PSI - Issue 13

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Oldřích Sucharda et al. / Procedia Structural Integrity 13 (2018) 1533 – 1538 Sucharda O., Lehner P., Kone č ný P., Ponikiewski T./ Structural Integrity Procedia 00 (2018) 000–000

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(a) (b) Fig. 1. Correlation of the cracking strain and the tensile stress along the process zone: (a) exponential; (b) from fracture energy in SCC-SFR. Parameter w c is the limiting crack opening and f 1 and f 2 are the beginning and end softening related stresses, G f is the fracture energy needed to create a unit area of stress-free crack, f ef t is the effective tensile strength derived from a failure function. 1.3. Research significance The article aim is to determine and extend the knowledge about material properties of a selected SRFC mixture with a fibre content of 1%. This information can be used for nonlinear analysis and design of structural elements. The expanding of materials knowledge is based on an inverse analysis from the working diagrams of standardized laboratory tests. The current method of inverse analysis and identification is based on stochastic modelling and multi criteria analysis. Due to the complexity of tasks, possible approaches and their simplification are introduced. 2. Experiment description The evaluated experiment, calculations and results are part of the extensive campaign dealing with durability of concrete structures. The laboratory experiments were conducted at the laboratories of Silesian University of Gliwice and VŠB - Technical University of Ostrava. The part presented here has a focus on the self-compacting concrete reinforced with steel fibres (SCC- SFR). A comprehensive range of tests comprised from basic mechanical properties, fracture test as well as measurements of electrical resistance and chloride permeability tests (Lehner et al., 2018).

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(b) Fig. 2. (a) Chosen steel fibres; (b) the testing of concrete beam in laboratory compression machine

The SCC mixtures was composed of: 490 kg/m 3 cement type I 42,5 R, 201 kg/m 3 of water, 807 kg/m 3 of sand, 807 kg/m 3 of river gravel 2/8, 2.5% Superplastificator Glenium sky (12.25 kg) and 0.4% Stabilizator RheoMatrix (1.96