•Different laminated glass interlayer materials (PVB, EVA, SGP, and TPU) are studied.•The review provides a chemical overview and the main material characteristics.•Interlayer characterization ...methods are reviewed and classified.•Effects of ageing, mechanical properties, and recyclability are taken into account.•The review focuses on laminated glass in the building sector.
Laminated glass is obtained by bonding two or more glass layers using a polymeric interlayer. Compared to monolithic glass, laminated glass is beneficial in terms of post-breakage safety, security against break-ins, and acoustic insulation, among others. That is why laminated glass is being used for a wide variety of constructive solutions. Polymers such as PVB, ionomers, EVA and TPU are used as interlayer materials in laminated glass. This review aims to describe the most common polymeric interlayers, outline its characterization techniques, and give a general overview about the recyclability of the interlayers. There are two main properties used to characterize the interlayer materials: mechanical properties and resistance to ageing factors. Main mechanical tests found in the literature are summarized, and the properties studied in each of them are listed. Most experimental studies regarding ageing resistance consider mainly three weathering agents: humidity, UV radiation, and temperature.
•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.
Laminated glass is obtained by bonding two or more glass layers with a polymeric interlayer. The coupling 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 viscoelastic, 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.
•A 3×1.5 m2 laminated glass slab was tested under long-term loading.•Both creep after loading and deflection recovery after unloading were measured.•Each of the three laminated glass plates had a ...different interlayer material.•The deflection of each plate was simulated using a Finite Element Model.•The simulation was more accurate during loading-creep than unloading-recovery.
The mechanical behaviour of laminated glass plates and beams is affected in different ways by the shear stiffness of interlayer materials. Polymeric interlayers are viscoelastic materials, and therefore experience creep when subjected to long-term loading. In this paper, three laminated glass panels, each with a different interlayer material (PVB Clear, PVB ES, and SentryGlas), were placed between two laminated glass beams. A uniformly distributed load was applied during four months to study the effect of creep, and then was removed to see the deflection recovery during one month. The midspan vertical displacement of the two laminated glass beams remained almost constant over time, with a small variation that was attributed to the rubber sheets placed in the supports. The plate with SentryGlas had the lowest elastic deformation, creep, and residual deformation. The plate with PVB Clear had the highest elastic and total deformation. The plate with PVB ES had a similar initial deflection as SentryGlas, but was the one that experienced the highest creep. At the end of the test the plates still had a small residual deflection, which could be due to an incomplete deflection recovery. The flexural behaviour of the three laminated glass plates was simulated using a Finite Element Model, representing the loading, the creep, the unloading, and the deflection recovery stages.
•Glass joint performance is defined by pre- and post-breakage strength and stiffness.•In adhesive joints, full cohesive failure inside the adhesive layer is desirable.•Weathering conditions may ...deteriorate adhesive and laminated joints.•In the long term, pre-compressed joints may be affected by stress relaxation.•The most common breakage cause in bolted joints is glass fracture at the borehole.
In order to increase transparency in buildings, structural elements made of laminated glass are being developed. The recent technological improvements in terms of material research, fabrication processes, and construction techniques, are creating new design opportunities for laminated glass structural elements. For laminated glass, the post-breakage strength and safety are important because of the brittle nature of glass, especially in structural applications. The connection between elements is a critical part, because high loads are concentrated in small surfaces, leading to local peak stresses. In this review, different connection types for structural glass elements are presented, and their performance is evaluated. Most common connection types are mechanical, adhesive, and laminated. The main goal of this review is to compare the experimental results obtained from different types of connections, evaluating the type of test, the materials used, the pre- and post-breakage performance, the failure mode, and the influence of ageing factors and load duration.
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•Laminated glass double-lap shear specimens with four interlayers were tested.•The type of interlayer material affected the maximum load and breakage mode.•Humidity and long-term UV ...radiation had a negative effect on some specimens.•The strength either increased or remained unaffected by thermal cycles.•The stress distribution was not homogeneous in the glass-interlayer interface.
Laminated glass is a composite laminate obtained from combining two or more glass layers with a polymeric interlayer. The adhesion between glass and interlayer, as well as the shear strength and stiffness of the interlayer, are key factors to evaluate the cohesive behaviour of laminated glass. Glass is a very durable material, while polymeric interlayers can be deteriorated by exposure to weathering factors. A double-lap shear test was carried out on laminated glass specimens, with four different interlayer materials (PVB BG-R20, Saflex DG-41, SentryGlas, and EVASAFE), after different ageing tests (unaged, thermal cycles, humidity, and UV radiation). The material selection affected the shear behaviour of the bond between glass and interlayer, and so did the previous exposure to certain ageing factors. Since the polymeric interlayers are viscoelastic materials, and therefore its mechanical properties are time- and temperature-dependant, the results here presented should be complemented with dynamic and static tests at different temperatures.
•Stress relaxation tests were conducted on seven laminated glass interlayers.•The master curves were obtained by using the t-T-P shifting (CFS) algorithm.•The stiffness of all tested interlayers ...decreased over time and temperature.•An equation to fit each relaxation master curve was represented by a Prony series.•The storage and loss modulus were obtained by using interconversion methods.
