This paper studies the possibility of usage of the guar gum and its derivatives as admixtures for aerial lime-based mortars. The influence on the properties of mortars was studied on the aerial lime–based mortars prepared with quartz fine grained sand and doses of admixtures ranging between 0,5 and 10 ‰. The hardened bulk densities, flexural and compressive strength, carbonation rate, workability though flow table test and air content in fresh mortar were studied. The addition of the hydroxypropyl guar (HPG) lowered the bulk density (due to an air intake), improved workability, slightly increased the strength and slowed carbonation rate. The addition of carboxymethylhydroxypropyl guar (CMHPG) does not impact the bulk density and air content in the fresh mortar, the strengths were increased similarly to HPG: it does not impact carbonation rate significantly, so the long term strengths were comparative with the HPG. The pure guaran was found not to be beneficial for the lime mortars.

Wood and the materials on its basis fulfil the requirements of an ever-evolving and accelerating society. In addition to naturally grown wood, wood-based materials are frequently used as a basic material for production of furniture and for building constructions as well. Looking at changes in waste management, a significant shift from the waste to the circular economy can be observed. The valuable raw materials are kept in the production cycle instead of landfilling or burning. Wood and wooden products can be efficiently separated in waste management, reused and recycled. The so-called wood waste – old furniture, wooden pallets, window and door frames, demolition wood, used lumber, bark and other wood residues can be reused in particleboard production. Particle board manufacturers in the Czech Republic have adopted progressive waste management and currently use 60% of recycled wood into particle boards. A completed life cycle analysis (LCA) of OSB demonstrates that replacing of 50% of natural fibres with recycled wood has significant environmental benefits. The objective is to push furthermore on effective legislation to promote waste material utilization and thus lead to a more sophisticated waste wood collecting.

Wood and the materials on its basis fulfil the requirements of an ever-evolving and accelerating society. In addition to naturally grown wood, wood-based materials are frequently used as a basic material for production of furniture and for building constructions as well. Looking at changes in waste management, a significant shift from the waste to the circular economy can be observed. The valuable raw materials are kept in the production cycle instead of landfilling or burning. Wood and wooden products can be efficiently separated in waste management, reused and recycled. The so-called wood waste – old furniture, wooden pallets, window and door frames, demolition wood, used lumber, bark and other wood residues can be reused in particleboard production. Particle board manufacturers in the Czech Republic have adopted progressive waste management and currently use 60% of recycled wood into particle boards. A completed life cycle analysis (LCA) of OSB demonstrates that replacing of 50% of natural fibres with recycled wood has significant environmental benefits. The objective is to push furthermore on effective legislation to promote waste material utilization and thus lead to a more sophisticated waste wood collecting.

The article is devoted to extraction of some mode-shapes from measured data during the operational state. The measured bridge is in Bratislava and connects two city districts: The Old Town and the Petrzalka district. The structure is an asymmetric cable-stayed steel bridge with an orthotropic 2-box beam supported in one plane by cables from an inclined pylon. The bridge was measured twice, firstly in 2016 and secondly in 2017. Ambient vibration data were acquired during the measurements. The FEM model has been prepared before the measurements. Some mode-shapes were identified from the data and then compared to the calculated ones.

Wood and the materials on its basis fulfil the requirements of an ever-evolving and accelerating society. In addition to naturally grown wood, wood-based materials are frequently used as a basic material for production of furniture and for building constructions as well. Looking at changes in waste management, a significant shift from the waste to the circular economy can be observed. The valuable raw materials are kept in the production cycle instead of landfilling or burning. Wood and wooden products can be efficiently separated in waste management, reused and recycled. The so-called wood waste – old furniture, wooden pallets, window and door frames, demolition wood, used lumber, bark and other wood residues can be reused in particleboard production. Particle board manufacturers in the Czech Republic have adopted progressive waste management and currently use 60% of recycled wood into particle boards. A completed life cycle analysis (LCA) of OSB demonstrates that replacing of 50% of natural fibres with recycled wood has significant environmental benefits. The objective is to push furthermore on effective legislation to promote waste material utilization and thus lead to a more sophisticated waste wood collecting.

The paper deals with the experimental analysis aimed at function verification of fiber optic sensors (Fiber Bragg Gratings). The sensors are used for mechanical stress measurement in wooden load-bearing structures. Glued laminated timber beam with built-in fiber optic sensor system was mechanically loaded during two bending tests. The data obtained using the fiber optic sensors were compared with the results of reference measurement method and analytical calculation.

Diagnostics of building structures are used in non-destructive and destructive methods for evaluation of selected properties of building materials. Structural elements but also selected parts are assessed. Ultrasonic method, which is among the non-destructive testing methods, is being used for the diagnosis of concrete and steel structures for many years. The paper presents possibilities of carrying out inspections of selected elements of steel structures.

