Shear in wide reinforced concrete members.
Published: 2006
Language: eng
Number of pages: 455
ISBN-13: 9780494217924
Description: A system of manufactured headed bar assemblies was evaluated as web reinforcement for one-way shear. Specimens incorporating these assemblies and failing in shear were predicted well by the sectional shear capacity models.The objective of this study was to establish the significant parameters for predicting sectional shear capacity for wide reinforced concrete members. The results of 30 tests on large specimens are reported.Large, wide reinforced concrete beams and thick slabs are frequently used as economical transfer elements where the total structural depth must be kept to a minimum. Both systems supply large cross-sections to resist shear forces. However, major North American building codes are not consistent in their treatment of shear in wide beams and in slabs, as compared to narrow beams.The influence from supports or loading widths narrower than the member width was investigated. The shear capacity of members with and without web reinforcement decreased as the partial-to-full width ratio decreased. A linear model was developed to adjust existing sectional capacity predictions for this influence.When web reinforcement was well distributed across the width of a wide member, the shear stress at failure was in good agreement with the shear capacity models. However, the shear capacity decreased as the spacing of web reinforcement legs across the width increased. A limit on the spacing over the width was proposed as the lowest of d, every 4th longitudinal reinforcing bar in a layer, or 600 mm. An improvement to the CSA A23.3-04 model was proposed, to directly consider the longitudinal spacing of the web reinforcement.For members without web reinforcement, tests results showed that member width or the inclusion of temperature reinforcement did not influence the shear stress at failure. The shear stress at failure decreased as the member depth increased and as a measure of the member axial strain increased. The CSA A23.3-04 shear provisions provided more consistent estimates of capacity than the ACI 318-05 provisions, by considering these influences.
Notes: Source: Dissertation Abstracts International, Volume: 68-01, Section: B, page: 0475.

Thesis (Ph.D.)--University of Toronto, 2006.

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