The paper presents results of a study on potential reduction of CO₂ emissions of the Czech national building stock until 2075. The calculations were based on datasets provided by Chance for Buildings that modeled five different scenarios of energy savings in the Czech building stock that varied by the depth of the energy retrofitting measures and by the pace of their application. The results were compared to the carbon budget that was set in line with the objectives of the Paris agreement.

Due to the combination of electron conductivity in metals, ionic conductivity in rock environment together with bacterial activity in groundwater, and pumping of water from the well an increasing clogging occurs in the circumference of wells equipped with steel casing. This is why I do not recommend to equip wells with metallic and especially stainless steel casing. It is critical that metallic objects connecting the aerobic and anoxic zones are not used in wells equipped with electrically non-conductive casing. This particularly applies to the displacements of pumps and for the ground conductor. To suppress well clogging, it is therefore necessary to avoid connection of the ground conductor of the pump to the ground system.

The article is focused on the analysis of connections of timber elements with doweled type steel elements. The main scope of the article is to assess a load bearing capacity and stiffness of different types of doweled connections and comparison of theoretical results with results obtained from experimental tests. Subject of the research were connections composed of C24 grade solid timber elements connected with nails, screws, dowels, threaded rods and bolts. Findings and conclusions derived from the analysis of assumed connections can be used for a design and execution of doweled type connections in timber structures.

The paper is focused on the evaluation of the possibilities using the diagnosis of building objects and outcomes of the mobile 3D scanning process of existing objects and their software transformation using Building Information Modeling (BIM). Emphasis is placed on the creation of building object based on the point cloud determined by 3D mobile mapping. The main objective was to process measured data from mobile mapping, import data into the Autodesk Revit program and create a BIM model. A partial objective was to compare the resulting object originating from the point cloud to the existing project documentation. Conclusion of the paper is evaluating the process through SWOT analysis.

This work is focused on the verification of the possibility of using specially modified hazardous waste, solidification product, formed from selected secondary raw materials as solidifying agent and hazardous waste (end-product) as a filler in polymer grout joint material. Totally, two solidification technologies were verified, the first one was wet granulation of raw materials and another one was dry homogenization. It is more advantageous to use dry homogenization technology, which is economically less demanding. The possibility of using a specially modified filler was verified by the appropriate tests, and results showed that the grout joint showed high compressive strength of approximately 50 MPa, flexural strength up to about 20 MPa. Developed material can also be characterized by very good cohesion with the cast basalt.

Using the appropriate secondary raw materials, it is possible to reduce the bulk density of AAC while preservation the physical-mechanical properties, e.g. strength. This reduces the total weight of the construction and allows for wider use, for example, in the application of material to reduce the load on non-load-bearing walls or to increase floor levels. Research is focused on the use of 10%, 30% and 50% admixture of fluidized bed combustion ashes and slag in the AAC. AAC was developed in the hydrothermal conditions of the autoclave at 7 hours of isothermal soak at 190 °C. The results showed the dependence of the rheological properties on the amount of admixture of fluidized bed combustion fly and bottom ash, slag. Research has shown that the use of 10% admixture of secondary raw materials will not significantly affect the physical properties of the samples.

We can observe a bad or even a state of emergency condition of the several bridges which are today in service for more than 60 years. There were find out on the structures any serious failures such as excessive deformations, extensive cracks, corrosion of prestressing wires and the anchors, etc. One of the most important thing in the process of the existing prestressed structures reliability evaluation is to determine the current level of prestressing in concrete structure. There have been developed in the world and in our country several methods that enable predict the current level of prestressing in a structure. This paper discusses the possibilities of determining the prestressing level on an existing structure using the indirect method as (Structural response method) founded on the theoretical-experimental base. This method was applied on an example of the precast prestressed bridge girder analysis after its 60 years in service.

The effort to make labour easier is as old as mankind itself. This paper wants to point out some generally tolerated deficiencies in well equipment (casing) including some problems in the behaviour of commonly used materials in well casing.

