Laminated Glass Beams Subjected to Artificial Solar Radiation

In the long run laminated glass interlayers are sensitive to weather conditions. Several studies have been carried out that aim at understanding the consequences of moisture and solar radiation on adhesion to glass and on the mechanical response of the composite pane. In particular, solar radiation seems to produce the strongest effects on the bulk properties of PVB, modifying the coupling capability of laminated glass plates exposed to the direct sunlight. Such problem has been already studied by the authors via dynamic tests on small laminated glass specimens subjected to artificial UV light; however, due to the methodology of these mechanical tests, it was not possible to repeat the experiment on the same specimens subjected to different exposition times, and it was not possible to investigate the laws of accumulation of the consequences of weathering actions. In fact, solar radiation could produce different effects on the structure of material, but only superimposed consequences can be observed. In order to better understand the time progression of the phenomenon, creep tests were performed on laminated glass beams subjected to four-point bending; the specimens were tested in correspondence of definite time intervals of UV exposure. The total amount of time will be defined according to the observed variation of test results with respect to the total exposure. The effects of UV radiation are highlighted directly comparing the displacement history diagram and successively evaluated analyzing the mechanical parameters that describe the rheological behavior

Retrofit Strategies for the Improvement of Visual Comfort and Energy Performance of Classrooms with Large Windows Exposed to East

AbstractThe typical orientation of the facades of school buildings, along with the presence of large windows and permanent position of the students, can create uncomfortable environmental conditions caused by eye strain due to glare and local thermal discomfort due to asymmetrical thermal radiation. In this work, the effectiveness of various types of high performance glazing and external shading is evaluated, by means of simulations of visual comfort and energy efficiency. Simulations were carried out for a case study which is representative of a typical classroom of a school, located in a town of Tuscany, where instrumental monitoring of existing thermal and lighting conditions was conducted. The case study was selected through an analysis of energy consumption of the whole school building stock of the city, over a period of five years. The analysis has allowed to select the most critical one in terms of energy consumption and the most representative one regarding the Italian school building stock. The selected building has been analyzed by means of building performance simulation software. A survey about the school users’ perception of comfort levels was also carried out by means of questionnaires

Comparison among detailed and simplified calculation methods for thermal and energy assessment of the building envelope and the shadings of a new wooden nZEB house

This paper deals with research carried out by the University of Florence on the thermal and energy performances of a recently built nZEB in Mediterranean Italian area. Heterogeneous component and thermal bridges performances have been analysed and critically evaluated with different calculation methods, and the results in terms of energy consumptions for heating and cooling have been compared. Some solar shading devices have been evaluated to reduce the building energy need for cooling. Main results of the research are presented for the components and thermal bridges properties and for the energy balance of the building implemented with different solar shadings