Academic literature on the topic 'Požární odolnost betonu'

The thesis is focused on the current issues of concrete resistance to high temperatures. The theoretical part has been processed the changes taking place in the individual components of concrete and changes affecting the physical - mechanical properties of concrete and color-changing effects manifesting high. In the experimental part of the load was, carried concrete test samples to a temperature of 400 ° C, 600 ° C and 800 ° C. After the thermal load, has been on test samples tested changes in physico - mechanical properties, especially concrete compressive strength, water absorption but also a visual assessment of the concrete surface

This dissertation deals with the study of durability and degradation repair mortars for reinforced concrete structures. In its theoretical part, there are the research findings on the behavior of repair mortars exposed to corrosive environments with different exposure time and selected high temperatures. Processes occurring in repair mortars during their loading at high temperatures or when exposed to chemically aggressive environments are described, We can find recipes designed for cementitious binder based with a specific replacement using slag or fly ash in its practical part. The object of the research was to determine the durability of the proposed repair mortars, and determine their suitability for use on concrete structures, which may be exposed to a synergistic effect of chemically aggressive environments with high temperatures simulating fire.

This master‘s thesis is focused on the study of the behavior of cement concrete at high temperatures with a focus on monitoring the impact of aggregate and cement type. This work describes the processes in aggregates and cement matrix at high temperatures. The theoretical part describes the selestion of a suitable aggregate and cement for the surroundings with potential exposure to high temperatures. In the experimental part is given design of composition of a concrete with two types of aggregates and four cements. It has been suggested 8 recipes. Changes were observed densities, compressive strength and tensile strength in bending, calculate the velocity of propagation of waves with ultrasonic pulsed method. Also evaluated the appearance of the surface samples after thermal load – cracks on the surface and measure the maximum crack width.

This diploma thesis is focused on behavior of cement concrete at high temperatures. The theoretical part describes processes, which take place in concrete at thermal loading and effect of this thermal load to mechanical and physical properties of concrete. Also there was described recommendation for testing physical and mechanical of concrete at high temperatures according to RILEM TC. In experimental part mixes were made with greywacke aggregate, amphibolite aggregate and with the addition of polypropylene fibers or cellulose fibers. In these mixes was determined the effect of high temperatures on the density of concrete, compressive strength of concrete and thermal strain of concrete. Further there was tested addition of 2 kg/m3 polypropylene fibers to concrete with basalt aggregate and siliceous aggregate and influence of these fibers to density of concrete, compressive strength of concrete and dynamic modulus of elasticity.

Diploma thesis summarizes knowlegde related to the behavior of structures and material in the fire, focusing mainly on concrete and reinforced concrete structures. It deals with the design and implementation of diagnostic work of Building no. 103 in complex Svit Zlín affected by a large fire. There are presented evaluation of laboratory experiments of samples and static analysis.