decomposition temperature of the sample. Based on these characteristics, the samples were considered as a roof material, suggesting their potential use as a substitute for lightweight steel roof devices.