Initial Parameters Affecting the Multilayer Doubly Curved Concrete Shell Roof

Table 2

Parameters of Dramix steel fibres in shell.

Diameter (d)	0.5 mm ± 0.04 mm
Length (L)	30 mm ± 2 mm
Ratio (L/d)	60
Hook length (l and l’)	2–4 mm
Hook depth (h and h’)	1.8 mm + 0.3 mm
Bending angle (α and α′)	45^°
Torsion angle	<30^0
Number of fibres in 1 kg	17400
Tensile	>1.2 kN/mm^2