Laboratory investigation on the brucite fiber reinforced asphalt binder and asphalt concrete

Abstract

To investigate the modification of brucite fiber, fiber reinforced asphalt binder and asphalt mixtures were prepared and tested. Lignin fiber, basalt fiber and polyester fiber were used for comparative studies. Water absorption, oven heating, mesh-basket draindown were designed to evaluate the fiber wettability, thermostability, asphalt absorption and stabilization. Cone penetration test and dynamic shear rheometer test were applied to research the shear resistance rheological property and rutting resistance of fiber reinforced asphalt. In addition, the microstructure of fibers and reinforced asphalt binders were analyzed via scanning electron microscopy. Moreover, the engineering properties, containing high temperature stability, low temperature cracking resistance and moisture susceptibility, were conducted. Results show that brucite fiber has a better state of preservation in humid environment and thermostability than lignin fiber. It obtains a better effect on asphalt absorption and stabilization than basalt fiber and polyester fiber. Besides, the brucite fiber can effectively improve the rutting resistance and shear prevention of asphalt binders. The brucite fiber obtains a spatial networking to enhance the adhesion and stabilization of asphalt binders. The results also indicate that the asphalt mixture mixed with brucite fiber shows great high temperature stability, low temperature cracking resistance and moisture susceptibility.