No abstract

Abstract. The paper refers to the importance of test results uncertainty in the assessment of the construction product performance. Uncertainty understood as dispersion attributed to any value which is result of the tests, calculations or other evaluations, occurs at every level of assessment (material, product, construction). Authors presented the various approaches to uncertainty estimation, especially in situation of small number of tests results which is characteristic for testing of construction products. Effects of uncertainty on final assessment of construction product was analyzed using the example of bearing capacity of thin-walled structure obtained by numerical calculation. Different values of material tests uncertainty resulting from different approaches to its assessment was taken into account. It was demonstrated that the difference in the results of strength tests of a material, which falls within the limits of uncertainty, may result in a very significant difference in the evaluation of a structure.Key words: uncertainty, numerical calculation, uncertainty influence on product assessment. Each value resulting from tests may only be considered in terms of probability. Unfortunately, in a small number of cases it is possible to express this probability using a probability density function (PDF) which is characterised by the expectation value and standard deviation (SD). In all tests which yield qualitative results (ordinal scale with two categories e.g. "fulfilled", "not fulfilled") or semi-quantitative results (ordinal scale with more than two categories), which, in the authors' opinion, are the majority of tests to which construction products are subjected, the determination of a PDF is an issue requiring extensive inter-laboratory tests performed on repeatable items [5][6][7]. Usually this is not possible for tests on construction products.Linking a value being measured with a PDF that is assigned to it is much easier for quantitative methods, for which the estimation of the uncertainty of a test result, allowing one to provide a PDF, is subject to numerous guidelines and instructions. The basic principles have been developed by the Joint Committee for Guides in Metrology [8], and are commonly applied by virtually all laboratories. However, as will be demonstrated for destructive (e.g. mechanical) testing, the estimation of uncertainty may be associated with numerous ambiguities.Presented by Walker et al. [9] typology and terminology of harmonized uncertainty provide uncertainity identification by location, including inter alia parameter uncertainty (associated with the variability of input data) and model uncertainty (associated also, but not only with lack of sufficient understanding of the system). These two kind of uncertainty sources are presented in test results and in estimation of uncertainty of the test results (uncertainty of estimated uncertainty). Variability relating to laboratory testing results has many components. Some of them, e.g. metrological parameters of testing equipment, ...

Abstract. The paper presents problems related to the numerical modeling of profiled steel sheets used as self-supporting arch structures for roof covering. The rules of preparing and full analysis of a set of numerical models of these elements with a different level of complexity are given. The models are evaluated by comparing numerical results with the results of extended experimental tests performed by 3D Digital Image Correlation (DIC) method. For each model the comparison of numerical and experimental results has been made for samples of a single-wave trapezoidal profile with corrugated web and lower flanges subjected to compression and bending. The full-field analysis allows to determine the allowed simplification of numerical models which do not affect in significant way the reliability of the results. The proposed methodology is the first step in the development of full assessment methodology for different types of self-supporting arch structures produced by ABM technology.

Optics as the enabling technology is applied in many applications of engineering, medicine, multimedia and conservation of cultural heritage. Most of these applications require close cooperation with the end user and often they enforce modification and enhancement of an optical tool. In the paper we show how optical metrology, specifically the application of digital image correlation method is implemented to two completely different tasks: performing preoperating tests of low cost building structures subjected to loading conditions which simulate the natural load e.g. introduced by the weight of snow and monitoring of canvas paintings for tracking humidity-induced deformations, which may appear in museum (or other location of a piece of art e.g. church).The presented examples are the background for a general discussion on different measurement scenarios with application of DIC method, as well as the required enhancements and modifications which have been introduced.

No abstract

In this work pre-operating tests of low-cost building structures have been presented. A hybrid experimentalnumerical methodology has been used to determine the influence of an external, environmental load on the overall endurance of a hangar made of self-supporting metal-plates. Numerical simulations carried out on a FEM model have been consequently verified by measurements of the structure performed with the 3D Digital Image Correlation method and as a result, a detailed, calibrated FEM model of the structure has been developed.

No abstract

This paper analyses the mechanism of the loss of functional properties of water-impermeable products used under ceramic tiles bonded with adhesives. Recorded damages were caused by selected ageing factors and were measured by the loss of adhesion of individual layers of the set. The analyzed phenomenon is found mainly on terraces and balconies located in a mid-European transitional climate, i.e., exposed to temperatures passing through 0 °C for three seasons a year. The tests reflected the action of three main functional factors, i.e., temperatures, water and freeze/thaw cycles. Tested waterproof coatings were grouped into three types, i.e., dispersion, cementitious and reaction resin-based products. Research kits consisted of liquid-applied water-impermeable products laid on a concrete substrate, adhesives and tiles. Comparing the effects of the action of the above-mentioned ageing factors revealed that water has the greatest impact on the reduction of the tensile adhesion strength of such sets. The adhesion of waterproof coatings to the concrete substrate showed higher values than the adhesion between the waterproof coating and the tile adhesive layers, regardless of the coating material. Both for samples not exposed to ageing factors, and for those exposed to such impacts, failure usually occurred in the adhesive layer or between the tile adhesive and the waterproof coating, without damaging the waterproof layer. The loss of adhesion of finishing layers to the substrate was not accompanied by a loss of tightness of the waterproof coating. The impact of negative water ageing was particularly destructive on the adhesion of cement-based tile adhesives to waterproof coatings made of polymer with a water dispersion of absorbability above 7% (V/V). There was no correlation among the results of adhesion of the finishing layers to the waterproofing layer after the action of the three ageing factors, i.e., water contact, elevated temperature and freeze/thaw cycles.