Research of Deformative Properties of Concrete Taking into Account the Descending Branch of Deformation

Abstract In recent years due to the introduction of computer technology in the process of calculating and conducting experiments the ability of researchers in the knowledge of various, accurate processes, including the nature of the work of concrete on the downstream branch of deformation significantly expanded. Modern methods of measurement allow to fix, for example, deformation, to an accuracy of 0.0001 mm, which allows deeper penetration into the essence of the phenomenon of destruction. Widespread are so-called ‘hard’ test machines in which the change in load is followed by a change in deformation in contrast to the traditional experiment when the load increases continuously up to a destructive value. Such machines allowed for the first time to show the exact type of the curve of ‘stress – deformation’ with the construction of a descending branch (plot of the diagram, going after the point of maximum load). An experiment was conducted to study the deformation of concrete simultaneously on two different presses with a hard loading mode and by increasing the loading. The analysis of the deformation of concrete prisms on these presses is carried out. A complete diagram of deformation of concrete has been constructed taking into account the descending area of concrete deformation. Comparing of the received data with the normative confirms the adequacy of the data received.