The mechanical behaviour of laminated glass is strongly affected by the polymeric interlayer placed between glass layers. In general, this interlayer is a viscoelastic material, and therefore it may experience creep and stress relaxation when subjected for an extended period to a constant stress or strain respectively. In this study, seven different commercial interlayer materials (EVALAM, EVASAFE, PVB BG-R20, Saflex DG-41, PVB ES, SentryGlas, and TPU) were evaluated with relaxation tests at different temperatures, in order to build the relaxation master curves through the time-temperature superposition principle. A generalized Maxwell model was chosen to describe the viscoelastic behaviour of the tested materials. This paper includes the coefficients of the Prony series that fit better the experimental results. This paper has two main goals. First, to present the Prony coefficients (ei and τi), which can then be used to create numerical models that take into consideration the time and temperature-dependant behaviour of the interlayer. Second, to provide the two components of the complex modulus (E*(ω)) of each material, the storage modulus (E’(ω)) and the loss modulus (E’’(ω)), which can be obtained from the relaxation modulus (E(t)) by using analytical interconversions.
Laminated glass beams without metallic or polymeric reinforcements generally lack post-breakage strength and ductility. This paper aims to perform a comparative study by testing five different fully ...transparent laminated glass beam designs in order to see how parameters such as the number and thickness of glass sheets (3 x 10 mm or 5 x 6 mm), the interlayer material (PVB Clear or SentryGlas), and the thermal treatment of glass (annealed or heat-strengthened) affect the pre-breakage performance and post-breakage safety. A buckling analysis is also performed using a numerical model with ABAQUS CAE. The study includes a comparison between the results of different experimental mechanical tests on laminated glass beams, including the tests presented in this paper, as well as other tests found in the literature. All designs presented a linear elastic behaviour until initial breakage. The interlayer material mainly affected the crack shape of laminated glass beams. Beams with five sheets of annealed glass had a more progressive breakage, and therefore a safer behaviour, than beams with three sheets of annealed or heat-strengthened glass.
Patulin, a mycotoxin produced primarily by
Penicillium expansum, is currently of great concern because of its undesirable effects in human health. It has been proven that patulin can damage organs ...and tissues in animals and some studies revealed carcinogenic and teratogenic effects. Patulin is found mainly in low quality apples diverted to production of apple by-products. Apples from cold storage or recently harvested (usually ground harvested or low quality apples) are stored under ambient conditions (deck storage) until they are processed. The present assay studies the consequences of this type of storage in development of lesions and patulin accumulation.
The assayed factors were the size of lesions when apples were taken out from cold storage, time the apples stayed at room temperature after cold storage (as a simulation of deck storage) and intraspecific differences between 2 isolates of
P. expansum. A sublot of
P. expansum inoculated apples was cold stored until lesions achieved concrete sizes. Then, apples were either transferred to a 20 °C storage room for 0 to 5 days or were analysed for patulin immediately. The rest of the apples were directly stored at 20 °C. Each treatment had three replicates.
Increase of lesion size with time at 20 °C depended on initial lesion size after cold storage. Bigger lesions were always achieved in apples with bigger initial lesion size. Initial lesion size and time at 20 °C significantly influenced patulin accumulation. No significant amounts of patulin were found in apples with lesions up to 2 cm after cold storage. Patulin amounts significantly increased on the 2nd day at 20 °C day and remained constant until the 5th day. Patulin accumulation tended to be higher when initial lesions were bigger.
The assay showed the influence of apple quality (measured as overall lesion size) after cold storage on patulin accumulation during deck storage, as well as the importance of duration of deck storage. Quality of apples entering the processing plant should be assessed in order to program deck storage and minimise patulin accumulation. Predictive models of patulin accumulation as a function of time at room temperature and apple quality should be a useful tool to elaborators.
We derive a new equation of state (EoS) for neutron stars (NS) from the outer crust to the core based on modern microscopic calculations using the Argonne v18 potential plus three-body forces ...computed with the Urbana model. To deal with the inhomogeneous structures of matter in the NS crust, we use a recent nuclear energy density functional that is directly based on the same microscopic calculations, and which is able to reproduce the ground-state properties of nuclei along the periodic table. The EoS of the outer crust requires the masses of neutron-rich nuclei, which are obtained through Hartree-Fock-Bogoliubov calculations with the new functional when they are unknown experimentally. To compute the inner crust, Thomas-Fermi calculations in Wigner-Seitz cells are performed with the same functional. Existence of nuclear pasta is predicted in a range of average baryon densities between ≃0.067 fm-3 and ≃0.0825 fm-3, where the transition to the core takes place. The NS core is computed from the new nuclear EoS assuming non-exotic constituents (core of npeμ matter). In each region of the star, we discuss the comparison of the new EoS with previous EoSs for the complete NS structure, widely used in astrophysical calculations. The new microscopically derived EoS fulfills at the same time a NS maximum mass of 2 M⊙ with a radius of 10 km, and a 1.5 M⊙ NS with a radius of 11.6 km.
We describe a relation between the symmetry energy coefficients c(sym)(rho) of nuclear matter and a(sym)(A) of finite nuclei that accommodates other correlations of nuclear properties with the ...low-density behavior of c(sym)(rho). Here, we take advantage of this relation to explore the prospects for constraining c(sym)(rho) of systematic measurements of neutron skin sizes across the mass table, using as example present data from antiprotonic atoms. The found constraints from neutron skins are in harmony with the recent determinations from reactions and giant resonances.
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