# Members requiring design vertical shear reinforcement: the values of `ν`_{1} and `α`_{cw} for the maximum shear resistance

_{1}

_{cw}

## Eurocode 2 part 1-1: Design of concrete structures 6.2.3 (3)

For members with vertical shear reinforcement, the shear resistance, `V _{Rd}` is the smaller value of:

(6.8) |

and:

V = _{Rd,max}α _{cw}b _{w}z ν _{1}f /(cot_{cd}θ + tanθ) | (6.9) |

## Recommendation

**Note 1: ** The recommended value of `ν _{1}` is

`ν`(see Expression (6.6N) - § 6.2.2 (6)).

**Note 2:** If the design stress of the shear reinforcement is below 80% of the characteristic yield stress `f _{yk}`,

`ν`may be taken as:

_{1}ν = 0,6 for _{1}f ≤ 60 MPa_{ck} | (6.10.aN) |

ν = 0,9 - _{1}f/200 > 0,5 for _{ck}f ≥ 60 MPa_{ck} | (6.10.bN) |

**Note 3:** The recommended value of `α _{cw}` is as follows:

1 for non-prestressed structures | |

(1 + σ/_{cp}f) for 0 < _{cd}σ ≤ 0,25 _{cp}f_{cd} | (6.11.aN) |

1,25 for 0,25 f < _{cd}σ ≤ 0,5 _{cp}f_{cd} | (6.11.bN) |

2,5 (1 - σ/_{cp}f) for 0,5 _{cd}f < _{cd}σ ≤ 1,0 _{cp}f_{cd} | (6.11.cN) |

where `σ _{cp}` is the mean compressive stress, measured positive, in the concrete due to the design axial force.