Institute of Fundamental Technological Research

The aim of the present communication is to propose a method for determining the states of strain and stress without introducing the usually assumed models of hypothetic stress-strain realations. This can be done for bodies such as concrete and soils, into which measuring gauges can be introduced. Thus, the method advanced opposes the eluding in investigations of continuous media the most essential point of scientific research the cognition of the real mechanism of the dependence between strain and stress fields. It opposes the eluding the proper way of proceeding, i.e., the replacing by hypothetical “models” the real objects to be studied.

The paper deals with measurements of the six strain-components inside a concrete cylinder loaded by axial compression. The measurements have been performed by means of a spatial system of electrical strain-gauges, located in the vicinity of the mid-length cross-section of the cylinder. As a result of investigation, the diagrams of all strain-components as a function of applied load are obtained. In conclusion, attention is drawn to the fact that the existing state of strain differs from that obtained on the basis of usual hypothesis. This fact concerns the shearing strains which appeared during the axial compression arranged with technical accuracy, and the variability in the investigated cross-section of longitudinal strains parallel and perpendicular to the direction of loading.