EXPERIMENTAL INVESTIGATION OF THE INFLUENCE OF TENSILE STRAIN ON THE CRACKING OF R/C VERTICAL STRUCTURAL ELEMENTS

摘要

The main objective of this research is to study the phenomenon of cracking in the vertical structural elements of R/C constructions, in particular the columns and the walls, and more particularly in the extreme regions of the walls, namely the boundary columns. Various parameters of the phenomenon of cracking will be studied, e.g. load influence, tensile strain, etc. It has to be noted the fact that load application is a monotonic axial tensile loading that simulates the strain condition that takes place at the boundary edges of reinforced concrete seismic walls. Specifically, this type of loading simulates the tensile loading that takes place during the first semi-cycle of loading under seismic dynamic events. Experimental research takes place by the construction and use of a group of 4 experimental specimens subjected to different degrees of elongation. This test group examines the tensile parameter and how it affects the cracking. The test specimens in question are all reinforced with the same longitudinal reinforcement ratio (4.02%) and subjected to tensile degrees 10‰, 20‰ 30‰ and 50‰. Significant conclusions are reached on cracking, e.g. its extent, the size of the cracks, their positions, minimum crack width, maximum crack width, average crack width, number of cracks, etc.