Tensile test on interlayer materials for laminated glass under diverse ageing conditions and strain rates Xavier Centelles a , Marc Martín a , Aran Solé b , J. Ramon Castro a , Luisa F. Cabeza a,⇑ a GREiA Research Group, INSPIRES Research Centre, University of Lleida, Pere de Cabrera s/n, 25001 Lleida, Spain b Department of Mechanical Engineering and Construction, Universitat Jaume I, Campus del Riu Sec s/n, 12071 Castelló de la Plana, Spain highlights  A tensile test was performed on seven laminated glass interlayer materials.  The mechanical properties of the materials were affected by the elongation rate.  EVALAM, EVASAFE and TPU were the least affected by ageing factors.  Water immersion led to water absorption and transparency loss for SentryGlas and PVB.  Mechanical properties of SentryGlas and PVB dropped after water immersion. article info Article history: Received 7 November 2019 Received in revised form 19 January 2020 Accepted 20 January 2020 Keywords: Laminated glass Polymeric interlayer Glass transition temperature Tensile test Ageing test abstract Laminated glass is obtained by bonding two or more glass layers with a polymeric interlayer. The cou- pling between glass layers depends on the shear stiffness of the interlayer. The mechanical and optical properties of the interlayer may be affected by weathering factors. Since interlayer materials are vis- coelastic, the strain rate may also affect its stiffness and ultimate strength. In this paper, tensile tests are conducted on seven different polymeric films (PVB BG-R20, PVB DG-41, PVB ES, SentryGlas, EVASAFE, EVALAM 80, and TPU) at three different strain rates. The mechanical and optical properties of unaged specimens are compared with specimens exposed to thermal cycles, high temperatures, and moisture. The unaged specimens of PVB DG-41, PVB ES, and SentryGlas had the highest stiffness, EVALAM 80 and EVASAFE had the highest ductility, PVB and SentryGlas had the highest tensile strength, and EVALAM 80, EVASAFE, and TPU were less affected by ageing factors and strain rate. Ó 2020 Elsevier Ltd. All rights reserved. 1. Introduction Laminated glass is a composite material consisting of two or more glass layers bonded using a polymeric film as interlayer. It was originally used in car windshields, because the polymeric interlayer prevented glass shards from scattering in case of acci- dental breakage. The first interlayer used was polyvinyl butyral (PVB). The application of laminated glass later expanded to archi- tecture, and new interlayer materials were developed to increase some laminated glass properties such as the transparency, the flex- ural stiffness, the post-breakage strength, and the adhesion to other materials, like steel or timber. Nowadays, the most com- monly used polymer groups for laminated glass interlayers are polyvinyl butyral (PVB), ethylene–vinyl acetate (EVA), thermoplas- tic polyurethane (TPU), and ionoplast (e.g. SentryGlas). Glass is a brittle material, and its fracture is difficult to predict [1], because it is generally caused by the formation and propaga- tion of surface flaws [2]. The mechanical behaviour of glass is linear elastic until breakage. By contrast, the polymeric interlayers are viscoelastic materials, which means that its mechanical response has an elastic and a viscous component: the elastic response is pro- portional to the strain, whereas the viscous component is propor- tional to the strain rate. The mechanical response of viscoelastic materials is time- and temperature-dependant [3]. Dynamic mechanical analysis (DMA) allows doing a characteri- zation of the thermo-viscoelastic properties of polymers. Andreozzi et al. [4] performed dynamic torsion tests on laminated glass specimens, and Pelayo et al. [3] performed dynamic tensile tests on polymeric interlayer films. Callewaertet al. [5] evaluated the influence of load duration and temperature on laminated glass plates under flexural load. Some interlayer manufacturers provide the value of the Young modulus (elastic component) as a function of the load duration time and working temperature (Fig. 1). https://doi.org/10.1016/j.conbuildmat.2020.118230 0950-0618/Ó 2020 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: lcabeza@diei.udl.cat (L.F. Cabeza). Construction and Building Materials 243 (2020) 118230 Contents lists available at ScienceDirect Construction and Building Materials journal homepage: www.elsevier.com/locate/conbuildmat