EXPERIMENTAL STUDY OF THE NATURE OF INTERACTION OF STEEL FIBRES EQUIDIRECTIONALLY LOCATED IN PARALLEL TO FORCE IN FINE-GRAINED SLAG CONCRETE

At present, the use of modern technologies is becoming more urgent. This concerns both construction engineering and structural design standards. There is a need for a wider use of computer technology, which will allow solving multifactorial tasks taking into account actual stress-strain state of structures at all the stages of their operation with the help of a nonlinear deformation model in the future. The objective of this work is to study the nature of the interaction of steel fibers equidirectionally located in parallel to force in fine-grained slag concrete, in particular, to determine the coefficient characterizing the change in the contribution to the work of the fibre reinforcement unit depending on the length of the adjacent fibers embedment in the slag concrete and the quality of adhesion between them, and construction of a graphical model of steel fibers operation in cinderblock matrix, diagrams of deformation (state) of concrete, reinforcement and fiberы which are an integral characteristic of physical and mechanical properties of materials. Tests for the extraction of steel fibers with single offset bends at the ends of fine-grained slag concrete have been carried out. Experimental dependences of steel fibers displacement on the applied load have been obtained. Based on the results of the experimental data analysis, formulas for determining the coordinates of piecewise-linear ‘load-displacement’ diagrams are proposed; they describe the displacement of a single fiber from fine-grained slag-concrete, which allows drawing conclusions concerning their mutual influence on the anchoring ability in fine-grained slag concrete. Dependencies for determining the coefficient characterizing the change in the contribution to the work of the fibre reinforcement unit depending on the length of the adjacent fibers embedment in the slag concrete and the quality of adhesion between these fibers and the slag concrete-matrix are proposed. The work also presents common dependencies, which can be used to construct analytical piece-wise diagrams ‘load-displacement’ and describe the work of fiber embedded in fine-grained slag concrete when calculating the units of building structures from steel-fiber-slag-concrete by means of a computer using the diagram technique.