Evaluation of the shear transfer mechanisms in reinforced concrete beams using photogrammetry

2019 ◽  
Vol 21 (1) ◽  
pp. 333-348
Author(s):  
Jónatas Valença ◽  
Ricardo N. F. Carmo
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Shear Transfer ◽  
Transfer Mechanisms

scholarly journals Influence of coarse aggregate on the shear strength of reinforced concrete beams

2020 ◽  
Author(s):  
◽  
Hoosen Ahmed Jajbhay
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Coarse Aggregate ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Shear Reinforcement ◽  
Shear Transfer ◽  
Coarse Aggregates

Research to accurately predict the shear capacity of reinforced concrete beams without shear reinforcement has been ongoing since the early 20th century. Aggregate interlock of the coarse aggregates at the shear crack interface is one of the internal mechanisms of shear transfer and a major contributor to the shear capacity of slender beams. It is plausible, therefore, to investigate if the coarse aggregate itself influences the shear capacity of a concrete beam. The influence of the type of coarse aggregate on the shear capacity of beams without shear reinforcement was investigated in this study. From the literature study an understanding of the properties of coarse aggregates was gained, the internal mechanisms of shear transfer in reinforced concrete beams without shear reinforcement were determined, and the parameters influencing shear strength were identified. Based on this information an experimental program was designed. Eighteen reinforced concrete beams without shear reinforcement were cast. The beams were cast from three different types of coarse aggregates commonly used in the Durban area, i.e., dolerite, quartzite and tillite. For each type of coarse aggregate two variations were tested, i.e., 13 mm and 19 mm maximum aggregate sizes. For each size of coarse aggregate, three concrete strengths were tested. The beams were loaded in a beam press, by applying an increasing point load offset from midspan to induce cracking on the shorter side, until shear failure of the beam occurred. For the three concrete strengths, beams cast from dolerite had the highest shear capacity while beams cast from tillite had less shear capacity than beams cast from quartzite coarse aggregate. Furthermore, beams cast from 13 mm maximum size coarse aggregate had higher shear capacity than beams cast from 19 mm aggregate. The conclusion may be drawn that the type and size of coarse aggregate does influence the shear strength of a reinforced concrete beam without shear reinforcement.

Mechanism of shear transfer in reinforced concrete beams

1977 ◽  
Vol 4 (2) ◽  
pp. 145-152
Author(s):  
K. N. Smith ◽  
S. M. Fereig
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Measurement Data ◽  
Reinforced Concrete Beams ◽  
Compression Zone ◽  
Interface Shear ◽  
Small Component ◽  
Shear Transfer ◽  
Dowel Action ◽  
Web Reinforcement

The mechanism of shear transfer in reinforced concrete beams with short shear spans is investigated with a view to defining the relative contribution of various component actions such as interface shear transfer across the characteristic inclined crack in such members, shear transferred by the uncracked compression zone, dowel action by the longitudinal tension reinforcement, and the contribution of the web reinforcement. The members tested and analyzed have a shear span to depth ratio of 1.5 and were loaded in the common framing situation involving shear on the sides of the members.For the beams either with horizontal web reinforcement or without any web reinforcement the distribution of internal forces was similar, with interface shear transfer, dowel action, and shear carried by the compression zone contributing to the capacity. In the case of members for which vertical web reinforcement was provided, interface shear transfer and dowel action were decreased to comparatively small component actions in the system. Acquisition of extensive measurement data and analysis of the behaviour history through various stages of loading permit the mechanism of shear transfer to be quantitatively defined.

Shear Strength of Reinforced Concrete Beams after Fire

2012 ◽  
Vol 256-259 ◽  
pp. 742-748 ◽  
Author(s):  
Kai Xiang ◽  
Guo Hui Wang ◽  
Hua Xin Liu
Keyword(s):  
Reinforced Concrete ◽  
Calculation Method ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Rc Beams ◽  
Test Analysis ◽  
Concentrated Load ◽  
Transfer Mechanisms ◽  
Reduction Factors

In order to research the calculation method of shear capacity for fire-damaged reinforced concrete (RC) beams, the reason of drop of shear capacity was analyzed from material properties and transfer mechanisms of RC beams after fire. Formulas of shear capacity were suggested for fire-damaged RC beams. Based on test analysis, the values of reduction factors of shear capacity were proposed under concentrated load. The results show that suggested calculation method is capable of predicting shear capacity of fire-damaged RC beams exactly. The values of reduction factors of shear capacity need further experiments research.

scholarly journals Experimental Evaluation on Components of Shear resistance of Reinforced Concrete Beams with Shear Reinforcement Provided

2021 ◽  
Author(s):  
Sreenivasa Prasad Joshi ◽  
Poluraju P
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Shear Resistance ◽  
Transfer Mechanism ◽  
Reinforced Concrete Beams ◽  
Structural Behavior ◽  
Compression Zone ◽  
Shear Reinforcement ◽  
Shear Transfer ◽  
Aggregate Interlocking

Abstract The contribution of aggregate interlocking and dowel force in shear strength of reinforced concrete beams was topic of research for many years. The precise forecasts of shear behavior were challenging to determine due to complication involved. The existing theories had focused on aggregate interlocking force and shear resistance arising due to concrete compression zone, neglecting the contribution of dowel force despite considering as significant constituent in shear transfer mechanism. The present investigation focuses on cogitating all components in shear transfer mechanism by providing shear reinforcement and keeping clear cover and effective span to depth ratio constant. Sixteen specimens were considered for parametric study by employing suitable variables such as increase in strength of concrete and variation in flexural reinforcement. Eight specimens were conventional beams and the remaining eight specimens were provided with preformed cracks. Moment vs. displacement curvature and strain vs. moment curvature were plotted to evaluate shear at uncracked compression zone and accordingly aggregate interlocking force and dowel force were determined based on the empirical formulas proposed. From the result it was confirmed that contribution of aggregate interlocking force and dowel force were insignificant and shear resistance due to uncracked compression zone is the sole contributor in shear transfer mechanism. Structural behavior of concrete beams was also studied and it was confirmed that beams with preformed cracks exhibited better structural behavior when related to conventional beams.

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