Viscoelastic characterisation of transparent binders for application on solar roads

Abstract

Polyurethanes are versatile materials and, in civil engineering, they are implemented as bonding elements, injection material to stabilise soil condition, as well as insulating and coating foams. Because of their good adhesion, their transparency, and their mechanical and thermal properties, the idea of the present research is to use it as organic matrix in a glass aggregates/glue composite used as a semi-transparent pavement surface layer. This research takes part in a wider project aiming at designing a hybrid pavement system able to harvest energy from the sun. The aim of this paper is to characterise four different types of thermoset polyurethanes in terms of curing time and visco-elastic properties. For this purpose, an experimental campaign was conducted, performing tests in a dynamic shear rheometer and a dynamic mechanical analysis. Curing time kinetics, defined as the evolution of phase angle, were modelled according to the Arrhenius law. Temperature and frequency dependence on the complex modulus were finally measured. The results demonstrate the strong dependency of the polyurethanes behaviour, overall mechanical performance and especially glass transition temperature, on the curing temperature.

Keywords:

• polyurethane
• solar road
• dynamic shear rheometer
• curing time

ORCID

Domenico Vizzari http://orcid.org/0000-0002-9878-053X

Additional information

Funding

The research presented in this paper is part of SMARTI ETN. SMARTI ETN project has received funding from the European Union’s Horizon 2020 Programme under the Marie Skłodowska-Curie actions for research, technological development and demonstration, under grant number 721493.