The paper discusses approaches to safety assessment of historic timber structures using testing of very small specimens extracted from a historic structure or by direct in-situ testing. The presented methods must to take into account conditions given by the EN 16085. They further consider environmental influences and correlations of characteristics achieved by various SDTs.
The paper shows reasons for carrying out restoration of historic wooden ceiling using “dry method” – interaction between historic wooden beams and wood-based panels. This article summarizes the process of reconstruction of historic wooden ceilings, describes the problems to be addressed and it summarizes experience with completed ceilings in Brno,Czech Republic.
The possibilities of using nanomaterials are quite broad – from increasing the hydrophobicity and photostability of surfaces, through improving the mechanical properties of traditional materials, aiding in the diagnosis and therapy of certain diseases, repairing damaged parts of the tissue, and solving problems in decontamination of the environment. Intensive research also takes place in their applications to increase the resistance of wood to wood-boring fungi and wood-destroying insects. Nanomaterials, including nanocellulose, are perspective in the field of wood fire protection, which may be important in the evolving trend of wood building construction.
The composite materials for strengthening/reinforcement a concrete has become the new construction product set up for compulsory verification pursuant to Act No. 22/1997 Coll. (č. 22/1997 Sb.) as amended by Government Ordinance No. 163/2002 Coll. (č. 163/2002 Sb.) as amended by Government Decree No. 312/2005 Coll. and No. 215/2016 Coll (č. 312/2005 Sb. a č. 215/2016 Sb.) This reinforcement exists in several different types, and accordingly, it also has significantly different properties which must be strictly respected in its use.
Despite efforts to maintain quality during the construction of reinforced concrete structures, it is relatively common for improper reinforcement to be used contradicting the project, which can lead to serious structural defects. It is then up to non-destructive testing methods to prove these defects. The key is to choose the appropriate method and device for the task.
The paper describes the technology of liquefaction and stabilization of soils that are created in the excavation works of engineering networks. Liquefied grout could be used to fill even the less accessible spaces of utility networks. For the re-use of the excavated soil in a liquefied form, is necessary its pre-treatment, which consists in stabilizing by the suitable stabilizing additive. The mixture is furthermore required the liquefaction by using a suitable liquefying additives. Suitable for stabilization and soil liquefaction it seems the use of fly ash, as is mentioned below in the paper.
The cause of moisture in the masonry could by different. By old historical buildings is the problem in absence of hydro-insulation, which was made by flat stones or clay backfill. New buildings have a lot defect by application (for example: pipes penetration, join) or wrong design of hydro-insulation, which are the point infiltration of water in to the construction. This problems are made by wrong projection of hydro-insulation in the project. The project does not reflect all influences of the water. But they are also another cases, which can happened like river floods, flood by the neighbour. In those cases it is demanding to dry the building as soon as possible, to protect the property from the mold and return the function of the building. One of the method, which is suitable for this solution is microwave dehumidification, which realize all conditions in one. This aim include also the practice example of the microwave sanitation technique, used by dehumidification masonry, and the positive results.
The definition of what is a common part of a residential building is essential especially when modifying the building structures and eliminating defects that affect both a common part and residential units. How common parts are defined affects who finances the modifications and reconstructions of such structures and parts. The definition of common parts is based on the new Civil Code (No. 89/2012 Coll.) and on the already abolished Act on Ownership of Housing (No. 72/1994 Coll.).
At present, there is growing interest in the realization of multi-storey wooden buildings. In the case of multi-storey wooden buildings, their safety, stiffness and acoustics are of key importance. The submitted paper focuses on the issue of fire safety of multi-storey wooden buildings, which is currently the subject of major discussions.
A growing environmental awareness and desire for sustainable solutions and healthy living conditions, especially in Europe, lead to an increasing demand for timber structures. High speed, excellent cut quality and accuracy of CNC processing allows an effective produce of timber structures by traditional carpentry procedures. This article responds to current problem of load bearing capacity calculations of traditional carpentry joints. This way of structural joints has not sufficient support in current standards and therefore design relies on simple empirical relationships based on experience. This paper presents the experimental and calculation methods for investigation of static behaviour and load bearing capacity of carpentry joints.
The contribution dealst with the problematics of statical defects, or more precisely with the formation of cracks in the brickwork caused by the effect of technical seismicity. It further deals with the construction principles which can be used when designing reconstruction of buildings which are located within the reach of the effect of technical seimicity. The problematics of historical buildings and conservation areas is also mentioned.
Computing models for structural behaviour and determination of traditional timber butt joints using analytical relations are presented in this paper. A component method is a base of the computing technique introduced herein. This method is usually used for steel joints design. The component method is based on dividing a joint into individual components. These are defined by partial joint component stiffness. An analytical solution includes a subsidence effect of wooden material in a close proximity of compressive loading. Analytical computation results are compared with the experimental outputs. A design procedure according to Eurocode 5 for a load capacity determination of perpendicularly loaded structural element is stated in the paper.
The article presents research into the effect of carbon nanotubes in the blended polymer-silicate matrix containing raw materials from alternative sources. The intention was testing of several variations of mixture composition at the laboratory and also extreme temperature ambient. Assessing the suitability of the matrix composition was carried out by using both basic physico-mechanical parameters and then microstructural analysis methods (on selected samples).
Utilization of fibre concrete in building structures, supported by technical standards in preparation, stimulates the development of methods for nondestructive analysis of its structure, crucial for mechanical properties, as fracture resistance under tensile loads. The paper presents an overview of available methods, based i) on image processing and ii) on measurements of electromagnetic quantities.
