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The paper deals with evaluation of possible fatigue damage of existing steel crane structure. It is possible to use the some traditional methods to solve the problem - a concept of fatigue S-N curves (which are mainly used for designing of a new structures) or the procedures based on linear fracture mechanics utilizing the Paris-Erdogan’s law (which are suitable for estimation of remaining lifetime). For the resistance assessment the relevant data of load effects caused by cyclically loaded structure operation are necessary for both concepts. For the prediction of fatigue damage over time, calibration functions for short edge cracks were derived based on the results of the experiment, and the acceptable size of the fatigue crack in damaged structural component under analysis was determined. Using the derived relationships, a stochastic analysis of the selected element was performed and the results are discussed.

While examination of the durability of ordinary concrete mixtures is of interest of many research groups, only limited amount of information is available in terms of lightweight concrete tested under the same conditions. In this case, the durability related to the chloride ion diffusion is investigated on the relatively new type of structural lightweight concrete, which, above all, contains waste material – red ceramics sand, and artificial expanded clay coarse aggregate. Used aggregates were fully soaked before adding into the concrete mixture, so also the internal curing effect is considered in terms of the degradation process. Cylindrical specimens made of plain concrete matrix and with added fibre in various percentage quantities were tested to examine the durability of the mixture by measuring the electrical resistivity. The results are compared to the findings from a similar project. The paper deals with aspects influencing the results of chloride diffusion in concrete.

The enhancement of 2D model for the diffusion of chloride ions into reinforced concrete considering the time-dependent diffusion coefficient is discussed in the article. The non-stationary Finite Element Model is based on the four-node isoparametric element. The algorithm is implemented in MatLab compatible environment and an important part of source code is presented. The results of Finite Element Analysis are compared with the results of 2D analytical diffusion model.

The paper presents a general procedure of numerical analysis of the steel structure in case of cyclic loading. The basic recommendations that can be applied to different details, are discussed. The article shows examples of the truss structure loaded with a crane track, but also applicable to other types of constructions. There are basic ideas of the whole process, which is divided into several parts. The beginning of the process is to determine the influence line from the simplified model of the whole structure. A stochastic estimation of the load effect associated with the load history in combination with the influence line is utilized. The complex 3D FEM model for estimation of residual life of the chosen detail is the main result of the analysis.

The paper presents a possible statistical evaluation of the climate data, namely temperature and relative humidity, with respect to the rapid evaluation of the risk of reinforced concrete corrosion in the laboratory conditions. Data on temperature and humidity from Leoš Janáček Ostrava Airport over the last ten years are analysed. The processed data will be used as the set up for the climate chamber where the concrete samples with steel rods will be placed.

Fatigue crack damage depends on a number of stress range cycles. This is a time factor in the course of reliability for the entire designed service life. Three sizes are important for the characteristics of the propagation of fatigue cracks - initial size, detectable size and acceptable size. The theoretical model of fatigue crack progression can be based on a linear fracture mechanic. Depending on location of an initial crack, the crack may propagate in structural element e.g. from the edge or from the surface. When determining the required degree of reliability, it is possible to specify the time of the first inspection of the construction which will focus on the fatigue damage. Using a conditional probability and Bayesian approach, times for subsequent inspections can be determined. For probabilistic modelling of fatigue crack progression was used the original and new probabilistic method - the Direct Optimized Probabilistic Calculation (“DOProC”), which uses a purely numerical approach without any simulation techniques or approximation approach based on optimized numerical integration.