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Refinement of Strut-and-Tie Model for Reinforced Concrete Deep Beams.

Panjehpour M, Chai HK, Voo YL - PLoS ONE (2015)

Bottom Line: This study aims to refine STM through the strut effectiveness factor and increase result accuracy.The ultimate shear strength of deep beams obtained from non-linear finite element modeling and STM recommended by ACI 318-11 as well as AASHTO LRFD (2012) were compared with the experimental results.The equation of the strut effectiveness factor from AASHTTO LRFD was then modified through the aforementioned empirical equation.

View Article: PubMed Central - PubMed

Affiliation: Department of Civil Engineering, Faculty of Science, Engineering, Technology and Mathematics (FOSTEM), INTI International University, 71800, Nilai, Malaysia.

ABSTRACT
Deep beams are commonly used in tall buildings, offshore structures, and foundations. According to many codes and standards, strut-and-tie model (STM) is recommended as a rational approach for deep beam analyses. This research focuses on the STM recommended by ACI 318-11 and AASHTO LRFD and uses experimental results to modify the strut effectiveness factor in STM for reinforced concrete (RC) deep beams. This study aims to refine STM through the strut effectiveness factor and increase result accuracy. Six RC deep beams with different shear span to effective-depth ratios (a/d) of 0.75, 1.00, 1.25, 1.50, 1.75, and 2.00 were experimentally tested under a four-point bending set-up. The ultimate shear strength of deep beams obtained from non-linear finite element modeling and STM recommended by ACI 318-11 as well as AASHTO LRFD (2012) were compared with the experimental results. An empirical equation was proposed to modify the principal tensile strain value in the bottle-shaped strut of deep beams. The equation of the strut effectiveness factor from AASHTTO LRFD was then modified through the aforementioned empirical equation. An investigation on the failure mode and crack propagation in RC deep beams subjected to load was also conducted.

No MeSH data available.


Related in: MedlinePlus

Stress-strain curve for steel reinforcement.
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pone.0130734.g009: Stress-strain curve for steel reinforcement.

Mentions: The steel for the finite element models was assumed to be an elastic-perfectly plastic material and identical in tension and compression. Fig 9 shows the stress-strain relationship for steel reinforcement used in this study.


Refinement of Strut-and-Tie Model for Reinforced Concrete Deep Beams.

Panjehpour M, Chai HK, Voo YL - PLoS ONE (2015)

Stress-strain curve for steel reinforcement.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482495&req=5

pone.0130734.g009: Stress-strain curve for steel reinforcement.
Mentions: The steel for the finite element models was assumed to be an elastic-perfectly plastic material and identical in tension and compression. Fig 9 shows the stress-strain relationship for steel reinforcement used in this study.

Bottom Line: This study aims to refine STM through the strut effectiveness factor and increase result accuracy.The ultimate shear strength of deep beams obtained from non-linear finite element modeling and STM recommended by ACI 318-11 as well as AASHTO LRFD (2012) were compared with the experimental results.The equation of the strut effectiveness factor from AASHTTO LRFD was then modified through the aforementioned empirical equation.

View Article: PubMed Central - PubMed

Affiliation: Department of Civil Engineering, Faculty of Science, Engineering, Technology and Mathematics (FOSTEM), INTI International University, 71800, Nilai, Malaysia.

ABSTRACT
Deep beams are commonly used in tall buildings, offshore structures, and foundations. According to many codes and standards, strut-and-tie model (STM) is recommended as a rational approach for deep beam analyses. This research focuses on the STM recommended by ACI 318-11 and AASHTO LRFD and uses experimental results to modify the strut effectiveness factor in STM for reinforced concrete (RC) deep beams. This study aims to refine STM through the strut effectiveness factor and increase result accuracy. Six RC deep beams with different shear span to effective-depth ratios (a/d) of 0.75, 1.00, 1.25, 1.50, 1.75, and 2.00 were experimentally tested under a four-point bending set-up. The ultimate shear strength of deep beams obtained from non-linear finite element modeling and STM recommended by ACI 318-11 as well as AASHTO LRFD (2012) were compared with the experimental results. An empirical equation was proposed to modify the principal tensile strain value in the bottle-shaped strut of deep beams. The equation of the strut effectiveness factor from AASHTTO LRFD was then modified through the aforementioned empirical equation. An investigation on the failure mode and crack propagation in RC deep beams subjected to load was also conducted.

No MeSH data available.


Related in: MedlinePlus