This thesis is focused on the description and evaluation of the status of existing reinforced concrete and of the prefabricated overhanging structures. The first part describes the solution overhanging structures, followed by a description of selected diagnostic methods for determining the properties of concrete in the structure and to determine the degree and extent concrete reinforcement. The main objective is to determine the status of overhanging structures on the case static analysis and critical points of the support structure for the purpose of the planned revitalization of the object.

The diploma thesis deals with development of high resistant composite, which brings its properties closer to the melted basalt products. This fact will allow substitution of basalt elements in hostile chemical environment by newly developed material and completes its product line. High resistant composite also consists of secondary raw material in highest possible amount. Material that is being evolved carries high strength, abrasion resistance and is also resistable in hostile chemical environment.

In der vorliegenden Untersuchung wurden Messungen der Veränderungen der Ultraschallgeschwindigkeit in Betonproben verwendet, um die Entwicklung der Schädigung in Betonen der Festigkeitsklassen C80/C95 und C120/135 während Ermüdungsversuchen unter verschiedenen Beanspruchungsniveaus zu quantifizieren. Die Ergebnisse zeigten die Abhängigkeit der Entwicklung von Ermüdungsschäden von den Belastungsbedingungen und den Betoneigenschaften. Eine der wichtigsten Schlussfolgerungen aus den hier vorgestellten Forschungsergebnissen ist, dass die Druckfestigkeit des Betons allein keinen Hinweis darauf gibt, ob ein Beton unter Ermüdungsbeanspruchung ein abruptes Versagen oder ein progressives und angekündigtes Versagensverhalten zeigt.

Self-consolidating concrete (SCC) has wide use for placement in congested reinforced concrete structures in recent years. SCC represents one of the most outstanding advances in concrete technology during the last two decades. In the current work a great deal of cognizance pertaining to mechanical properties of SCC and comparison of fracture characteristics of notched and unnotched beams of plain concrete as well as using acoustic emission to understand the localization of crack patterns at different stages has been done. An artificial neural network (ANN) is proposed to predict the 28day compressive strength of a normal and high strength of SCC and HPC with high volume fly ash. The ANN is trained by the data available in literature on normal volume fly ash because data on SCC with high volume fly ash is not available in sufficient quantity. Fracture characteristics of notched and unnotched beams of plain self consolidating concrete using acoustic emission to understand the localization of crack patterns at different stages has been done. Considering this as a platform, further analysis has been done using moment tensor analysis as a new notion to evaluate fracture characteristics in terms of crack orientation, direction of crack propagation at nano and micro levels. Analysis of B-value (b-value based on energy) is also carried out, and this has introduced to a new idea of carrying out the analysis on the basis of energy which gives a clear picture of results when compared with the analysis carried out using amplitudes. Further a new concept is introduced to analyze crack smaller than micro (could be hepto cracks) in solid materials. Each crack formation corresponds to an AE event and is processed and analyzed for crack orientation, crack volume at hepto and micro levels using moment tensor analysis based on energy. Cracks which are tinier than microcracks (could be hepto), are formed in large numbers at very early stages of loading prior to peak load. The volume of hepto and micro cracks is difficult to measure physically, but could be characterized using AE data in moment tensor analysis based on energy. It is conjectured that the ratio of the volume of hepto to that of micro could reach a critical value which could be an indicator of onset of microcracks after the formation of hepto cracks.