Experimental Tests - On Shear Behavior of Structural Elements Made of Steel Fiber Reinforced Concrete - page 53

Table III.3 Notations
a Shear span

A p Cross-sectional area of prestressed reinforcement

A s

Cross-sectional area of longitudinal tension reinforcement

A α Traditional shear reinforcement area

b f Flange width

b o Web width

d Effective depth

f bpt Constant bond stress at which the prestress is transferred to the concrete at release of

tendons

f ctd ( t ) Design tensile value of strength at time of release

f ctk Characteristic tensile strength value for the concrete matrix

f Ftuk Characteristic ultimate residual tensile strength value for ber-reinforced concrete

f p0 Stress in strands when the strain in the surrounding concrete is zero

f R3k

Residual flexural tensile strength corresponding to CMOD = 2.5 mm (according to EN
14651)

f R4k Residual flexural tensile strength corresponding to CMOD = 3.5 mm (according to EN

14651)

f yα,k Yielding strength of shear reinforcement steel

I Second moment of area

k f Factor to take into account the flanges contribution in the T-sections (EHE08 and

RILEM)

l crit Critical length

l pt Transfer length

l pt2

Upper bound value of the transmission length of the prestressing element: l pt2 =
1.2 · l pt

l x Distance of section considered from starting point of the transmission length

S First moment of area above and about the centroidal axis

V cu Design shear resistance attributed to concrete

V fu Design shear resistance attributed to bers

V su Design shear resistance provided by shear reinforcement

V u2 Design shear resistance

z Internal lever arm corresponding to the maximum bending moment. In the shear

analysis, an approximate value z = 0.9 d can be normally used

α Inclination of stirrups in relation to the beam axis

α l l x /l pt2 ≤ 1 for pretensioned tendons

=

ʲ

Reduction factor referred to the transmission length ( ʲ = 0.9)

ʳ c Partial safety factor for concrete material properties

ʳ s Partial safety factor for the material properties of reinforcement and prestressing steel

ʵ x Longitudinal strain at the mid-depth of the member

ʷ p1 Coef cient that takes into account the type of tendon and the bond situation at release

ʸ Inclination of the compression stresses

ʸ Reference angle of cracks inclination e

(continued)