New Knowledge in the Field of Reduction of Shear Stress in the Foundation Structures of Concrete or Masonry Structures

Abstract

This paper deals with application of sliding joint into foundation structures which can be very helpful in case that the foundation structure is exposed to effect of relative horizontal deformation. These deformations can be created direct in the structure from the effect of creep or shrinkage of concrete, from the effect of pre-stressing of foundation structure or they can arise in the subsoil as a consequence of undermining. Sliding joints are often created from asphalt belts which help to increase of friction forces in the foundation bottom. Due to fact that today ́s market gives a lot of new modern materials, the laboratory tests are carried out to verify their behavior at the Faculty of Civil Engineering VŠB Technical University of Ostrava (Czech Republic). The basic principle of these tests is to simulate real behavior sliding joint in foundation structure and great attention is also focused on thermal sensitivity of majority of used materials. Thermal sensitivity at the action of mechanical load relates closely with their rheological properties. Rheology is the science about deformation of substances in the dependence on time and it helps to describe difficult materials using simpler rheological materials models. A right created rheological model of asphalt belt could be used to prediction of behavior of sliding joint with regard to time of loading and ambient temperature. The knowledge of change of asphalt belt behavior consequently to temperature change could be used in the future to design of this type sliding joint where the temperature will be not only monitored but also managed in the dependence on necessity of increasing or decreasing of shear resistance. Partial results from laboratory tests as well as current conclusion will be presented in this paper.