scholarly journals Design rules for hollow concrete masonry walls subjected to concentrated loads

2003 ◽  
Vol 30 (1) ◽  
pp. 203-211 ◽  
Author(s):  
Junyi Yi ◽  
Nigel G Shrive
Keyword(s):  
Experimental Studies ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Concentrated Loads ◽  
Wall Width ◽  
Concentrated Load ◽  
Design Rules ◽  
Plate Length ◽  
Concrete Masonry ◽  
Concrete Masonry Walls

Design rules are proposed for assessing the bearing strengths of hollow concrete masonry walls subjected to in-plane concentrated loads. These are derived from numerical and experimental studies of this problem. Two possible zones of failure are considered: the solid–grouted masonry directly beneath the concentrated loads, and the hollow masonry beneath the grouted portion. The important factors influencing the bearing strength are taken into account: loading eccentricity across the wall width, effective loading area, loading plate length, and loading location along the wall. An angle of 22° or slope (vertical to horizontal) of 2.5:1 is chosen for a safe estimate of the dispersion of concentrated load through the solid–grouted masonry. For partial grouting patterns, at least two courses downward should be grouted to a length compatible with the loading plate. When compared with the available numerical and experimental results, conservative estimates of ultimate strength are obtained in all cases.Key words: design rules, hollow concrete masonry wall, in-plane concentrated load, out-of-plane eccentricities, loading plate length, loading locations, dispersion angle.

Behaviour of hollow concrete masonry walls with one-course bond beams subjected to concentric and eccentric concentrated loading

2003 ◽  
Vol 30 (1) ◽  
pp. 181-190 ◽  
Author(s):  
Junyi Yi ◽  
Nigel G Shrive
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Three Dimensional ◽  
Masonry Walls ◽  
Finite Element Models ◽  
Concentrated Load ◽  
Concrete Masonry ◽  
Out Of Plane ◽  
Concentrated Loading ◽  
Concrete Masonry Walls

Three-dimensional finite element models of unreinforced hollow concrete masonry walls with one-course bond beams subjected to concentrated loading have been analyzed. The walls were modelled with different loading plate sizes, different loading locations along the wall (at the midpoint of the wall, at the end of the wall, and between these points), and different out-of-plane eccentricities (e = 0, t/6, and t/3). The hollow block units, mortar, grout, and bond beam blocks in the walls were modelled separately. Both smeared and discrete cracking methods have been utilized for predicting cracking under load. Geometric and material nonlinearities and damage due to progressive cracking were taken into account in the analyses. The predicted failure modes and ultimate capacities of the walls with the concentric concentrated load applied at the midpoint or at the end of the wall compared very well with the experimental results. When the load was between the midpoint and the end of the wall, the predicted ultimate capacity was between those for the load at the midpoint and at the end. The strength of the walls decreases with increasing out-of-plane eccentricities.Key words: finite element models, hollow masonry, smeared and discrete cracking models, concentrated load, loading locations, out-of-plane eccentricities.

Behaviour of partially grouted hollow concrete masonry subjected to concentrated loads

2003 ◽  
Vol 30 (1) ◽  
pp. 191-202 ◽  
Author(s):  
Junyi Yi ◽  
Nigel G Shrive
Keyword(s):  
Wall Thickness ◽  
Masonry Walls ◽  
Concentrated Loads ◽  
Concentrated Load ◽  
Strength Variation ◽  
Concrete Masonry ◽  
Testing Programme ◽  
Experimental Programme ◽  
The Face ◽  
Hollow Block

An experimental programme was performed to study the behaviour of hollow concrete masonry wallettes with bond beams and vertical columns of grout subjected to concentrated loads. Forty-three wallettes were tested, with concentrated loads being applied either concentrically or eccentrically, through various-sized loading plates above the grout columns or on the bond beams above the hollow blocks. When the concentrated load was applied above the grout columns, the face shells of the hollow block units attached to the grout columns split and the columns subsequently crushed. When the load was applied on the bond beams, wallettes failed similarly to hollow masonry walls without vertical columns of grout, with web splitting and vertical cracking in line with the load, followed by face-shell spalling and (or) mortar crushing. When the eccentricity was one third of the wall thickness, failure was dominated by local spalling beneath the loading plate. The testing programme and mechanisms of failure are described, together with strength variation with increasing eccentricity, and dispersion of the concentrated load through the bond beam. General implications for the design of hollow concrete masonry with bond beams and vertical columns of grout subjected to concentrated loads are discussed.Key words: hollow concrete masonry, bond beam, grout columns, concentrated load, concentric, eccentric.

In-plane flexural strength of unbonded post-tensioned concrete masonry walls

2017 ◽  
Vol 136 ◽  
pp. 245-260 ◽  
Author(s):  
Reza Hassanli ◽  
Mohamed A. ElGawady ◽  
Julie E. Mills
Keyword(s):  
Flexural Strength ◽  
Masonry Walls ◽  
Concrete Masonry ◽  
Concrete Masonry Walls ◽  
Post Tensioned

scholarly journals Behavior of Partially Grouted Concrete Masonry Walls under Quasi-Static Cyclic Lateral Loading

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2424
Author(s):  
Sebastián Calderón ◽  
Laura Vargas ◽  
Cristián Sandoval ◽  
Gerardo Araya-Letelier
Keyword(s):  
Shear Strength ◽  
Aspect Ratio ◽  
Load Capacity ◽  
Masonry Walls ◽  
Lateral Stiffness ◽  
Edge Elements ◽  
Vertical Reinforcement ◽  
Concrete Masonry ◽  
Resistance Degradation ◽  
Concrete Masonry Walls

Eight partially grouted (PG-RM) concrete masonry walls were tested to study the influence of the strength and width of blocks, the wall aspect ratio, the horizontal and vertical reinforcement ratio, and the presence of edge elements (flanges). The results were analyzed in terms of the failure mode, damage progression, shear strength, lateral stiffness degradation, equivalent viscous damping ratio, and displacement ductility. Additionally, the performances of some existing shear expressions were analyzed by comparing the measured and predicted lateral load capacity of the tested walls. Based on the results, a slight increment in the lateral stiffness was achieved when employing stronger blocks, while the shear strength remained constant. Besides, increasing the width of concrete blocks did not have a significant effect on the shear strength nor in the initial tangential stiffness, but it generated a softer post-peak strength degradation. Increasing the wall aspect ratio reduced the brittleness of the response and the shear strength. Reducing the amount of vertical reinforcement lowered the resulting shear strength, although it also slowed down the post-peak resistance degradation. Transversal edge elements provided integrity to the wall response, generated softer resistance degradation, and improved the symmetry of the response, but they did not raise the lateral resistance.

scholarly journals Experimental and numerical analysis on the structural fire behaviour of three-cell hollowed concrete masonry walls

2021 ◽  
Vol 228 ◽  
pp. 111439
Author(s):  
Rafael G. Oliveira ◽  
João Paulo C. Rodrigues ◽  
João Miguel Pereira ◽  
Paulo B. Lourenço ◽  
Rúben F.R. Lopes
Keyword(s):  
Numerical Analysis ◽  
Masonry Walls ◽  
Fire Behaviour ◽  
Structural Fire ◽  
Concrete Masonry ◽  
Concrete Masonry Walls
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