Cracking Resistance of Cold Bitumen Emulsion Mix Containing Different Fillers

Despite being economically and environmentally friendly, the use of cold bitumen emulsion mix (CBEM) is still limited to minor repair work and construction of low volume roads. One of the reasons behind this underutilization is its poor cracking resistance. Fillers have significant effects on the cracking resistance of asphalt mixes. So, the present study aims at examining the effect of different fillers, i.e., stone dust, cement, lime, fly ash (FA), and ground granulated blast furnace slag (GGBFS) on the cracking resistance of CBEM. The cracking resistance of CBEM was examined by indirect tensile strength (ITS) and semicircular bending (SCB) tests. Results showed that the inclusion of active as well as waste fillers significantly improved the cracking resistance of all modified CBEM. However, the cracking resistance developed by FA and GGBFS modified CBEM were not comparable to cement modified CBEM. So for further modification, lime was added to FA and GGBFS modified CBEM, which further enhanced the cracking resistance of CBEM, making it comparable to that of cement modified CBEM. This experimental study was further extended to examine the effect of these fillers on the properties of cold bitumen emulsion mastic (CBEMa) by conducting scanning electron microscopy (SEM), X-ray diffraction (XRD), and linear amplitude sweep (LAS) tests. The SEM and XRD results confirms the presence of hydration products in the mastic phase of CBEM. In addition, a Pearson correlation analysis was carried out between the LAS parameters of CBEMa and the cracking resistance parameters of CBEM, confirming a linear association between both characteristics.