An analytical model to determine the shear capacity of prestressed continuous concrete beams

Abstract

<p>Structural reassessments of existing older prestressed concrete bridges based on current German standards often uncover substantial deficits in terms of the required shear reinforcement in the main girders in longitudinal direction. This is due to the negligence of the concrete shear capacity that can be determined using the<i>compressive arch model</i>as long as plane sections remain plane and only vertical cracks due to bending occur in state II. In case of inclined cracks due to shear plane sections do not remain plane. An<i>extended compressive arch model</i>is derived from experimental and numerical investigations that can determine the concrete shear capacity analytically even in case of existing inclined cracks in state II. This model also takes into account that parts of the acting shear forces are covered by the truss model.</p>

Shear and interface shear of semi‐precast slabs with lattice girders under monotonic loading

“…Investigations on continuous beams with shear reinforcement 19–24 also confirm the increase in shear resistance with decreasing shear slenderness. However, this effect is decreasing to zero with increasing shear reinforcement ratio.…”

“…The results of recent investigations on slab stripes without shear reinforcement 2,18 confirm these relationships (Figure 2b). Investigations on continuous beams with shear reinforcement [19][20][21][22][23][24] also confirm the increase in shear resistance with decreasing shear slenderness. However, this effect is decreasing to zero with increasing shear reinforcement ratio.…”