The floor system structure HURDIS is composed of a steel beam, of floor ceramic elements and of concrete. There are materials with different behavior in fire exposition. The paper deals with the analysis of the behavior of individual elements of floor structures affected by high temperatures. Knowledge is applied to the example of the assessment of the floor structure of the storehouses damaged by fire.
Checking the inner shell of tunnels during the construction phase as well as of existing tunnels is importand for their safe operation. Various non-destructive methods have been developed for this, which allow the control check to be carried out with experiences which were obtained using the new device, pased on an ultrasonic pulse echo method.
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.
The aim of this article is to compare 3D numerical models of traditional timber joint. Numerical model of the subjected carpentry joint includes material nonlinearities. Material model of wood presume elasto-plastic behaviour and has orthotropic – transversal isotropic property. The finite-element meshes introduced herein differ one from other by element type and their quantity applied, type of mapping and local density of mesh. Number of nodes and elements, calculation convergence speed, FEM solution exactness, symmetry and mapping of elements are observed.
Building materials contains natural radionuclides, which comes from the earth's crust. In using secondary energy products as raw materials for production of building materials can increase the content natural radionuclides of products. This study focused on practical verification procedures proposed of radiation protection to optimize radioactivity of building materials. It measured the content of natural radionuclides in feedstocks and in final concrete mixtures. Measured values of natural radionuclides of concretes were compared with theoretical calculations.
This thesis deals with the water vapor permeability of wood for the most commonly used types of wood for construction work - Norway spruce (Picea Abies). Diffusion of water vapor is solved according to the density of the material, which varies depending on climatic conditions tree growth. These different conditions are in the Czech Republic mainly characterized by different altitude growing zones. Water vapor permeability is solved in the thesis by a method of measuring the diffusion resistance of materials. Specifically, the method of wet cup and dry cup, which is carried out using EN ISO 12572 knowledge and advices of previous researchers of that method. The results were compared with values reported in the Czech standard and later used for construction project of the typical timbered buildings with respect to contemporary legislation.
Presented text discusses the use of RPAS (Remotely Piloted Aerial System) in the building industry and heritage preservation. It provides information of various case studies and shows examples. For the purposes of building industry and technological area monitoring multicopter systems are mainly used. They have more complex control, but they can be successfully navigated in very low heights and low speeds around and above the object. Safe handling and ensuring the area after agreement with the owner or facility manager is crucial for their use.
Presented text discusses RPAS (Remotely Piloted Aerial System) in terms of history, legislation and its possible use especially in the civil sector. RPAS, often called UAV / UAS or “drones” in slang are a phenomenon of recent years. They present modern and popular technology that has undergone an unprecedented boom thanks to miniaturization of electronics, control and navigation equipment, high-performance battery development as well as individual components now available for affordable prices. Safe manipulation and current limits of applicability are indispensable and must be taken into account.
The paper describes a system of FBG (Fiber Bragg Grating) sensors and their integration into the beams of glued laminated timber for continuous monitoring and diagnostics of mechanical stress in building structures. The possibility of gluing the optical fibers into the timber structure and influence on manufacturing process of glued laminated timber on the glued fibers is studied. Laboratory tests including mechanical loading of examined samples were carried out to verify the correct operation of the sensors. Based on the measurement, a timber beam with embedded FBG sensors for the monitoring of the real construction have been manufactured.
The world exhibition EXPO 2015 proved from the creative and useful perspective that wood is a promising building material. We could see the use of wood on a number of exhibition objects representing countries from around the world. Even in the recent past that was not quite realistic. This was enabled by technological advances which created conditions for the implementation of bold ideas of architects associated with this renewable raw material. Along with the exhibition buildings, wood was used for the service utilities which provided comprehensive facilities of the exhibition grounds. In addition to wood, other natural materials such as rattan, bamboo and natural fibres were applied in some exhibition halls.
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.
The study is focused on evaluation of titanium dioxide nanoparticles (N-TiO2) impact on photocatalytic properties of concrete surface. Specimens made from ordinary white cement with no TiO2 particles, specimens made from commercially available photocatalytic cement and specimens made from white cement covered with polyvinyl alcohol (PVA) nanotextile containing N-TiO2 were compared with respect to their ability to decompose rhodamine B dye when exposed to direct UV radiation. PVA nanotextile was prepared by electrospinning method. The solution exploiting the nanotextile was not found to be prospective in this phase of the research. However, the method of preparation of enriched nanotextiles as well as their application on the surface of concrete elements was tried and can be adjusted for different purposes.
The paper will describe the technical requirements for the choice of the material for the steel structures and bridges. They are specified by the steel structures designer in the different deign stages. However, the tender design is the stage, where the full material specification should be given. The paper will be divided to several parts, that will describe all specification for the design, testing and checking of material.
