scholarly journals Influence of Load-bearing Structure on Size of Bonded Facade Cladding

2018 ◽  
Vol 163 ◽  
pp. 08003
Author(s):  
Pavel Liška ◽  
Barbora Nečasová ◽  
Jiří Šlanhof

Architecture has been an integral part of our lives ever since people first existed. Structures are required by both investors and society to have what is considered a highly modern appearance while maintaining elements of a long service life. To meet such requirements, it is necessary to use modern technologies and materials. Bonded joints represent one of the options. Unlike with mechanical joints, it is possible to use bonded joints to anchor large format cladding panels to bearing substructures of various shapes and sizes. The design is simple, but very technically demanding to implement. One of the factors which have an impact on both the design and its implementation is the bearing substructure itself. As part of a research project, a load bearing substructure made from wood and aluminium alloy was tested. The test results prove that the mechanical properties of the materials used, especially their thermal and moisture expansion, directly influence the size of the cladding. In the case of a bearing substructure made from wood, the cladding may be larger by several percentage points than in the case of a bearing substructure made from aluminium alloy.

2018 ◽  
Vol 776 ◽  
pp. 15-22
Author(s):  
Barbora Nečasová ◽  
Pavel Liška ◽  
Michal Novotný

Building structures have been designed such that they are able to withstand the adverse effects of the environment for a certain time. The terms "for a certain time" and "the surrounding environment" are used for a purpose here, and that is because the phenomenon of ageing buildings is currently an increasingly discussed problem that is faced by every larger city. The materials used in the buildings, such as façade cladding, age just as the buildings themselves do. An immense pressure has been currently put on designers to use environmentally friendly materials not only for new buildings but also for the retrofitting of existing ones. The aim of this paper is to demonstrate that wood or wood composite materials are convenient solution for restoration of façades of administrative or commercial buildings, however, since the new cladding have to be connected with an old load-bearing structure, the designers have to overcome many limitations. One of the main difficulties is high thermal and moisture expansion of these materials which has a direct impact on the appearance of the façade. The obtained results showed that expansion properties should be studied closely when using wooden elements in the design and that a neglection can lead to a premature failure of the system.


2015 ◽  
Vol 804 ◽  
pp. 129-132
Author(s):  
Sumrerng Rukzon ◽  
Prinya Chindaprasirt

This research studies the potential for using waste ash from industrial and agricultural by-products as a pozzolanic material. Classified fly ash (FA) and ground rice husk ash (RA) were the materials used. Water requirement, compressive strength and porosity of cement mortar were investigated. Test results indicated that FA and RA (waste ash) have a high potential to be used as a good pozzolanic material. The water requirement of mortar mix decreases with the increases in fly ash content. For ground rice husk ash (RA), the water requirement of mortar mix increases with the increases in rice husk ash content. In addition, the reduction in porosity was associated with the increase in compressive strength.


2017 ◽  
Vol 2017 ◽  
pp. 1-20
Author(s):  
Ulf Arne Girhammar ◽  
Bo Källsner

The authors present an experimental and analytical study of slotted-in connections for joining walls in the Masonite flexible building (MFB) system. These connections are used for splicing wall elements and for tying down uplifting forces and resisting horizontal shear forces in stabilizing walls. The connection plates are inserted in a perimeter slot in the PlyBoard™ panel (a composite laminated wood panel) and fixed mechanically with screw fasteners. The load-bearing capacity of the slotted-in connection is determined experimentally and derived analytically for different failure modes. The test results show ductile postpeak load-slip characteristics, indicating that a plastic design method can be applied to calculate the horizontal load-bearing capacity of this type of shear walls.


2020 ◽  
Vol 47 (3) ◽  
pp. 275-282
Author(s):  
Dewi Andriani ◽  
Desta Wirnas ◽  
Dan Trikoesoemaningtyas

