This paper discusses the practical use of microwave technology in construction practice. Opinions on the use of EMW devices are not only among the general public quite different. From boundless praise, to the uncritical condemnation. The reason for this situation is the lack of awareness of experts and the public about what is and what is not possible to expect from this technology.The article conclusions which we reached on the basis of experiments conducted at the Faculty of Civil Engineering Brno and subsequently verified measurements in field practice. The aim is to provide basic information about how to use microwave technology. Their benefits but also the risks that this technology brings along.
1 comment, 04.04.2017 15:22
The article deals with hot-air treatment of a historically valuable Rožnov town office, built in 1770, which was transported to the Wallachian Open Air Museum in Rožnov pod Radhoštěm in 1924 as the first building of the currently extensive premises of this national cultural heritage. The method of wooden structure hot-air treatment was used for the first time in the territory of the Czech Republic in 2010. It has been used in western European countries (especially Denmark and Germany) approximately since 1930. This comprehensive method is governed by the German standard DIN 68 800 – Part 4  and it is especially used for historically valuable buildings where emphasis is put on the preservation of the original wooden structure attacked by wood-destroying insects, usually of the long-horn beetle family (Cerambycidae) oranobium beetle family (Anobiidae). The goal of the article is to explain the hot-air treatment method to professional public using an example of one of implementations.
Water vapour permeability is one of significant material properties. The value of water vapour resistance factor is necessary to know to be able to rehabilitate structures, mainly after floods. One thing is essential – to know what are the values of water vapour resistance factor of the used material to know how long the structure will take to be dried and users can come back to live there.
Article discusses possible ways of shallow foundation during construkction and reconstrukction of objects placed in gap sites and other nearby buildings.
For more than a year, a nearly zero-energy standard has applied to certain buildings. In the Czech environment, specific technical parameters for such buildings have been known for three years. And for over six years, the Directive on energy performance of buildings has been in force, imposing the obligation upon EU member states to introduce this standard.
Nevertheless, it seems that for many experts, including those in the field of energy, this term is still quite unclear. Many imagine buildings coated with photovoltaic modules from the ground to the roof, buildings which are better than passive ones or buildings which are self-sufficient, i.e. completely independent of public energy networks. Given the fact that the concept of a nearly zero energy building is very distant from such notions, and because this standard will soon become obligatory for all buildings, including small family houses, let's have a look at what a nearly zero-energy building really is.
The article is dedicated to the diagnosis of classical reinforced concrete structure in the spirit of “Bata architecture” built in the 30s of the 20th century. The preliminary inspection suspected presence of aluminous cement in concrete, which was subsequently confirmed by the detailed diagnosis.
The removal of unwanted material from the surface of historical artefacts is one of the most important and also the most delicate operations in the restoration of cultural heritage. In the Center for innovations in the field of nanomaterials and nanotechnologies a novel design concept of the cleaning microemulsions was developed based on a combination of the two functions, implemented by two components, namely a micellar solution or microemulsion of nonionic surfactants with the addition of co-surfactants and the specific solvents, which are selected according to the respective substances to be removed. The patented cleaning compositions can very effectively and selectively remove coatings of many substances important for the restoration practice, such as waxes, resins (e.g, Damara), paraffins, oils, water acrylate dispersions, hydrophobization coatings (both monomeric and polymeric) etc. Besides the efficient cleaning, the developed procedures have wider applications, such as in a new method of the hydrophobization of sandstone and limestone materials with a thin hydrophilic surface layer, which has been certified by the Ministry of Culture of the Czech Republic.
Non-aqueous dispersions of nanoparticles of calcium hydroxide and magnesium are principally suitable means for the consolidation of wall paintings and limestone materials because they are compatible with the material of historical artefacts. They are also suitable for the deacidification of paper and wood. In the Center for innovations in the field of nanomaterials and nanotechnologies procedures were developed which provide nanoparticles of calcium hydroxide and magnesium ranging in size from about 10 nm to about 200 nm. The procedures are relatively experimentally challenging and put them into practice will require further technological research. Thanks to the good stability of the dispersion a sufficiently long shelf life is ensured and premature aggregation on the surface or just below the surface of treated materials is prevented. There are several alternative methods of the consolidation stone, as exemplified by the use of alkoxides of calcium or magnesium. In converting the alkoxide to calcium carbonate, the sole by-product is alcohol, which naturally evaporates from the stone.
The article describes selected topics from historical buildings fire protection methodology. Covered topics are fireproof coatings, building division into fire compartments and attic and roof.
