The construction and building sector is responsible for a large share of energy and material used during the life cycle of a building. It is therefore crucial to apply a circular economy model within the process wherever possible to minimize the impact on the environment. In this paper, the possibility of producing thermal and acoustic boards from industrial nonwoven waste textile is studied and presented. The nonwoven polyester textile obtained directly from the production line in the form of strips and bales was first shredded into smaller fractions and then in the form of pile compressed with a hot press to form compact thermal insulation boards. The first set of specimens was prepared only from waste polyester nonwoven textile, whereas the second set was treated with sodium silicate in order to check the material’s reaction to fire performance. The experimental work was conducted to define the acoustic properties, reaction to fire behavior and thermal conductivity of the produced specimens. The obtained results show that the thermal conductivity coefficient of specimens without added water glass dissolution is near to the values of conventional materials used as thermal insulation in buildings. The reaction to fire testing proved that the addition of water glass actually propagates the progressive flame over the entire product. It can be concluded that the presented thermal insulation can be used as an adequate and sustainable solution for building construction purposes.
Non-structural masonry partition walls, which are mainly designed to functionally separate spaces in the buildings and provide physical barriers between rooms, were traditionally built from either solid or hollow clay units or autoclaved aerated concrete blocks. Recent earthquakes have revealed the high vulnerability of these elements, even in the case of low to moderate seismic events. Public buildings (e.g., hospitals and schools) are particularly vulnerable. Due to their greater floor-to-floor heights and the response spectra of floors, the dynamic response of primary structure may provoke significantly higher seismic loads on partition walls. The main goal of the presented experimental study was to investigate the behavior of slender partition walls loaded out-of-plane with a simple and cost-effective approach that may be applied through routine refurbishment works. Eleven full-scale slender non-structural masonry partition walls were built with brickwork and cement–lime mortar. Eight of them were additionally strengthened with different techniques, including glass fiber-reinforcing fabric and low-cost glass fiber-rendering mesh. To evaluate the efficiency of the applied strengthening solutions, out-of-plane quasi-static cyclic experiments were conducted. By applying meshes over the entire surfaces, the resistance was significantly improved with the low-cost approach reaching half of the resistance of the commercially available strengthening system preserving the same displacement capacity.
The retrofitting of cultural heritage buildings for energy efficiency often requires the internal thermal insulation of external walls. Most of the in situ studies of capillary active interior insulation were performed in mild oceanic climate regions, and they showed an excellent performance. However, as a large part of Central–Eastern Europe belongs to a continental climate with cold winters and long periods of temperatures below the freezing temperature, the applicability of the capillary active interior insulation in cold climate was studied. The hydrothermal behaviour of the three walls was determined—each consists of one of three different interior insulations—and the original wall is made of historic regular solid bricks. Two interior thermal insulations were capillary active (aerated cellular concrete, calcium silicate) and one vapour-tight (glass foam). A hot box–cold box experiment and a steady-state model were used to demonstrate an increase in the original wall mass due to the water condensation only when the capillary active interior insulation is used. The combination of the water condensation and the low sub-zero temperature may lead to a risk of freeze–thaw damage to the original wall. The numerical simulation of the water vapour condensation for the considered walls for the Slovenian town Bled with sub-zero average winter temperatures was performed to obtain the whole temperature and moisture profile. It showed good agreement between an experimentally and numerically obtained amount of water condensation. The capillary active interior insulation proved to be unsuitable for improving the thermal insulation of buildings in cold continental climate, and only a vapour-tight system can be recommended.
Bisphenol A (BPA) is a well-known synthetic compound that belongs to the group of endocrine-disrupting chemicals. Although bone tissue is a target for these compounds, studies on BPA-related effects on bone morphology in farm animals are limited. In this preliminary study, we investigated the effects of short-term dietary BPA exposure on femoral morphology, metabolism, mineral content, and biomechanical behavior in rams aged 9–12 months. Fourteen rams of the Istrian Pramenka breed were randomly divided into a BPA group and a control group (seven rams/group) and exposed to 25 µg BPA/kg bw for 64 days in feed. Blood was collected for determination of bone turnover markers (procollagen N-terminal propeptide, C-terminal telopeptide), and femurs were assessed via computed tomography, histomorphometry, three-point bending test, and mineral analysis. BPA had no significant effects on most of the parameters studied. Only mineral analysis showed decreased manganese (50%; p ≤ 0.05) and increased copper content (25%; p ≤ 0.05) in the femurs of BPA-exposed rams. These results suggest that a 2-month, low-dose exposure to BPA in growing rams did not affect the histomorphology, metabolism, and biomechanical behavior of femurs; however, it affected the composition of microelements, which could affect the histometric and biophysical properties of bone in the long term.
Non-structural masonry partition wall represents a relatively high risk for the occupants of the building even when subjected to the moderate earthquake loading due to its slenderness and brittle failure. The risk is higher for older public buildings where the non-structural partition walls are slenderer than in contemporary buildings and the importance of building is higher. Strengthening of the existing non-structural partition walls with glass fiber fabrics and façade meshes offers more sustainable option in comparison to their replacement by means of new drywall gypsum-card board walls and for that reason we conducted several out-of-plane cyclic tests to investigate the behavior of these walls in their weakest direction i.e. out-of-plane. All in all, eleven full scale partition walls were built with regular solid bricks and lime-cement mortar, where eight of them were strengthened with different glass fiber reinforcements and finally all tested under cyclic out-of-plane loading. The bond between the partition wall surface and reinforcing glass fiber fabric was ensured with the use of flexible polyurethane-based adhesive. Therefore, additional specially designed double leap shear-tensile test was conducted to evaluate the bond behavior. The bond between solid brick surface and glass fiber fabric tends to be stiffer in comparison to the option with glass fiber façade rendering mesh reinforcement. Results show that it is possible to provide a cost-effective improvement of the partition wall’s out-of-plane resistance by applying a simple glass fiber façade meshes with the use of flexible polyurethane adhesive.