Assessing the Yield Point of Concrete Steels Based upon Known Chemical Composition

The incorporation of recycling, which is the production of raw materials from old buildings and devices, is an increasing trend in industries worldwide. This increase in recycling is motivated by the conservation of energy and environmental resources, in particular, the decrease of carbon dioxide and green house gas emission by the intensive burning during various technological processes. The procedures for determining the yield point and the other relevant mechanical properties of concrete steels produced from waste irons are very expensive. The high expense is due to the relatively small production quantities and considerable variation of the chemical composition as a consequence of the variety of the raw materials associated with the use of waste iron. The yield point is taken as a base point and is representative of the other mechanical properties (tensile, breaking strength and the proportion limit), enabling easier analysis. The yield point, Y, is defined as the stress value after which additional specimen elongation takes place, as clearly seen in Hook’s diagram, Figure 1 1 . For further simplification, the number of chemical elements within an alloy is reduced to the six elements: Mn, Si, Cr, Cu and P. Their influence on the yield point is shown in Figure 2 2,5 . This research represents an attempt to predict the mechanical properties of concrete steels produced by waste iron by means of mathematical modelling based on chemical analysis. This is a difficult problem to solve by classical programming due to the large number of variables. However, using the software package