WORLD FOR CIVIL

NUMBER OF CONNECTORS REQUIRED FOR BUILDING CONSTRUCTION

The total number of connectors to resist V _h is computed from V _h / q, where q is the allowable shear for one connector, kip (kN). Values of q for connectors in buildings are given in structural design guides.

The required number of shear connectors may be spaced uniformly between the sections of maximum and zero moment. Shear connectors should have at least 1 in (25.4 mm) of concrete cover in all directions; and unless studs are located directly over the web, stud diameters may not exceed 2.5 times the beam-flange thickness.

With heavy concentrated loads, the uniform spacing of shear connectors may not be sufficient between a concentrated load and the nearest point of zero moment. The number of shear connectors in this region should be at least

N ₂ = N ₁ [ ( M b / M _{m a x} ) - 1] / ( b - 1 )

where M = moment at concentrated load, ft kip (kN-m)

M _max = maximum moment in span, ft kip (kN-m)

N ₁ = number of shear connectors required between M _{m a x} and zero moment

b = S _{t r} / S _s or S _{e f f} / S _s , as applicable

S _{e f f} = effective section modulus for partial composite action, in ³ (mm ³ )

Shear on Connectors

The total horizontal shear to be resisted by the shear connectors in building construction is taken as the smaller of the values given by the following two equations:

V _h = 0.85 f ^‘ _c A _c / 2

V _h = A _s F _y / 2

where V _h = total horizontal shear, kip (kN), between maximum positive moment and each end of steel beams (or between point of maximum positive moment and point of contraflexure in continuous beam)

f ^‘ _c = specified compressive strength of concrete at 28 days, ksi (MPa)

A _c = actual area of effective concrete flange, in ² (mm ² )

A _s = area of steel beam, in ² (mm ² )

In continuous composite construction, longitudinal reinforcing steel may be considered to act compositely with the steel beam in negative-moment regions. In this case, the total horizontal shear, kip (kN), between an interior support and each adjacent point of contraflexure should be taken as

V _h = A _{s r} F _{y r} / 2

where A _{s r} = area of longitudinal reinforcement at support within effective area, in ² (mm ² ); and F _{y r} = specified minimum yield stress of longitudinal reinforcement, ksi (MPa).