*2.1. Materials Used for Tests*

High-strength cement composites w/(c + Sf) = 0.31, Portland Cement CEM I 42.5R (c), silica fume Sf = 10%c, siliceous fly ash 20%c, superplasticizer Sp, tap water (w).

Synthetic-structural polypropylene fibers (ASTM C-1116): density 0.91 kg/dm3, ft = 620–758 MPa, E = 4.9 GPa, l = 54 mm, d = 0.48 mm, l/d = 113.

The specimens were reinforced with a polypropylene fiber volume of Vf = 5%. The samples with dimensions 40 × 40 × 160 mm were cut out from pre-formed slabs. Each beam was turned by 90◦ and cut to the depth of 7 mm.