Reports on drought in the Czech Republic, as presented in the media and in news releases of government institutions, are overstated. Natural course of climate is not accepted and data on groundwater are distorted. Nobody but ourselves should be blamed for some of the effects of “drought”, which result from a misconduct in drilling and casing installation in wells and boreholes for heat pumps as well as from anthropogenic interventions in landscape. landscape.

Feeling safe affects our daily lives, is one of the basic human needs and affects the quality of life. Security is a seemingly clear and simple field. But the question is how to distinguish the quality offered from fraudulent pretense?

An important task of the present is the preparedness of the Czech Republic for more frequent and intense drought episodes. One of the partial issues is also the evaluation of the importance of water resources protection zones in order to fulfill their function not only in the normal situation, but also in dry seasons. The paper contains the following parts: experience from the analysis of pilot areas, protection zones as an operative or preventive tool in drought, protection of yield, protection of groundwater infiltration areas, protection zones as a reflection of time of its creation, national database of protection zones, professional level of protection zone proposals, structure of risk assessment in proposals of protection zones.

The current trend of research is concerned with the multi-compartment fire dynamics – the dynamics of a fire which spreads through multiple rooms, such as a house or multiple-room flat. It is based on the results obtained from the one room fire dynamics researches, but in dealing with this cases much more variables need to be considered. This complicated process facilitates mathematical modeling and tests fires in laboratories. We bring some integrated outputs that will surely be useful for practice.

Determining a location of the fire origin is an important and integral part of the process of the fire investigation. Any new information, experience, research or method represents an improvement in this complicated area. With this knowledge, fire investigators can more confidently interpret conclusions of their work. Fire dynamic also helps them with a better understanding of fire effect and assistance them with evaluating fire patterns in affected rooms of buildings.

This paper presents utilization possibilities of micronized recycled chemically activated concrete powder. So far, these fines of waste concrete have not been used in technical practice. Combination of micro milling and chemical activation were carried out using suitable admixtures such as fly ash or slag. These showed to be one of possible ways how to reuse such materials and apply them during production of new cement binder and concrete. In this paper, microscopic analysis of thispowder was carried out. Moreover, an impact of chemical activation on resulting mechanical properties was investigated.

Compartment fires are among the most frequent and also the most dangerous ones. Accordingly, we pay special attention to these fires in terms of fire tactics. In the Czech Republic, several facilities have been created to simulate fire conditions in enclosed spaces (“flashover containers”) and the firefighters have the opportunity to prepare for potential hazards. However, can this type of fires be special in terms of fire investigations?

Building Information Modeling (BIM) is being developed in almost all construction sectors in the Czech Republic. For Quantity Takeoff (part of Cost Management, referred to as BIM 5D), this brings many opportunities and challenges associated with the need of local workflows modification in accordance to information modeling needs. This article describes how data from BIM models can be used today to cost estimates using the proposed process scheme. It also indicates what needs to be done to achieve the full utilization of the BIM method in terms of cost estimation.

Fibre-reinforced concrete is increasingly used in structures where its properties can be utilized - especially tensile and residual strength after cracking. For applications in load-bearing fibre-reinforced concrete structures, it is necessary to ensure the uniformity of the steel fibres distribution in its structure. The paper summarizes the current knowledge of fibre-reinforced concrete production and test methods, which can be used to monitor the uniformity of fibres distribution in both fresh and hardened fibre-reinforced concrete.

The present research work at primary phase deals with the development of high strength heavyweight concrete based on cementitious composite comprising alternative raw materials and two types of high density aggregates (barite and magnetite). The design of concrete is based on six mortar specimens from which concrete blocks and prisms are prepared for physical and mechanical properties tests.

Waste concrete contains a portion of non-hydrated particles within a concrete paste. Because it is a valuable material, ways how to reactivate and apply them during production of new materials are searched. The mechanical reactiovation seems to be a potential technique to achieve that. This method is based on very fine milling of waste concrete, resulting inmicronized powder. In the course of such process, unhydrated grains are uncovered. Hereby, these can be involved in future hydratation processes. In order to find the efficiency of such reactivation, the combination of two methods was employed, describing the shape and phase composition of the resulting grains. Three different kinds of waste concrete were tested, differed in their age, use, and method of production. It was found that old concrete waste with Belitic binder is the most suitable of them for the mechanical activation.