Transparent polymer interlayers are usually adopted to laminate glass members dealing with structural roles. Currently, they are also used to realize laminated adhesive connections joining structural glass components (e.g. steel-to-glass connections). Research activities are currently ongoing to investigate the behavior of such joints, made either by a transparent ionomer (SentryGlas® from DuPont) or by transparent silicon (TSSA from DowCorning). The experimental investigations of the bulk material properties of SG and TSSA laminated interlayers are here presented. Uniaxial tensile tests on dumbbell shaped specimens are performed to study the mechanical properties and constitutive law of adhesive materials. The effect of temperature and strain rate are investigated and discussed. The specimens were previously cured to bring the polymeric material in the same state as it is in connections after lamination. Real stresses are calculated taking into account the transversal contraction of the material and the actual cross section of the specimens under large deformations by means of Digital Image Correlation.

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The durability of laminated glass is a relevant problem in modern structural engineering. This paper deals with the results of experiments on laminated glass durability focusing on the following impacts: temperature, humidity, UV radiation and combination of these impacts. The purpose of this research is to investigate the aspect of laminated glass durability in the framework of long-term tests. Three different interlayer laminates were used during the experiments: Polyvinyl butyral (PVB), Ethylene vinyl acetate (EVA), DuPont's SentryGlas ionoplast (SG) and 6 mm thick tempered Soda-Lime-Silica Glass. Tests for environmental condition impact and durability of laminated glass are foreseen according to standard (ISO 12543- 4:2011). Bending tests were carried out due to standard (EN 1288-3:2000). Brief graphical comparison of the experimental results is presented in the paper.

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In this study the structural response of post-tensioned structural glass beams is investigated. This is done through four-point bending tests on two series of post-tensioned glass beam specimens. The beams consist of three layers of annealed float glass and are posttensioned by means of two stainless steel tendons positioned along the upper and lower edge of the beams. In addition, a series of reference beams, with identical geometry but without tendons, is tested. From the results it is concluded that post-tensioning a glass beam is a feasible concept, which provides the beams enhanced initial breakage strength and enhanced post-breakage performance. More specifically, the post-tensioned beams reach up to 80% higher initial breakage loads than the reference beams. Furthermore the post-tensioned glass beams reach postbreakage load levels up to 200% of their initial glass breakage load and demonstrate highly ductile post-breakage response. Further studies will focus in more detail on this promising concept of post-tensioning glass beams.@en

This paper presents the results of long term experiments of four point bending test with structural laminated glass plates. For experiments 6 mm thick annealed Soda-Lime-Silica Glass and three different interlayer laminates were used: Polyvinyl butyral (PVB), Ethylene vinyl acetate (EVA), DuPont's SentryGlas (SG). These types of laminates were chosen because there is a wide range of their possible practical application in buildings' constructions. Bending creep tests were carried out by applying the four point bending test model. Applied dimensions of the laminated glass plates and loading scheme are from the standard EN 1288-3. Three specimens were tested with the same interlayer laminated glass plates. Tests were successively carried out at three temperatures: + 20°C, + 30°C, + 40°C. Every test took 24 hours interval at each temperature, so in total one full experiment took 72 hours with one type of interlayer. The deflections at the middle of specimens, volatile displacement between two glass sheets and longitudinal strains at the middle of the laminated plate were measured. In the paper the comparisons of the experimental results between the glass panels with various laminates and at different temperatures are presented.

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The recent demand for architectural transparency has drastically increased the use of glass material for structural purpose. However, connections between structural glass members represent one of the most critical aspects of glass engineering, due to the fragile behaviour of this material. In that regard, research activities on a novel type of metal-to-glass adhesive connections (called laminated connections) are currently on-going at EPFL. These joints make use of transparent thin polymer foils - i.e. an ionomer polymer (SentryGlas® from Dupont) and a structural silicon (TSSA from Dow Corning) - that are cured by an autoclave lamination process. The research activities involve both experimental and numerical studies with the aim to develop a design model and failure criterion for laminated connections. In this paper, the nonlinear numerical investigations on the behaviour of this type of adhesive joints are presented. In particular, the effects of mechanical and geometrical parameters on the response of the laminated connections are studied by non-linear modeling. The results are obtained performing several numerical simulations varying the parameters' values and monitoring the related effects. Strong non-linearity in both strain and stress field distributions are observed, even in case of simple load conditions. The results suggest that, with the purpose of performing numerical-experimental comparisons, precise measurements have to be performed since very small displacements are to be expected. Additionally, an appropriate modeling of both boundary conditions (realized by the test setup) and adherents' deformations (of both steel and glass adherent) is necessary.@en

In modern buildings, glass is increasingly used as a load-carrying material in structural components, such as glass beams. For glass beams especially the edge strength of glass is important. However, the strength of glass is not a material constant but depends on various parameters, which makes glass, amongst other things, a challenging building material. One of the parameters influencing glass strength is the combination of humidity and stress, which may cause stress corrosion. The aim of the current study is to limit the effect of humidity at the glass edge. This is done by the application of a protective coating. In this exploratory study several coating solutions are tested applying the coating at the edge of glass specimens. These specimens are then subjected to in-plane four-point bending tests to determine their failure strength. The effects of the coatings on the edge strength are analyzed using the failure strength data from the bending tests. The results indicate that only one of the tested coatings has an effect on the glass edge strength.@en