Applied Mechanics and Materials Vol. 824

Abstract: Spray foam thermal insulations are one of new materials, which are now considerably applied in building practice and which are therefore also the aim of current research. In building practice is an effort to apply these materials to very rugged surfaces in both the external and the internal side of the structure. On the interior side, however, the application is connected with the risk of condensation, which is difficult to verify by the measurement. The contribution is focused just on the comparison of methods and measuring devices designed for immediate detection of moisture in the material of sprayed polyurethane foam. The samples of thermal insulation, which have undergone exposing of humidity in accordance with Czech Standards, were compared by the experimental assessment. The obtained results were compared and evaluated, while as expected, the moisture measuring of highly porous thermal insulation is significantly more difficult than the measuring of thermal insulations made of conventional homogeneous building materials.

Abstract: In the past, due to a harmonization of standards of the Slovak Republic to European Union standards, there was the amendment of Act no. 455/1991 Coll. on small business. Based on adjustments related regulations was a canceled competence requirement of persons performing regular cleaning and inspection of the chimney. According to statistics of Ministry of Interior of the Slovak Republic is a chimney still one of the most common reasons of fire in residential buildings. The article deals with the analysis of fires caused by chimneys and flues. The main goal is to point out the necessity to solve this problem by stricter regulations on testing and approval of the chimney.

Abstract: The authors of presented research case focused on possibilities of sealing porous as well as non – porous materials and analysed the measured results. It is the second article of the above mentioned authors dealing with sealed joints, however, in this case study the focus was placed on a group of industrially manufactured modified silyl polymer and polyurethane sealants. The research is based on the modified test procedure for the determination of adhesion and cohesion properties during maintained extension at variable temperatures, i.e. a high temperature of (70 + 2) °C and a temperature simulating freezing, i.e. (-20 + 2) °C, according to the European standard EN ISO 9047. The degree of specimen extension was set to amplitude of 20.0 % and the aim of the research case was to discover any differences that might appear in the resistance. The measured results demonstrate that there are significant differences between individual sealants in the results they provide in combination with specific material, e.g. wood appears to be a problematic substrate as well as glass cement or aluminium.

Abstract: This contribution focuses on the examination of the mutual dependence between the degree of modification of bitumen sheets and the strength characteristics of their mechanically fastened joints.Bitumen sheets with differently modified bitumen substances which were used as single-layer mechanically fastened waterproofing membranes for flat roofs were chosen as samples. The aforementioned dependence has been noted in practice, but until now has not been explicitly documented.The aim of this contribution is to confirm or to refute the hypothesis that a relation exists between the degree of modification of bitumen sheets and the strength of their joints. The formulation of the results was based on the statistical evaluation of laboratory measurement data.

Abstract: Thermal insulation effect of reflective insulation is based on the reflection of thermal radiation. Reflective insulations are mainly used in combination with the non-ventilated air cavity. Proposed paper deals with experimental measurements of the thermal insulation properties of the air cavity surrounded by low-emissivity surfaces and comparison of measured values with calculated values according to the standardized procedures. The beginning for determination of the thermal resistance of air cavity was to conduct several experimental measurements by Hot Box method using heat flow meter. The results show good agreement between measured and calculated data.

Abstract: Aim of this paper is to show modern lightweight structures based on tensegrity systems. Principles of tensegrity structures and cable domes are shown. Last part of this paper is demonstrated how to join simple tensegrity prisms to tensegrity slabs. These structures are very interesting from architectonical point of view, they are made from fully recyclable material – steel and consumption of material is very low. Tensegrity structures have a great potential of the development of modern civil engineering.

Abstract: Currently, an increasing emphasis is being placed on the properties of walling systems and efforts are evidently being made to improve the aesthetic look of structures. Vented facade systems with bonded joints are a viable option. Nowadays, the vast majority of such facades utilise mechanical joints. However, facades with bonded joints are more than simply a convenient alternative. The following article, where the potential use of bonded joints in practice is investigated via experimental measurements, deals with this technology in more detail. The presented results are taken from a series of tests which conform to the requirements of relevant technical standards, particularly with regard to the test method. This article deals with the issues connected with testing the most critical element in the whole system – the bonded joint. For this purpose, “Cetris” cement-bonded particleboard was selected for use as cladding material, and a substructure made from aluminium alloy was chosen. Five types of adhesive were selected in order to find the most suitable bonding material. During the testing procedures, the suitability of the selected adhesives for the chosen combination of materials was tested, as was the assumption that the use of the most expensive sealant does not always provide the best results.

Abstract: This paper deals with the investigation of the interdependence between the flow resistance at elevated temperatures for reinforced bitumen sheets and softening points of bitumen matter softening point in these reinforced bitumen sheets. Reinforced bitumen sheets, which are used for waterproofing isolation of concrete bridge decks, were selected as the samples from various manufacturers. In practice, the mentioned dependency is often cited, but not explicitly documented.

Abstract: This article is focused on the development and efficient application of the vegetative-retention layer for pitched turf roofs with average inclination of 25°. Developed material is composed of the recycled polyester fiber mat with clusters of the same milled recyclable waste without added chemical binders. Important part of the considering evaluation is the consecutive optimization for prospective development of the pursued layer especially focused on the selected density, thickness and roughness of the fiber mat surface.