Examples 9 to 15. Preface and helping data for calculation see Part 1 to 3.
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The paper will describe the technical requirements for the choice of the material for the steel structures and bridges. They are specified by the steel structures designer in the different deign stages. However, the tender design is the stage, where the full material specification should be given. The paper will be divided to several parts, that will describe all specification for the design, testing and checking of material.
Preface – Helping data (continuation): Compression design strength at an angle to the grain – Columns: buckling coefficients for solid timber and for homogeneous glued laminated timber – Stability of members: Beams subjected to bending without compression force – Tilting factors – Laterally loaded joints with dowel type fasteners.
Timber and glass are the materials that have excellent aesthetic qualities. In current architecture, glass, as well as wood, are increasingly used for the visually exposed structures. Since glass is a brittle material, various types of hybrid structures are developed. Glass in hybrid element is combined with other material (eg. concrete, timber, steel, aluminium etc.) to increase load-bearing capacity and stiffness of the element, achieve safe failure behaviour together with high level of transparency. Nowadays, several European universities and research centres deal with the glass-timber load-bearing elements. This article provides an overview of the developed hybrid timber-glass structures including an experimental analysis of adhesive timber-glass joints, which was performed at Czech Technical University in Prague.
Transparency and also smooth, glossy and reflective glass surface give special importance of this material in the contemporary architecture. Connections between two glass elements or glass pane and other part from a different material are very important issue for structural applications of glass. Moreover, there are many types of hybrid structures that combine glass and different materials to achieve safe failure behaviour and high degree of transparency at the same time. Connection of brittle glass and reinforcing material is an essential part of these structures, where composite action between two parts is beneficially ensured by a glued joint. Experimental determination of mechanical characteristics of various adhesives applied in planar connections under shear loading is a main topic of current paper.
This paper presents methods to enhance the punching shear resistance of existing flat slabs (enlargement of supported area, enhancement of flexural resistance of slab, post-installed shear reinforcement and prestressed solutions). In case of post-installed shear reinforcement, systems based on steel and CFRP are mentioned. Static, technological and economic advantages and disadvantages are analysed. Differences between the systems are mainly due to the requirement to access the upper face of the slab, resistance-decrease in case of fire and deformation capacity of the strengthened slab.
The corrosion of steel reinforcement is the most important factor in degradation of the concrete structures. The use of the new composite materials as reinforcement in concrete structures has expanded in recent years. These concrete structures are often exposed to extreme environmental loads. The fibre reinforced polymer (FRP) materials are an alternative to the steel reinforcement. It is a durable material, which has corrosion resistance, high tensile strength and low density. The manufacturers use various kinds of fibers in the FRP reinforcement, especially carbon (CFRP), glass (GFRP), aramid (AFRP) and basalt (BFRP). The present article describes the application of the FRP reinforcement as a replacement of the steel reinforcement in new structures, respectively for strengthening of existing concrete structures.
This paper proposes statistical methods for evaluation quantitative performance determinated by tests of building products for objective decision during conformity assessment / certification in a fire protection field. The procedure is applicable for other types of products, and research / development of new material products.
Concrete exposed to high temperature considerably changes its properties down to total destruction. The paper describes renovation of concrete floor damaged by a fire of a factory building. Individual steps of determination of damage of concrete floor structures caused by high temperatures are described. Structure of damaged floor was technically analyzed, redevelopment was designed and renovation works were carried out.
Research, development and testing of materials and safety features used to protect civilians and armed forces against terrorist or military attacks are more than desirable nowadays. Therefore, our work is aimed at absorption materials that can temper impact energy and shockwave energy originating in explosive blast.
Out of many materials potentially suitable for experiments, two groups of fillers were chosen – macro fillers and micro fillers – and a two component polyurethane binder. In this article, the resulting physico-mechanical characteristics are summarized: bulk density, flexural, compression and impact strength. The crucial test for determination impact energy absorption was the Split-Hopkinson pressure bar test, conducted with most samples.
Buildings which are issued to natural changes of atmospheric temperature, should be divided to parts that can act independently. If not, the structure itself will be split up according to the general laws of physics and the internal and external form and material properties of the structure. The article describes failures of expansion joints of constructions.
This article deals about tropical hardwood species used for commercial purposes. These kinds of wood have more advantages like better natural durability against bio-degradation caused by high amount of extractives and good mechanical and physical properties. But their using is also connected with some questions – ecological and economical aspects and stability of supposed properties for each delivery. Not solved problem is protection against weathering and mainly decreasing of colour changes of tropical wood surfaces in the exterior till now.
Wilful attack targeted on strategic buildings and critical infrastructure can pose significant thread to property and human lives. By modification of the material traditionally used in building industry, in particular by addition of randomly dispersed fibre reinforcement in currently most spread building material – concrete, the enhancement of the blast and ballistic resistance can be effectively achieved without high additional costs. Within the research works presented in this article, the influence of several types of fibre reinforcement on the blast resistance of the concrete panel was assessed. The results of real blast tests indicates, that incorporation of any type of fibre brings enhancement of the blast resistance of the concrete, but the level is highly affected by strength and shape characteristics of the fibre.