Development and road performance of clear asphalt with high transparency and adhesion

Clear asphalt(CA)currently used in light-colored asphalt mixtures(LCAM)exhibits poor transparency and adhesion.Therefore,a highly transparent CA(HCA)modified using a silane coupling agent(KH550)was prepared.Furthermore,LCAM was prepared by mixing CA and limestone aggregates.The properties of the HCA and ordinary CA(OCA)were characterized using conventional asphalt tests,optical tests,pull-off tests,ultraviolet aging tests,dynamic shear rheometry,Fourier-transform infrared spectroscopy,differential scanning calorimetry,and scanning electron microscopy.Whereas Marshall,moisture resistance,wheel tracking,trabecular bending,and British pendulum tests were employed for the LCAM.The transmittance and spectral reflectance of the HCA were 123.30 and 3.74 times greater than those of the OCA,respectively.The complex modulus and viscosity-aging index of the HCA were 48%and 53%less than those of the OCA,respectively.After modification with KH550,the Marshall stability ratio,tensile strength ratio,and flexural strain of the HCA-prepared LCAM increased by 12.92%,25.06%,and 23.90%,respectively.However,the rutting resistance of the HCA-prepared LCAM was 14.3%less than that of the OCA-prepared LCAM.The comprehensive performances of the HCA and HCA-prepared LCAM were 49.2%and 10.3%greater than those of the OCA and OCA-prepared LCAM,respectively,indicating a high application value in the future.