Shear Resistant Mechanism into Base Components: Beam Action and Arch Action in Shear-Critical RC Members

Abstract:The progressive collapse analysis of reinforced concrete (RC) moment-frame buildings under extreme loads is discussed from the perspective of modeling issues. A threat-independent approach or the alternate path method forms the basis of the simulations wherein the extreme event is modeled via column removal scenarios. Using a prototype RC frame building, issues and considerations in constitutive modeling of materials, options in modeling the structural elements and specification of gravity loads are discussed with the goal of achieving consistent models that can be used in collapse scenarios involving successive loss of loadbearing columns at the lowest level of the building. The role of the floor slabs in mobilizing catenary action and influencing the progressive collapse response is also highlighted. Finally, an energy-based approach for identifying the proximity to collapse of regular multi-story buildings is proposed.

Section: Prototype Model Materials and Elementsmentioning

confidence: 99%

Modeling of RC Frame Buildings for Progressive Collapse Analysis

Petrone

Kunnath

2016

“…Another family of theoretical models relates concrete shear strength to the strain in the longitudinal reinforcement through various hypotheses regarding the crack location, orientation and the state of strain or stress (Zararis and Papadakis 2001;Tureyen and Frosch 2003;Park et al 2006;Jeong and Kim 2014). Recently, Shuraim (2014) introduced an approach, which relates the shear strength capacity or shear resistance in a concrete beam with the internal shear resulting from applied load, thus termed as shear demand.…”

Section: Initial Concrete Compressive Strain Ementioning

confidence: 99%

Experimental Verification of Resistance-Demand Approach for Shear of HSC Beams

El-Sayed

Shuraim

2016

The resistance-demand approach has emerged as an effective approach for determining the shear capacity of reinforced concrete beams. This approach is based on the fact that both the shear resistance and shear demand are correlated with flexural tensile strain from compatibility and equilibrium requirements. The basic shear strength, under a given loading is determined from the intersection of the demand and resistance curves. This paper verifies the applicability of resistance-demand procedure for predicting the shear capacity of high strength concrete beams without web reinforcement. A total of 18 beams were constructed and tested in four-point bending up to failure. The test variables included the longitudinal reinforcement ratio, the shear span to depth ratio, and the beam depth. The shear capacity of the beams was predicted using the proposed procedure and compared with the experimental values. The results of the comparison showed good prediction capability and can be useful to design practice.Keywords: shear strength, reinforced concrete beams, resistance, demand, high strength concrete, verification. Abbreviations A sArea of tension reinforcement, mm

“…Although a number of researches have been conducted to evaluate shear strength of reinforced concrete beams for the last century, it is still hard to well predict actual shear strength because shear behavior of reinforced concrete beams is very complicating due to many parameters such as concrete compressive strength, stirrup ratio, shear span-todepth ratio, longitudinal reinforcement ratio, and so on Lee et al 2010;Labib et al 2013;Russo et al 2013;Mofidi and Chaallal 2014;Jeong and Kim 2014;Chiu et al 2016;El-Sayed and Shuraim 2016). On evaluating shear strength of reinforced concrete beams, even shear design provisions around the world are much different through each other, even from theoretical basis, specifically for reinforced concrete beams with stirrups (Eurocode 2 2004;ACI 318 2014;CSA A23.3 2014).…”

Section: Introductionmentioning

confidence: 99%

Single Web Shear Element Model for Shear Strength of RC Beams with Stirrups

Jude

Lee

2018

In this paper, an analytical model to rationally evaluate the shear strength of reinforced concrete beams with stirrups has been developed. In the developed model, a shear critical section has been idealized with a single web element for shear and the top and bottom chords for flexure, respectively. With the longitudinal strain at the mid-depth in the shear critical section, evaluated from the flexural analysis, the web element has been analyzed, based on the analysis procedure modified from the modified compression field theory finite element formulation. Through the comparison with the test results of 201 reinforced concrete beams with stirrups exhibiting shear failure before flexural yielding, it was investigated that the developed model well predicted the actual shear strength of reinforced concrete beams with stirrups. In addition, it was investigated that the developed model rationally considered the effect of main parameters such as concrete compressive strength, shear span-depth ratio, stirrup ratio, and member depth. Through simplification, the developed model can be useful to develop more rational shear design provisions for reinforced concrete members with stirrups.