Flexural Behavior of Confined Masonry Walls Subjected to In-Plane Lateral Loads

2019 ◽  
Vol 35 (1) ◽  
pp. 405-422 ◽  
Author(s):  
Jorge Varela-Rivera ◽  
Luis Fernandez-Baqueiro ◽  
Jose Gamboa-Villegas ◽  
Adda Prieto-Coyoc ◽  
Joel Moreno-Herrera
Keyword(s):  
Aspect Ratio ◽  
Flexural Strength ◽  
Compressive Stress ◽  
Flexural Behavior ◽  
Masonry Walls ◽  
Hysteretic Model ◽  
Confined Masonry ◽  
Displacement Ductility ◽  
Axial Compressive Stress ◽  
Ductility Capacity

Results of a study on the flexural behavior of confined masonry walls are presented. Six walls were tested in a laboratory under reverse cyclic loads. The variables studied were the wall aspect ratio and wall axial compressive stress. The behavior of walls was characterized by yielding of the longitudinal steel reinforcement of vertical confining elements followed by vertical and diagonal cracks on the masonry panel. The failure of walls was associated with crushing concrete of vertical confining elements. Flexural strength increased as the wall aspect ratio decreased or the wall axial compressive stress increased. The flexural strength of walls was validated using flexural theory. A displacement ductility capacity of 6 and a drift ratio capacity of 1% were proposed for the walls. A hysteretic model based on four parameters was calibrated. This model represented well the flexural behavior of the studied walls.

Out-of-plane behavior of confined masonry walls with aspect ratios greater than one

2021 ◽  
Vol 48 (1) ◽  
pp. 89-97
Author(s):  
Jorge Varela-Rivera ◽  
Joel Moreno-Herrera ◽  
Luis Fernandez-Baqueiro ◽  
Juan Cacep-Rodriguez ◽  
Cesar Freyre-Pinto
Keyword(s):  
Experimental Study ◽  
Aspect Ratio ◽  
Compressive Stress ◽  
Masonry Walls ◽  
Confined Masonry ◽  
Aspect Ratios ◽  
Out Of Plane ◽  
Axial Compressive Stress ◽  
Compressive Strut ◽  
Failure Line

An experimental study on the out-of-plane behavior of confined masonry walls is presented. Four confined walls with aspect ratios greater than one were tested in the laboratory. Walls were subjected to combined axial and out-of-plane uniform loads. The variables studied were the aspect ratio and the axial compressive stress of walls. It was observed that the out-of-plane strength of walls increased as the aspect ratio or the axial compressive stress increased. Failure of walls was associated with crushing of masonry. Analytical out-of-plane strength of walls was determined using the yielding line, failure line, modified yielding line, compressive strut and bidirectional strut methods. It was concluded that the experimental out-of-plane strength of walls was best predicted with the bidirectional strut method.

scholarly journals Seismic Performance of Masonry Walls Built with New Type of Fired Shale Hollow Blocks

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Jian Wu ◽  
Liangcheng Zeng ◽  
Bo Wang
Keyword(s):  
Energy Dissipation ◽  
Aspect Ratio ◽  
Bearing Capacity ◽  
Compressive Stress ◽  
Seismic Performance ◽  
Stiffness Degradation ◽  
Masonry Walls ◽  
Secant Stiffness ◽  
Hollow Block ◽  
New Type

This paper presents the cyclic loading test results of a new type of fired shale hollow block masonry walls. Six specimens were designed including two specimens without reinforcements (bare walls) and four specimens constrained by structural columns (reinforced walls). The influences of aspect ratio, vertical compressive stress, and structural column on the seismic performance of the specimens were investigated. The failure mode, bearing capacity, ductility, stiffness degradation, and energy dissipation of specimens were analyzed. The results showed that the crack patterns of specimens changed from the horizontal straight shape (bare walls) to “X” shape (reinforced walls), and the corresponding bearing capacity, ductility, stiffness degradation, and energy dissipation of the specimens were improved. With the increase of the vertical compressive stress, the ductility and the secant stiffness of the specimens increased. Moreover, with the decrease of aspect ratio, the bearing capacity and secant stiffness of the masonry walls increased, while the energy dissipation capacity decreased. This paper confirms that fired shale hollow block walls could meet the seismic requirements through appropriate design, which could promote the application of this new type of block in civil engineering.

Evaluation of Fundamental UHPC Properties According to the Shape of Steel Fiber

2010 ◽  
Vol 452-453 ◽  
pp. 717-720 ◽  
Author(s):  
Gum Sung Ryu ◽  
Su Tae Kang ◽  
Jung Jun Park ◽  
Kyung Taek Koh ◽  
Sung Wook Kim
Keyword(s):  
Aspect Ratio ◽  
Flexural Strength ◽  
High Performance ◽  
High Performance Concrete ◽  
Steel Fibers ◽  
Flexural Behavior ◽  
Ultra High Performance Concrete ◽  
Aspect Ratios ◽  
Strength Tests ◽  
Shaped Fibers

This paper intends to examine the effects if the length and shape of steel fibers on the mechanical characteristics of ultra-high performance concrete (UHPC). Accordingly, the length (l) of the steel fibers with diameter (d) of 0.2 mm is varied as 13 mm, 16.3 mm and 19.5 mm and their corresponding aspect ratios (l/d) are 65, 82 and 98. Straight and wave-shaped fibers are adopted to manufacture UHPC. Thereafter, the effects of the aspect ratio and characteristics of the wave-shape of the steel fibers on the strength characteristics of UHPC are examined through compressive and flexural strength tests. The results showed small differences in the workability and compressive behavior but revealed that changing the length of the fibers and increasing the aspect ratio are improving the flexural behavior of UHPC. Specifically, the flexural strength was enhanced by 25% and the flexural toughness by 30%. Compared to rectilinear fibers, the adoption of wave-shaped fibers is seen to degrade the flexural behavior regardless of the aspect ratio. Consequently, using straight steel fibers and adopting larger aspect ratio seems advisable to improve the toughness of UHPC.