Sintering activity (dependence of porosity, flexural strength and firing shrinkage on the firing temperature) of feldspar dust (Casial) which is generated during the milling of potassium feldspar in Halamky quarry was determined. Potassium industrially milled feldspar Z75K13 as a reference material with similar granulometry and mineralogical composition with Casial was used for comparison. More intensive sintering activity showed dry pressed samples based on Casial in comparison with feldspar Z75K13 (about 30 °C lower sintering temperature – 1180 °C). Casial created red body after firing thanks to higher content of Fe₂O₃.

The magnitude of the load on the walls of tall wooden constructions can be assembled according to the existing standards according to the valid combination equations in several ways. There are differences between the results. Determining the appropriate procedure for determining vertical strength from construction in different parts of building preparation and comparing it with other options is the subject of this paper.

Within this work possibility of using four kinds of waste glass as a replacement for the commonly used filler, silica sand DORSILIT, to epoxy based polymer concrete (PC) is experimentally verified. Determination of compressive and flexural strength, chemical resistance and thermal resistance is examined in order to find out if PC containing waste glass as filler can be used for rehabilitation of concrete structures. Even based on the results of the tests it will be assessed whether it is possible replace DORSILIT by waste glass.

There are applications of refractory concretes for places where these are exposed to corrosive environments. This text deals with both description the corrosive effects and methodology of their testing. One of the most important properties of materials, affecting the chemical corrosion resistance, is their density. The second part of this text is focused on testing the refractory concretes which are currently used for applications. The aggregates were tested for the resistance to sulfuric acid.

Adding structural fibres into concrete has an impact, both positive and negative, on the long-term durability of concrete. Polymer fibres do not resist shrinkage of the concrete, steel fibres, on the other hand, create a tough skeleton preventing deformation. Porous structure of fibre concretes exposed for a long time in the environment of CO₂ is estimated using the method of determining the coefficient of diffusion resistence and the method of determining the capillary hight. Comparison of measured capillary hight and diffusion coefficient of fibreconcrete samples bring the knowledge, that close correlation between both quantities does not exist, due to the physical difference between determination of both quantities.

With strengthening of damaged concrete linear elements have been engaged since 2003. It is a co – ÚSTARCH SAS Bratislava, FCE University of Zilina, STU Bratislava. Repaired the damaged components – new the coupling plate with reinforced contact, the coupling plate without reinforcement – replacing the geometrical condition of contact. The use of GFRP panels. The effect of the time factor on both the MS.

The detail of the chimney system passage is one of the possible details, from a fire point of view, that occurred due to the installation of new chimney systems in to the construction of the building. The chimney system passing through the combustible structure is one of the most dangerous details in the building, from a fire safety point of view, and as practice shows, is often very underestimated. An appropriate solution for the chimney passage requires the knowledge and correct design, as well as the realization and consequently correct use of the thermal appliance and the chimney system. The article deals with passage according to the requirements of the national standards for fire segments and design according to STN EN for chimneys.

The text describes why and under what conditions the use of beech wood in building structures. Given the legislative and experimental requirements for verification of properties of beech sorting into classes of forts "D". Evaluation of the quality beech wood over the strength of the reliable design, production technology class predictive level as well as the durability of wooden building elements.

Article deals with finding of physical and mechanical properties of timber at various moisture and it also verifies addictions of single properties on moisture content of timber. In experimental part of this thesis, the density, the dimensional and volumetric swelling and the compressive strength parallel to fibre will be determined on test samples. After evaluating all the tests, the graphs of these parameters depend on various samples of wood moisture determined by weight will be created.

Tobermorite is the main mineral compound of AAC. It increases its mechanical properties. There needs to be done research of influence of type of silica components on the mineralogical compound of AAC. In the presence study, we examine the usage of nature and artificial silicious materials. Closure of the study will be design of the optimal raw material composition, also hydrothermal treatment of autoclaved aerated concrete.

The article describes the beginnings of the use of the fly ash mixture for the production of concrete in the Czech Republic, its application on important buildings (Prague subway, Nuclear power plant Temelín) and impacts on the production technology.

In December of year 2016 has been finished the extensive reconstruction of the multi-family house built in the thirties of last century, located in the district Žabovřesky of the city Brno. Investor with architect desired the modern appearance of interior and facade of the house, which involved a number of difficult renovations and new structures that had to be consulted with structure engineer. The significant steps of the reconstruction of the multi-family house are described in detail in this contribution.

In many practical cases it is important to know the actual value of tensile forces in prestressed elements of civil engineering structures. Main conclusions from experiments which were carried out within verification process and in situ application of the new method for an experimental estimation of the tensile force are described in the paper. The method is suitable for new structures and especially for existing ones.