Thermal, damping, and mechanical properties of thermosetting epoxy-modified asphalts

Transportation Research Record

Kasbergen

et al. 2018

The chemical irreversible hardening of epoxy modified bitumen is affected by various physical factors and the successful application of this technology is directly linked with full understanding of chemo-rheological material characteristics. This study proposes a model to describe the material viscosity evolution during hardening of epoxy modified bitumen. The findings from numerical analyses performed to assess the mechanical response of epoxy modified bituminous binders are presented. Information of the chemical interaction of epoxy within a bituminous matrix was collected and all the influential factors have been determined. The proposed chemo-rheological model accounting for the polymerization of the epoxy in the bitumen was formulated and the sensitivity of material parameters, such as activation energy, reaction order and extent of hardening reaction until the gel point of epoxy modified binders, was demonstrated. Results of the analyses suggest that lower levels of activation energy increase the degree of hardening and the rate of viscosity development. By decreasing the hardening reaction until the gel point the achieved viscosity of epoxy modified bitumen was increased showing the importance of gel reaction extent on material viscosity evolution. The numerical studies have shown also that the polymerization rate in the epoxy modified bitumen is highly dependent on the temperature under various (non-) isothermal conditions. Also, the polymerization rate should be considered through all the material curing processes to avoid unwanted variations in the mechanical properties.

Section: Chemo-rheological Equationmentioning

confidence: 51%

Chemo-Rheological Study of Hardening of Epoxy Modified Bituminous Binders with the Finite Element Method

Apostolidis

Transportation Research Record

Kasbergen

et al. 2018

“…It is well known that glass transition of polymers relies on the mobility of polymer segments. In the present case, the rigid nanofibers on the PU chains restrict molecular chain mobility of polymer matrix and result in the increment of T g [34,35]. The relationship between T g of the soy polyol-based PU nanocomposite with different hydroxyl value and CNF content is shown in Fig.…”

Section: Glass Transitionmentioning

confidence: 71%

Carbon nanofibers reinforced soy polyol-based polyurethane nanocomposites

Wang

et al. 2015

J Therm Anal Calorim

Self Cite

Vapor-grown carbon nanofiber (CNF)-modified soy polyol-based polyurethane (PU) nanocomposites with different hydroxyl value of polyols (OH) were synthesized. The glass transition, thermal stability, mechanical properties, and morphology of the PU nanocomposites were characterized through differential scanning calorimetry, thermogravimetry, universal test machine, and scanning electron microscopy. The addition of CNFs increased the glass transition temperature as well as significantly improved tensile strength and Young's modulus of PU nanocomposites. Meanwhile, thermal and mechanical properties of PU composites were influenced by the different hydroxyl value of polyols due to those different structures. In particular, in the case of 2 mass% CNF addition in PU derived from soy polyol with the OH number of 164 mg KOH g -1 , 20.8°C improvement in the glass transition temperature, 115 % increment in tensile strength, and nearly eightfold increase in Young's modulus were obtained.

“…This result agreed well with the effect of the base asphalt on the tensile strength of the neat epoxy for EA binders. On the contrary, the addition of base asphalt increased the elongation of the neat epoxy for EA binders . For EAAs, both the tensile strength and elongation at break increased with increasing asphalt penetration grades; this may have been related to the homogeneous dispersion of spherical asphalt particles for EAA with higher penetration grade within the epoxy matrix, as discussed later.…”

Section: Resultsmentioning

confidence: 92%

“…It is well accepted that the performance of EA depends on the physical properties of both the asphalt and epoxy resin . Asphalt is a complex material.…”

Section: Introductionmentioning

confidence: 99%

Viscous, damping, and mechanical properties of epoxy asphalt adhesives containing different penetration‐grade asphalts

Sun

Gong

J of Applied Polymer Sci

et al. 2018

Self Cite

Epoxy asphalt adhesive (EAA) is a thermosetting polymer modified asphalt that has been widely applied on steel bridge decks as a strong adhesive and waterproof layers. In this study, the influence of the asphalt penetration grade on the viscosity, damping and mechanical properties, bond strength, and microstructures of EAAs was investigated. The viscosity of the EAAs increased with increasing asphalt penetration grade. The presence of base asphalt increased the glass-transition temperature (T g ) of the neat epoxy. The asphalt penetration grade had a negligible effect on the T g values of the EAAs. The existence of base asphalt improved the damping behaviors of the neat epoxy. Moreover, the damping properties of the EAAs increased with increasing asphalt penetration grade. The tensile strength, elongation at break, and bond strength values of the EAAs increased with increasing asphalt penetration grade. The bond strengths of the EAAs were 7-to 10-fold higher than that of the neat asphalt. The asphalt penetration grade had a negligible effect on the bond strengths of the EAAs. Morphological observations revealed that the average size of the dispersed asphalt particles in the epoxy decreased with increasing asphalt penetration grade. A more homogeneous phase separation was formed in the EAA with a higher penetration-grade asphalt.