Study on the anti-aging properties of organic attapulgite (OATT) and polyurethane (PU) composite-modified asphalt

Abstract

Effects of organic attapulgite (OATT) and polyurethane (PU) on the anti-aging properties of OATT/PU composite-modified asphalt were investigated in this study. Firstly, the basic physical properties, high- and low-temperature rheological properties of OATT/PU composite-modified asphalt before and after aging were studied. Meanwhile, several aging indexes were calculated to quantify the anti-aging performance. In addition, Fourier transform infrared spectroscopy (FTIR) and atomic force microscope (AFM) were used to explore the modification mechanism and micro-morphology. The results indicated that the high-temperature properties of different asphalts were enhanced and the low-temperature properties were adversely affected by aging. As for the OATT/PU composite-modified asphalts, OATT and PU have always shown good synergistic effects in improving the high- and low- temperature properties of modified asphalts during aging. The anti-aging properties of asphalt were improved after the addition of OATT together with PU. OATT plays a significant role in improving the anti-aging performance of modified asphalt. OATT/PU composite-modified asphalt containing 2 wt% OATT showed the best anti-aging performance. The PU content in the composite modified asphalt was recommended to be 5 wt%, so as to obtain satisfactory anti-aging performance.