(3) In Table 4.11 and Table 4.12 the steel stresses used should be evaluated for reinforced concrete on the basis of the quasi-permanent loads and for prestressed concrete on the basis of the frequent loads and the relevant estimated value of prestress.

In Table 4.11, if the stresses arise dominantly from restraint then a steel stress equal to Gs in Equation (4.78) should be used.

(4) Beams with a total depth of 1.0 m or more where the main reinforcement is concentrated in only a small proportion of the depth should be provided with additional skin reinforcement to control cracking on the side faces of the beam. This reinforcement should be evenly distributed between the level of the tension steel and the neutral axis and should be located within the stirrups. The area of the skin reinforcement should not be less than the amount obtained from taking k as 0.5 and Gs as fyk The spacing and size of suitable bars may be obtained from Table 4.11 or Table 4.12 assuming pure tension and a steel stress of half the value assessed for the main tension reinforcement.

(5) Cracking due to tangential action effects may be assumed to be adequately controlled provided the spacings of stirrups given in Table 4.13 are satisfied. No check is required in members which do not require shear reinforcement (i.e. where Vcd > Vsd), or where 3Vcd > Vsd, as the member will not have developed shear cracks under service loads.

Table 4.13 — Spacing of stirrups in beams for crack control

(VSd - 3Vcd) Pw bwd (N/mm2)

Stirrup spacing


r 50

Greener Homes for You

Greener Homes for You

Get All The Support And Guidance You Need To Be A Success At Living Green. This Book Is One Of The Most Valuable Resources In The World When It Comes To Great Tips on Buying, Designing and Building an Eco-friendly Home.

Get My Free Ebook

Post a comment