Advanced Materials Research Vol. 1020

Abstract: The paper discusses selected aspects on numerical modelling of historical masonry structures. Linear elastic material models are mentioned first, and then non-linear models are discussed. The paper includes several examples of solutions which have been done with use of these models. There is also an example of results which can be obtained from anon-linear analysis of masonry structures. The finite element method is used for computations.

Abstract: In a series of dynamic issues of continuum, a special role play surfaces of discontinuity. These surfaces are divided two areas of the body that are characterized by significantly different solutions of dynamics equations. All disturbances propagate with finite speed in the continuum. The purpose of this paper is to discuss the propagation of surface discontinuities in isotropic material with the hyperelastic potential Blatz-Ko. These disorder, according to the assumptions is the shock wave, or a wave of strong discontinuities.

Abstract: The paper presents the influence of fly ashes for the parameters which define the characteristics of the air pore and frost resistance of aerated concrete. Concrete which was used in the maximum allowable amount of fly ashes and different amounts of air admixture have been evaluated. Test of concrete mix have been performed such as the slump cone consistency and air content with pressure method used. Compressive strength, the depth of water penetration under pressure, at 150 cycles freeze resistance and the characteristics of the air pores have been evaluated for concrete. Parameters characterizing the pore structure have been marked: the total air content in concrete A, the ratio of pores location L, the content of micropores A₃₀₀. The results of the study have shown that it is possible to provide good frost resistance of concrete containing fly ashes. Air content of about 4% provides increased resistance to frost well as the use of fly ashes. The condition of frost resistance is to ensure the proper pore structure of the aircraft.

Abstract: Aim of this article is in presentation of results of dynamic tests of reinforced round timber bolted connections with slotted – in steel plates. Multicyclic dynamic (fatigue) tests in tension were made with round timber joints on pulsator. Results of laboratory tests have been statistically evaluated and completed with graphical records of carrying capacity of connections in tension corresponding to number of loading cycles.

Abstract: In the context with the solution of interaction of foundation structures and subsoil is complexity of a static solution given mainly by selection of a computational model, effects of physical-nonlinear behaviour of such structure and co-effects of the upper structure and the foundation structure. The purpose of this paper is to compare subsidence of the foundation measured during the experiment and numerical calculations based on FEM. This paper describes how calculated deformations depend on parameters of subsoil modelled by 3D finite elements. The parametric study includes charts of the dependence of resulting deformation on the choice of boundary conditions, on the size of the modeled area represents the subsoil, on the depth of 3D subsoil model and the size of the ground area 3D subsoil model.

Abstract: The aim of the paper is to investigate the flexural behavior and property changes of concrete structures reinforced by steel fibers (SFRC) and to use the results for carrying capacity assessment of SFRC post-cracked slab on ground structure with subsoil interaction effect. Because the national codes cover neither design nor assessment of SFRC structures the investigation is generally based on the nonlinear fracture mechanics models to establish the stress-crack opening and load-crack mouth opening displacement relationship. Then the flexural tensile strength and residual flexural tensile strength of the post-cracked SFRC structure is determined with respect to subsoil interaction.

Abstract: The paper deals with both the theoretical aspects and the practical experience with temporary steel bridge dynamic analysis. Since the moment people built the first bridge it became necessary to replace it in case of natural disasters like wind storms, floods, earthquakes, tsunami or wars and terrorist attacks. As a construction of a stable bridge lasts for a long time, the solution is a temporary bridge - a steel bridge structure designed especially for fast and repeated assembly and disassembly. The paper presents experimental analysis of steel bridge dynamic properties. The experimentally measured results are compared to theoretically calculated ones. Besides frequency analysis of supporting structure, the noise of the bridge during car passes is also measured and analyzed as nowadays traffic noise becomes a more and more important aspect, especially in case of temporary bridges. The bridge measurements are repeated for a clear bridge and for a bridge with anti-vibration mats attached to compare the arrangement results in decrease of traffic noise and the dynamic load of the bridge.

Abstract: The main theme of this article is a measurement processes description and the results of experimental destructive test of the fiber concrete foundation slab pattern. The purpose of this research was to make a behavior analysis of the fiber concrete foundation slab pattern focused on the interaction between foundation slab and the subsoil. This experiment was realized on model of real construction, especially - the National Supercomputing Center IT4 Innovations - significant construction built in campus of VŠB - Technical University of Ostrava.

Abstract: We solve interaction between the foundation base and the subsoil in civil engineering quite often. For the determination of stress in foundation structure is needed to determine the influence of the stiffness respectively pliability of subsoil to structural internal forces, and vice versa, how the stiffness of the foundation structure affects the resulting subsidence. It is necessary to compare the mathematical models with the actual behavior of the real structure. In 2013 was realised static load on testing equipment in the campus of Faculty of Civil Engineering, VSB–TU Ostrava. Dimensions of test element was 2000 x 2000 x 170 mm and the concrete slab was reinforced with steel fiber type DRAMIX 3D 65/60B6. During measurements were performed and recorded: tensometrical measurement on the surface of the slab, tensometrical measurement inside the slab, measuring the vertical load, measurement of the vertical deformation, measuring the stress on the interface of the slab and soil. Were also developed numerical models of this test in program Nexis. Comparison the test results with numerical models are presented in this paper. [1,9]

Abstract: The objectives of this paper are base characteristics of single-shear joints in elements of agglomerated wood. These characteristics (deformation and embedment strength) are determined on the basis of destructive laboratory testing (proceeded according to valid standards for destructive laboratory testing). Second part of this paper describes comparison of numerically and laboratory determined bearing capacity of these joints.