Distribution of material parameters
Apart from the minimum steel parameters declared by the manufacturers, it is also very important to know the extent to which they are actually preserved and what is the nature of the distribution of these values. CPJS conducts control of the material testing results of B500SP reinforcing steel with the EPSTAL mark. Statistical reports show that the minimum steel parameters declared by the manufacturers are met with a high safety margin for all rod diameters.
The following links contain statistical results of the strength test results conducted by CPJS-certified companies under Factory Production Control. These studies included an attempt to stretch rods of different diameters, based on which the following parameters of steel were determined:
- Re - yield strength (corresponding to the value of the fyk)
- Rm - endurance (corresponding to ftk value)
- Agt - elongation at maximum force (corresponding to ɛuk values)
The results are shown in histograms showing the incidence of steel samples for which the parameter value is within a certain range. In order to facilitate interpretation and to show the minimum safety value of the parameters, the red dashed line defining the minimum values of the parameters required by the PN-H-93220 standard is followed.