Shear and Flexural Behavior of Autoclaved Aerated Concrete Confined Masonry Walls

2018 ◽  
Vol 115 (5) ◽  
Author(s):  
Jorge Varela-Rivera ◽  
Luis Fernandez-Baqueiro ◽  
Rodrigo Alcocer-Canche ◽  
Jose Ricalde-Jimenez ◽  
Ricardo Chim-May
Keyword(s):  
Flexural Behavior ◽  
Masonry Walls ◽  
Confined Masonry ◽  
Autoclaved Aerated Concrete ◽  
Aerated Concrete

Out-Of-Plane Behavior of Confined Masonry Walls Subjected to Concentrated Loads (One-Way Bending)

2016 ◽  
Vol 32 (4) ◽  
pp. 2317-2335 ◽  
Author(s):  
Dante Navarrete-Macias ◽  
Jorge Varela-Rivera ◽  
Luis Fernandez-Baqueiro
Keyword(s):  
Aspect Ratio ◽  
Seismic Behavior ◽  
Axial Stress ◽  
Experimental Results ◽  
Masonry Walls ◽  
Cyclic Loads ◽  
Wall Panel ◽  
Confined Masonry ◽  
Plastic Analysis ◽  
Out Of Plane

This paper presents the results of a study on the out-of-plane seismic behavior of confined masonry walls. Five confined walls were tested under reverse cyclic loads. The variables studied were the axial stress and the wall aspect ratio. Analytical out-of-plane strength of walls was calculated considering the strengths of the wall panel and the concrete confining elements. The former was determined using the unidirectional strut method and the latter using a plastic analysis. It was observed that for walls with the same aspect ratio, as the axial stress increases, the out-of-plane strength increases. For walls with the same axial stress, as the aspect ratio increases, the strength decreases. Based on comparisons between analytical and experimental results, it was concluded that the models developed in this work predict accurately the out-of-plane strength of the walls.

An Experimental Study of Confined Masonry Walls with Varying Aspect Ratios

2015 ◽  
Vol 31 (2) ◽  
pp. 945-968 ◽  
Author(s):  
J. J. Perez Gavilan ◽  
L. E. Flores ◽  
S. M. Alcocer
Keyword(s):  
Aspect Ratio ◽  
Good Accuracy ◽  
Axial Stress ◽  
Masonry Walls ◽  
Inelastic Behavior ◽  
Ductility Demand ◽  
Confined Masonry ◽  
Aspect Ratios ◽  
Wide Range ◽  
Good Agreement

Results from an experimental series of seven full-scale confined masonry walls with height-to-length aspect ratios ( H/L) from 0.3 up to 2.2 are summarized. Results show that neither the level of axial stress nor the aspect ratio had a significant effect on lateral stiffness. Inelastic behavior of the walls, characterized by normalized stiffness degradation with ductility demand, can be estimated with good accuracy with a bilinear function for a ductility demand up to 4.5. A substantial increase in normalized shear strength was observed for walls with decreasing aspect ratio. A correction factor to the nominal cracking strength was deduced based on differences of the flexural deformations for squat and square walls. The factor was then compared to the experimental normalized strength with good agreement. A new expression for inclined cracking shear that can be used for a wide range of wall aspect ratios is proposed.

Bidirectional strut method: out-of-plane strength of confined masonry walls

2014 ◽  
Vol 41 (12) ◽  
pp. 1029-1035 ◽  
Author(s):  
Joel Moreno-Herrera ◽  
Jorge Varela-Rivera ◽  
Luis Fernandez-Baqueiro
Keyword(s):  
Sensitivity Analysis ◽  
Aspect Ratio ◽  
Analytical Method ◽  
Slenderness Ratio ◽  
Masonry Walls ◽  
Axial Loads ◽  
Confined Masonry ◽  
Out Of Plane ◽  
Arching Action ◽  
Compressive Strut

An analytical method to determine the out-of-plane strength of confined masonry walls is developed. The method is called the “bidirectional strut method.” Walls with and without openings subjected to combined out-of-plane and axial loads are considered. The method is based on two-way arching action. Masonry compressive strut forces are transferred eccentrically to the concrete confining elements. Flexural and torsional effects, together with the variation of displacements along these elements, are considered. Analytical strengths of confined walls are determined using this method. These strengths are compared with experimental and other analytical strengths. A sensitivity analysis of the strength is carried out considering different variables. It is concluded that the bidirectional strut method accurately predicts the strength of the walls studied. The main variables that affect the strength are the wall aspect ratio, wall slenderness ratio, and the stiffness of the confining elements.

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