A good characterization of tensile strength of the materials is necessary for the correct application of the Theory of Critical Distances (TCD). For this reason, the necessary pieces are prepared in order to perform Brazilian tests, which will allow us to obtain the parameter of interest indirectly.
4-point bending tests performance begins. The initial experimental programme comprises 180 samples in total, for notched radii varying from 0.15 mm up to 15 mm. Prior to these tests, an inspection of each piece is carried out, verifying its dimensions and looking for possible defects that may lead to erroneous results.
The specimens were dried at a temperature of 70 (+/- 5) ° C until reaching constant mass in accordance with UNE-EN 13161: 2008. After drying, the specimens have been stored until thermal equilibrium at room temperature is reached, taking into account that the tests must be carried out within 24 hours after removal from the Read more about Pre-test conditioning[…]
After sending the corresponding specimens to Portugal, the company Frontwave begins performing the notches with radii of 4 mm, 2 mm, 1 mm, 0.5 mm and 0.15 mm. The larger notches are made by abrasive discs, while the smaller ones require a diamond wire for the cuttings.