Key Engineering Materials Vol. 832

Abstract: The purpose of paper is to analyze approximate behavior of harmonic wave propagating in a layered composite. The composite was made of materials with hyperelastic Blatz-Ko potential. Using two special cases of constitutive equation of Blatz-Ko material, it was assumed that the layers are filled alternately with foam rubber and homogenous rubber. The two extreme layers are infinite material areas separated by two layers on the lengths d₁ and d₂. According to the assumptions in the work it was discussed harmonic wave in the form of longitudinal and transverse acoustic wave. Numerical analysis was carried out based on the work [1] using the material constants obtained on the basis of experimental studies in works [2-4].

Abstract: This paper discusses relations between structure of bi-material samples in 2D and their anisotropic indices and mechanical properties. The bi-material sample is designed to be close to masonry structure. Different ratios of elastic moduli of material are studied and computed material parameters are given.

Abstract: The paper deals with the possibilities of using probabilistic calculation methods for the assessment of structures in building thermal technology and energetics. The subject is particularly the performance of individual probabilistic calculation methods that can be used for this purpose and their basic principles. Following are then examples of these calculations used in practice.

Abstract: Glued laminated timber – Glulam is commonly used for the constructing of wooden structures in the interior and exterior. Wood as an organic material and may be the subject to a biological processes that can be a risk, mainly for construction on the exterior. Analyzed footbridge is made of glued laminated timber and is build in the Czech Republic. Analysis shows a serious disturbance caused by biological influences only a few years after construction completion. This article described summary of analysis of timber footbridge damage and their causes.

Abstract: This article deals with the topic of atmospheric corrosion. Atmospheric corrosion causes damage to nearly 80% of all existing steel structures. The main parameters of atmospheric corrosion are the time of wetness (TOW), air temperature and aggressive corrosive agents such as chlorides, sulfur dioxide and others. Currently, low alloy steels with improved atmospheric corrosion resistance called weathering steels are used for the steel structures located in outdoor environment. A protective layer of corrosion products is created on the steel surface and this layer can reduce continuation of corrosion of steel. The time of wetness together with the effect of aggressive corrosive agents are various for surfaces oriented vertically or horizontally. Experimental tests of atmospheric weathering steel were carried out to monitor the impact of location and position of surface on the different constructions. These tests allow monitoring the development of corrosion products in real exposures. The article presents a part of the research, which includes monitoring the development of the thickness of corrosion products with regard to the position on the structure. Research is developed to refine of prediction models with the aim of improving determination of corrosion losses during the service life of the structure. Second part of these experiments is dedicated to measuring the deposition rate of chlorides. Chlorides have a corrosive impact on the steel surface. Under normal conditions the chlorides does not create suitable environment for the development of a protective layer of corrosion products.

Abstract: The contribution focuses on the effect of selected input parameters on probabilistic estimation of chloride induced reinforced concrete bridge deck corrosion initiation. The reinforced concrete bridge deck with steel protected by epoxy-coating is considered. A finite element diffusion model in conjunction with a probabilistic method using Monte Carlo technique is used to address the inherited randomness of input variables. Presented parametric study shows the sensitivity of estimation of the corrosion initiation likelihood on variation of input parameters.