B. Martinperez et Sj. Pantazopoulou, MECHANICS OF CONCRETE PARTICIPATION IN CYCLIC SHEAR RESISTANCE OF RC, Journal of structural engineering, 124(6), 1998, pp. 633-641
Citations number
28
Categorie Soggetti
Engineering, Civil","Construcion & Building Technology
In conventional design of shear-dominated reinforced concrete elements
shear resistance is assumed to comprise reinforcement and concrete co
ntributions. Because the design code assumes these contributions to be
uncoupled and independent of the load history, the estimated nominal
shear strength of reinforced concrete is insensitive to the number and
intensity of imposed load cycles. However, in accordance with recent
experimental evidence, the concrete contribution to shear resistance d
egrades with increasing ductility demand, thereby rendering the estima
ted nominal shear strength conservative for low levels of deformation,
and increasingly unconservative for larger imposed displacements. Thi
s paper attempts to establish the parametric relationship between shea
r strength and deformation demand through a nonlinear analytical model
of cyclic plane-stress states in reinforced concrete. The formulation
establishes tensorial, constitutive, and equilibrium relations, all e
xpressed in terms of average stresses and strains. The model was used
to conduct a parametric investigation of several design variables. The
rate of strength degradation and ductility capacity were used to gaug
e the parametric sensitivity of the problem. It was found that the cal
culated concrete shear contribution degraded with increasing deformati
on demand and was enhanced by an increase in the level of axial load a
nd the amount of transverse reinforcement. A simplified design equatio
n was developed from the analytical results to express the dependence
of the concrete contribution term on the intensity of imposed deformat
ion demand.