Jordan Journal of Civil Engineering

Factors Influencing the Rheological Characteristics of Modified Corn Stalk Fiber Asphalt Mortar

Authors:

Kun Wang; Lu Qu; Zongwen Hu; Peng Hu; Hao Xu Hao Xu;

Abstract:

As the demand for sustainable and environmentally friendly road construction materials increases,Corn stalk fiber modified with NaOH is a promising candidate due to its renewable and eco-friendly nature.In this study, the effects of length, content and modifier concentration of modified corn stalk fiber on the rheological properties of asphalt mortar at high and low temperatures were studied by dynamic shear rheology (DSR) and bending beam rheology ( BBR ) tests using orthogonal experimental design.The bonding between fiber and asphalt was analyzed by infrared spectroscopy, and the action mechanism of fiber in asphalt was revealed from a microscopic perspective by scanning electron microscopy and fluorescence microscopy.Evidently,the concentration of modifier is the main factor affecting the rheological properties of fiber asphalt mortar.The best performance was obtained at a modifier concentration of 7%, a fibre length of 6 mm and a dosage of 1.5%. After adding modified corn stalk fiber, the asphalt mortar did not produce new characteristic peaks, and the fiber and asphalt were mainly bonded by physical action. The large surface roughness of the modified corn stalk fiber determines its good adsorption capacity, which is conducive to increasing the bonding force of the asphalt. Fibers with a large aspect ratio are easy to bridge with each other, restraining the expansion of cracks and thus enhancing the crack resistance of the mortar.

Keywords:

Road engineering, Corn stalk fiber, Asphalt mortar, Orthogonal test, Rheological properties