Sorghum has a growing popularity for food, feed, biofuel, and therefore needs to be developed. The research aimed to compare the effectiveness of pedigree and modified bulk selection methods for improving yield in three sorghum populations. The genetic materials used were 60 F6 lines from three populations, namely PI 10-90-A x Numbu, PI 150-20-A x Numbu and PI 150-20-A x Kawali which had been selected using pedigree and modified bulk methods. The experiment was conducted from October 2018 to February 2019 at the Cikabayan Experimental Station of IPB University, Dramaga, Bogor. The experiment was arranged in an augmented design with six checks, namely Kawali, Numbu, PI 10-90-A, PI 150-20-A, Samurai 1, and Samurai 2 which were replicated four times. Observations were made on agronomic traits and yield. Plant height and grain weight per panicle had high heritability and large genotypic coefficients of variation. The contrast test results showed significant differences between populations in plant height, panicle length, days of harvesting and 100-seed weight. On the other hand, no significant difference was observed among selection methods, indicating that both methods were equally effective for increasing sorghum yield. The pedigree selection and modified bulk selection increased grain yield per panicle by 14.1 g and 18.2 g respectively. Bulk of the best genotypes in early generation could be an alternative of bulk selection method. Keywords: contrast test, differential selection, genotypic coefficient of variation, heritability


2022 ◽  
Vol 14 (2) ◽  
pp. 895
Author(s):  
Dshamil Efinger ◽  
Andreas Ostertag ◽  
Martin Dazer ◽  
David Borschewski ◽  
Stefan Albrecht ◽  
...  

The consumption of construction materials and the pollution caused by their production can be reduced by the use of reliable adaptive load-bearing structures. Adaptive load-bearing structures are able to adapt to different load cases by specifically manipulating internal stresses using actuators installed in the structure. One main aspect of quality is reliability. A verification of reliability, and thus the safety of conventional structures, was a design issue. When it comes to adaptive load-bearing structures, the material savings reduce the stiffness of the structure, whereby integrated actuators with sensors and a control take over the stiffening. This article explains why the conventional design process is not sufficient for adaptive load-bearing structures and proposes a method for demonstrating improved reliability and environmental sustainability. For this purpose, an exemplary adaptive load-bearing structure is introduced. A linear elastic model, simulating tension in the elements of the adaptive load-bearing structure, supports the analysis. By means of a representative local load-spectrum, the operating life is estimated based on Woehler curves given by the Eurocode for the critical notches. Environmental sustainability is increased by including reliability and sustainability in design. For an exemplary high-rise adaptive load-bearing structure, this increase is more than 50%.


Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7318
Author(s):  
Anita Ptak ◽  
Paula Taciak ◽  
Wojciech Wieleba

This article concerns the tribological properties of three selected polymer materials: polyamide PA6, polyethylene PE-HD and polyetheretherketone composite PEEK/BG during sliding against aluminium alloy EN AW-2017A in the presence of hydraulic oil HLP 68. The tests were carried out under contact pressure p of 3.5–11 MPa at ambient temperature T ranging from −20 °C to +20 °C. The dependence of kinetic friction coefficient μk on the two parameters was determined through tribological tests carried out using a pin-on-disc tribometer. A five-level central composite rotatable design (CCRD) was adopted for the experiment. All the test results were statistically analysed. The microhardness of the surface of the polymeric material was measured before and after the friction process. The surface was also examined under SEM. Temperature and contact pressure have been found to have a significant effect on the tribological properties of the tested sliding pairs. Relative to the applied friction conditions, the surfaces after friction showed rather heavy signs of wear.


2002 ◽  
Vol 49 (3-4) ◽  
pp. 75-80 ◽  
Author(s):  
Dejan Markovic

Evaluation o f cytotoxicity is a first step in assessment of dental materials biocompatibility. Necessity for unique criteria in researches resulted in international standard methodology (ISO). The aim of this study was to assess the cytotoxicity of four restorative materials (three glas ionomer cements and one composite material) and to define adventages and disadventages of common ISO methodology for evaluation of this aspect of dental materials biocompatibility. Research was designed according to ISO/TC 106/1995 and ISO/ 10993-5/1994 methodology. Materials used in this investigation were Fuji IILC (GC), Vitiemer (3M), Ionosit fill (DMG-Hamburg), Luxat (DMG-Hamburg). Evaluation of cytotoxicity was carried out on standardized Human Diploid Cell Lung WI-38. Obtained results showed expressive cytotoxic effect of all investigated materials without statisticaly significant difference. Estimation of material biocompatibility and assessment of obtained results can be made only after establishment of correlation with test results. Common ISO methodology is simple for conductance and reproduction, and use of cell cultures in researches is painless, cost effective and without moral or ethical dilemma.


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