Studies On Preparation And Characterization Of Flame Retarded Epoxy Road Materials

High-performance epoxy road materials have been widely used in the pavement on the steel plate deck and in tunnels. In the first part of thesis, the effects of asphalt on the properties of epoxies for preparing two kinds of domestic epoxy asphalt binders, i. e., warm-mix epoxy asphalt (WEA) and hot-mix epoxy asphalt (HEA) binders, were investigated. The cure behavior, viscosity, glass transition temperature (Tg), damping properties, thermal stability, mechanical properties and morphology of epoxy and epoxy asphalt binders were evaluated by rotational viscometer (RV), dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), universal test machine, and scanning electron microscopy (SEM). The RV results showed the addition of asphalt increased the viscosity of epoxy for WEA binder, WEP, but decreased the viscosity of epoxy for HEA binder, HEP, respectively, which suggested that asphalt accelerated the cure reaction of WEP and hindered the cure reaction of HEP. The addition of asphalt decreased the glass transition temperature (Tg) of WEP, while the Tg of HEP increased with the incorporation of asphalt. Furthermore, the Tg of WEA was lower than that of the HEA. The addition of asphalt improved the damping properties and thermal stability of WEP and HEP. In addition, HEA had better damping properties and thermal stability than WEA. The addition of asphalt increased the tensile strength and decreased the elongation at break of WEP, respectively. However, HEP showed the opposite trend. WEA and HEA had nearly the same tensile strength, but the elongation at break of WEA was much higher than that of HEA. The phase separation was observed in the cured epoxy asphalts, in which epoxy served as continuous phase and asphalt acted as disperse phase. Moreover, the particle size of asphalt in WEA was slightly larger than that of asphalt in HEA.Secondly, horizontal burning and limiting oxygen index (LOI) were conducted to evaluate the effects of mixed decabromodiphenyl ethane (DBDPE) and antimony trioxide (Sb2O3) on flame retardancy for warm-mix epoxy asphalt binder. The influence of DBDPE/Sb2O3 on the rotational viscosity, the thermal and mechanical properties of epoxy asphalt binder was evaluated by TGA, differential scanning calorimetry (DSC), and tensile test. The addition of DBDPE/Sb2O3 reduced the horizontal burning classification of epoxy asphalt binder from FH-2 to FH-1, and the LOI values of EAs was also significantly increased. The addition of flame retardants had no significant effect on the rotational viscosity of EA in the initial stage of cure reaction. TGA results showed that the presence of DBDPE/Sb2O3 improved the thermal stability of the epoxy asphalt binder. The addition of DBDPE/Sb2O3 had little effect on the tensile strength of the epoxy asphalt binder. However, the elongation at break of flame-retarded EAs was lower than that of the neat EA.Polymer mortar with excellent mechanical strength and durability has been widely used in road pavement and other construction industry. In last part of the thesis, two kinds of brucites, synthetic and natural brucites were incorporated in the epoxy mortar binders as flame retardants. The components, thermal stability and morphology of the two kinds of brucites were investigated by X-ray fluorescence (XRF), X-ray diffraction (XRD), TGA and SEM. The flame retardancy of brucite-modified epoxy mortar binders was evaluated by the horizontal burning and limiting oxygen index tests. The influence of flame retardants on the rotational viscosity, the thermal and mechanical properties of epoxy mortar binders was determined by RV, DSC, TGA, and universal test machine. Furthermore, the morphology of flame retarded-epoxy mortar binders was characterized by SEM. The addition of brucites significantly improved the flame retardancy, thermal stability and tensile strength of epoxy mortar binders. Especially in the case of the addition of 20 wt% synthetic brucites in epoxy mortar binders, from FH-3 to FH-1 reduction in the horizontal burning classification,5.5% improvement in limiting oxygen index,15% increment in tensile strength were obtained.