The addition of structural fibres to concrete has a positive and negative impact on the long-term life of concrete. Polymer fibres, given their low flexibility module, do not always help the concrete to sustain its diverse deformations. Steel fibres on the other side create a hard skeleton to prevent varied deformation, but with the possibility of negative separation of cement paste from fibres. The state of the pore structure of fibre concrete exposed over a long period of time in the CO₂ environment can be detected using the method of determining the diffuse resistance coefficient and alternatively the method of determining the capillary elevation. During the process of long-term carbonation of fibre concrete, significant changes occur in the observed values of both physical quantities -- that is, the diffuse resistance coefficient and capillary elevation.

From the point of view of sustainable development in construction, the possibility of using easily renewable raw materials for the production of advanced thermal insulation materials currently represents an interesting way to effectively reduce the energy consumption of buildings. Insulators with ever-increasing thicknesses are being utilised in buildings; the use of these raw materials allows for the insulators’ production without the need for a substantial increase in CO₂ emissions and energy consumption.
Natural fibres generally display very low thermal conductivity. Despite their relatively great thickness (in the case of technical fibres) these fibres are porous, and upon reducing pressure they show significant loss of thermal conductivity. Remarkably, it is the same in the case of materials based on glass fibres, which are used industrially in the production of vacuum insulators. When using natural materials as thermal insulators there is a common problem with their high sensitivity to humidity and consequent degradation of thermal insulating properties upon increasing their water content. In the case of using natural fibres for the production of vacuum insulators, these fibres are protected against humidity by a barrier foil that creates a vacuum insulation panel (moreover, the panel also always contains an active dryer), this is why their use in this field is so interesting.

Floor construction is assessed within the thermal field by the heat transfer coefficient and surface temperatures, and in the acoustic field particularly from the point of view of airborne and impact soundproofing. When using ultra-light concrete for the construction of flooring there are unique parameters to consider. Within the contribution, the development occurred of an ultra-light concrete daub that achieved this minimal weight due to an aggregate product based on foam glass. This ultra-light concrete displays a very good ratio of mechanical performance to thermal insulation properties. As a result of these excellent thermal insulation properties, and the design of a concrete daub without joints, the formation of thermal bridges in floor construction can be eliminated.

The article pays attention to the importance of daylight and sun exposure of apartments for public health. The daylight of apartments must be given the same attention as the daylight of workplaces and schools. The way in which the daylight factor D_w (%) of the exterior window plane was introduced into the Czech technical standardization as a criterion is described. The results of a study regarding daylight of living rooms in connection with the limit values of this factor and in connection with the so-called distance angle and window area determined as 1/10 of the floor area of the living room are presented.

Together with the professional journal Podlahy, we have prepared a new series, where the authors get acquainted with the basic standard ČSN 74 4505 Podlahy - Common provisions and subsequently with other standards that are important for the floor area, and also respond to comments from opponents and reviewers. The first part of the series describes the most important provisions of ČSN 74 4505 in an annotated form.

Contractors tend to ignore design solutions to reduce the cost of construction. Change of materials, absence of building elements, adjustment of layer composition, application of cheaper alternatives – these are common situations in construction practice. In certain cases, these modifications are without consequences, but in such a situation it is necessary, among other things, to take into account the laws of physics. This article deals with the case in which the structure was replaced – instead of the reinforced concrete ceiling slab, the contractor chose a wooden structure. Wood has significantly different properties than reinforced concrete, so it is necessary to take into account several aspects such as statis, thermo-technical properties and last but not least – with whitch this article deals with – moisture conditions in the structure. The relationship of wood and moisture is specific, the article assesses a specific case of such a structure, lists the possible consequences and finally suggests the most appropriate solution – adjusting the composition of this particular ceiling structure to meet the requirements.

This paper will focus on the question of how we can work with brownfields and it will deal with tools that enable the revitalization and rehabilitation projects in the area. Tools can be divided, for example in terms of spatial planning and urban design, from an environmental perspective, from the perspective of cultural heritage protection and from the perspective of investment opportunities. The result is that the issue of brownfields is handled by numerous institutions and instruments. The aim of this paper is to identify, classify and analyze these instruments. Paper will study instruments from other countries with long-term experience with this issue (eg. France, Great Britain, USA, Germany, Denmark) and analyse the feasibility of their implementation in the Czech Republic and their contribution. Because this theme is a very complex one, this paper is mainly focused on urban planning tools, economic tools (incentive and penalty) and building tools (designed to uphold the intentions of the municipality or the state by building mainly transport and technical infrastructure).

The Architecture and Urban Planning Committee of Protected Landscape Areas in Central Bohemia Region has to deal with low-suitable new family houses architecture design very often. The recommendations for buildings were written to preserve typical architecture form. Due to the passive standards coming be ordinary used in family house design, Administration of the Krivoklatsko PLA initiated the cooperation with Faculty of Civil Engineering CTU in Prague to try find new design for Krivoklatsko PLA. Architecture and Building Engineering students worked out design of new family houses as their Bachelor projects. The goal of this paper is to present student projects as an inspiration for builders and evaluate the usage of new shapes and materials in the design suitability context.

The present paper deals with the measurement of the thickness of the coating on wood using the ultrasonic method, which is based on the measurement of the ultrasonic pulse passage time through the layer. One of the biggest advantages of this method is non-destructive measurement, which allows online quality control during operation, eg when checking paint thickness on window or door frames. During the experiment, the deviations of the coating thickness measured by the destructive and non-destructive method were recorded, however, these deviations were in most cases smaller than the inaccuracy of the optical microscope measurements. The results clearly showed that the accuracy of the described method is sufficient and can therefore be used to measure the thickness of the coating on porous and diamagnetic materials such as wood.

White tanks are structures which, in addition to the load-bearing function, must also have the function of watertightness. Watertight of the concrete is ensured by adherence to design, production and technological measures. The width of the early-age cracks that former in the structure is controlled by the reinforcement. During construction, however, joints (expansion, construction and control) are created in the structure, which must also be watertight. The joints are the most sensitive place of the white tank and therefore the most leaks are created at the point of the joints. The correct choice of the joint sealing system is the basis for the design of the watertight joint. The paper deals with the description of various joint seal and pipes through of the white tank.

The mass construction of apartment buildings using the technology of large-format prefabricated prefabricated elements in the former Czechoslovakia took about 40 years. The lifetime of these buildings is approaching their planned value. A common problem of prefabricated buildings is the creation of new openings in load-bearing structures without prior expert appreciation. The important details of the joints of the support elements have changed not only between the individual assemblies, but also during the development of the particular assembly. The article describes some problems of load-bearing structures of prefabricated buildings, which designers have to consider in their assessment.

The construction of precast hous consists of prefabricated concrete walls and floor slabs. These elements through joints form rigid spatial (so-called box) load-bearing system. The prefbricated elements of this system were designed for certain layout and static possibilities of the panel system. All additional interventions in the load-bearing structure must be thoroughly investigated. If necessary, it is also necessary to propose a suitable way of strengthening the weakened parts of the load-bearing system.

This article is focused on current situation in preparation of new generation of European standard for design of concrete structures prEN 1992-1-1. This article deals with main features and development in design principles involved in new standard. In these days there is available the 4th draft of standard for comments of national authorities and experts. The final draft of prEN 1992-1-1 should be finished this year (2020) and provided to formal vote in CEN.