Concrete structures of historical buildings and their evaluation based on the non-destructive methods29.8.2016 | Ing. Ondřej Anton, Ph.D., Ing. Petr Cikrle, Ph.D., VUT Brno, Ústav stavebního zkušebnictví
During the assessment of existing structures of monuments made from reinforced concrete is always necessary to verify the properties of concrete and placement of reinforcement. The paper deals with testing of concrete by non-destructive methods – especially by hardness test method and ultrasonic method. For testing of historical structures seems to be the most suitable ultrasonic method.
Within the reconstruction of town hall premises, the authorities of a district town decided to rebuild existing ramshackle group house radically. The house is located in a historic area of the city and therefore some parts of the house, namely the medieval cellars and street front, are listed. In addition, the adaptation of the underground spaces, facades and gable walls was necessary, too. In the course of designing process and also during the reconstruction works, the drawings had to be repeatedly revised, partly quite fundamentally.
Floor area in living spaces with slanting ceilings has an ambiguous interpretion in czech national regulations. It has an effect on a building approval process and this article describes how to determine this area in both architecture and civil enginnering.
1 comment, 21.06.2016 11:21
The article introduces the new method “Lapped Scarf Joints for Historical Structures Repairs” that deals with design of the lapped scarf joint suitable for the reconstruction of valuable historical timber structures, with help of making the prosthesis for the damaged parts of the beams. The method is a result of the four-year research project supported by the Czech Ministry of Culture within NAKI program. Institute of Theoretical and Applied Mechanics AS CR, Faculty of Civil Engineering CTU and Faculty of Forestry and Wood Technology of Mendel University participated in the research.
Agriculture and agricultural buildings ever has developed for centuries. In the past these buildings closely followed the living area. Later, for hygienic reasons, they were moved on the edge of residental areas. During the establishment of agricultural cooperatives the distance between farm buildings and residential areas started to increase. This development of buffer zones of agricultural buildings has had a large and indelible impact on the shape of our landscape.
The article is based on experiences with interesting fire safety solutions in historical buildings in the Czech Republic and abroad. It shows that fire safety precautions are possible almost everywhere. They are usually quite simple and affordable and without fear of aesthetical damage as well.
The paper describes the possibility of using fire engineering methods to ensure the safety of cultural monuments. Character of cultural heritage and the effort to preserve their historical value, is the cause of conflict situations in their evaluation in terms of fire safety. The case study of the picture gallery demonstrates some of the options of models of fire which are possible tools in solutions different from standards. The use of fire engineering methods is commented with relation to subjects usually participating in fire engineering applications.
The paper presents an overview of preservation methods based on professional, expert assessment and research activity of the Thermal Preservation Methodological Department. It reflects the suitability and usability of available methods for wooden elements of respective type of structure. The methods are represented according to currently available and applied preservation methods. The methods use thermal energy, namely the hot-air sterilisation of wood and microwave technologies. The presented paper specifies conditions under which the methods shall be used so that their application contributes to more efficient protection of the heritage fund. The field of biotic harmful elements includes wood-destroying insects and fungi with special regard to dry rot fungus (Serpula lacrymans).
The article deals with operation of historical buildings from the facility management view. Facility management of historical buildings in the article refers to buildings that are treated according to the czech law no. 20/1987. These buildings are cultural sights.
The paper presents a methodological procedure and results of acoustic detection of wood-destroying insect larvae in the buildings of the Wallachian Open Air Museum in Rožnov pod Radhoštěm. Using the Acoustic Pack acoustic system, the activity was monitored at 112 positions of wooden trusses of framing on the house of Prlov and Rožnov Town Hall as structures considered for the performance of a preservation measure. Based on the obtained results, the actual status of active infestation of wooden elements was defined with the graphic output of activity and sound records which will be used for designing efficient preservation of the structures.
In early September, the administration building Aviatica was inaugurated and officially unveiled, which is the flagship of a large development in the former factory Walter in Prague. Use of abandoned industrial sites, called Brownfields has been the great theme of Planning and Development during the last few years. Vast territories with dilapidated buildings have a negative impact on their environment, in terms of the degradation of the environment, environmental stress, negative social phenomena or reduction of the economic potential of the site. These lucrative localities are connected to existing technical and transport infrastructure. The transformation has a positive impact on the surrounding areas and instead of spatial expansion of cities into the countryside is one of the ways to exploit their intrinsic potential.