An Experimental Study on the Properties of β-Keratin as Dust Suppressant for Gravel Roads

This study aimed to investigate the suitability of β-keratin, produced from chicken feathers, as a surface sealant to suppress dust on gravel roads, in terms of mechanical, chemical, and physical properties. This study used High-Performance Thin Layer Chromatography (HPTLC) chemical tests, Ultraviolet-Visible Spectrometer (UV-ViS) physical tests, and the standard testing procedures of the American Society for Material Testing (ASTM) and American Association of Highway and Transportation Officials (AASHTO) for mechanical tests. For testing its mechanical properties, β -keratin was mixed with gravel at 0, 1.5, 2.0, 2.5, and 3.0% proportions of dry weight. The wavelength and absorbance of a β-keratin water solution (1:10) were 275.4nm and 0.4295 respectively. β -keratin is a hydrocarbon with the chemical formula C28H48N2O32S4 and easily melts and burns under fire. 1 liter of Keratin mixed with the carboxymethyl cellulose (CMC) emulsifier at 55 and 65g/liter yielded acceptable results between 30-60kg/m·s viscosity at 60°C according to ASTM D2170 and AASHTO T201. The optimal percentage mix of β-keratin in the gravel mixture was found to be 2.0%, providing a CBR value of 57%, least swell of 0.3%, MDD of 1850kg/m3, and OMC of 15.8%, all acceptable according to BS 1377:2-1990. For better dust suppressant results, 1 liter of pure β-keratin should be mixed with 55-65g of CMC.