Experimental determination of masonry beam-column behaviour

2001 ◽  
Vol 28 (5) ◽  
pp. 794-803 ◽  
Author(s):  
Yi Liu ◽  
J L Dawe
Keyword(s):  
Single Layer ◽  
Masonry Wall ◽  
Experimental Program ◽  
Masonry Walls ◽  
Test Results ◽  
Eccentricity Ratio ◽  
Design Code ◽  
Concrete Masonry ◽  
Wall Stiffness

An experimental program consisting of 36 reinforced concrete masonry wall specimens comprised of 400 × 200 × 150 mm standard units in two series of tests was carried out to investigate the behaviour of masonry walls under combined axial and lateral loading. W2R series specimens had a single layer of vertical steel, and W4R series specimens had a double layer of vertical steel. Test results show that the effective wall stiffness, (EI)eff, differs from currently specified code values in regions where compression failure tends to predominate. Overall test results presented graphically in the form of lateral load versus deflection, axial load versus moment, and (EI)eff versus eccentricity ratio, e/t, indicate that the current Canadian masonry design code underestimates the effective stiffness of walls with eccentricity ratios e/t < 0.4.Key words: beam–column, masonry, reinforcement, experimental, rigidity, moment magnifier.

Prestressed concrete masonry walls subjected to uniform out-of-plane loading

1993 ◽  
Vol 20 (6) ◽  
pp. 969-979
Author(s):  
J. L. Dawe ◽  
G. G. Aridru
Keyword(s):  
Prestressed Concrete ◽  
Failure Load ◽  
Masonry Walls ◽  
Prestressing Force ◽  
Concrete Masonry ◽  
Ultimate Failure Load ◽  
Wall Stiffness ◽  
Out Of Plane ◽  
Ultimate Failure ◽  
Concrete Masonry Walls

Two series of post-tensioned concrete masonry walls subjected to uniform lateral loading were tested to investigate their flexural strength behaviour. Each series of walls consisted of four full-scale prestressed specimens, with varying levels of prestressing force, and one reinforced specimen. Of particular interest were the load–deflection curves, initial cracking loads, wall stiffness, crack patterns, and ultimate failure loads. An air bag test apparatus was used for applying lateral uniform pressures to the specimens. Results of this experimental investigation showed that, for a given wall thickness, increased prestressing force increases the cracking load, initial wall stiffness, and ultimate failure load. The results have established a linear relationship between increased prestressing force and initial cracking load, initial wall stiffness, and ultimate failure load. The proposed model, which takes into account changes in wall stiffness after initial cracking of the wall, accurately predicts wall behaviour. Key words: masonry, prestressed, walls, strength, behaviour, uniform, pressure, experimental, analytical.

scholarly journals Effect of Roof and Diaphragm Connectivity on Dynamic Behaviour of the PP-band Retrofitted Adobe Masonry Structures

2018 ◽  
Author(s):  
Navaratnarajah Sathiparan
Keyword(s):  
Shaking Table Test ◽  
Masonry Wall ◽  
Shaking Table ◽  
Experimental Program ◽  
Masonry Structures ◽  
Test Results ◽  
Structural Components ◽  
Masonry Unit ◽  
Seismic Safety ◽  
Lateral Drift

This paper discusses the shaking table test results of three PP-band (Polypropylene band) retrofitted quarter scale one-story masonry house models with different roof conditions. Better connections between masonry wall and roof connection are one factor to improve the seismic safety of the masonry houses. Past studies show that PP-band retrofitting improves the integrity of structural components and prevent the collapse of masonry structures during an earthquake. Although the effect of masonry unit type, surface plastering, the pitch of the PP-band mesh, PP-band connectivity in mesh and tightness of the mesh attachment to walls were studied by experiment program, the effect of the roof and its diaphragm connectivity on PP-band retrofitted masonry structure is nonexistent. Therefore, an experimental program was designed and executed for an understanding the effect of the roof and its connection on the dynamic behavior of the PP-band retrofitted box-shaped masonry house models. Results reveal that the PP-band retrofitted models with proper roof diaphragm improves the seismic behavior with respect to lateral drift, shear resistance and ductility.

Analysis of safety of slender concrete masonry walls in relation to CSA S304-14

2019 ◽  
Vol 46 (5) ◽  
pp. 424-438
Author(s):  
Andrea C. Isfeld ◽  
Anna Louisa Müller ◽  
Mark Hagel ◽  
Nigel G. Shrive
Keyword(s):  
Concrete Block ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Effective Height ◽  
Design Standard ◽  
Euler Buckling ◽  
Concrete Masonry ◽  
Reinforced Masonry ◽  
Out Of Plane ◽  
Support Conditions

The Canadian masonry design standard appears to be overly conservative in determining the capacity of concrete block walls with slenderness ratios greater than 30. When assessing the potential for buckling of a masonry wall according to Euler buckling criteria, the effective height is determined in part from the end supports. In Euler theory only pinned, fixed and free support conditions are considered, and the Canadian standard considers the support conditions to be hinged, elastic or stiff. For a partially reinforced masonry wall a true hinged base support is expected to be difficult to achieve, as the width of the concrete block restrains rotation. The effect of the base support conditions on the deflected shape of partially grouted block walls was investigated under axial and out-of-plane loading. The results of this testing were compared with calculations based on the Canadian masonry standard. It becomes clear that the standard is overly conservative in many cases and the design of slender walls needs to be re-examined.

scholarly journals Experimental Investigation into the Seismic Performance of Fully Grouted Concrete Masonry Walls Using New Prestressing Technology

2019 ◽  
Vol 9 (20) ◽  
pp. 4354 ◽  
Author(s):  
Bin Chi ◽  
Xu Yang ◽  
Fenglai Wang ◽  
Zhiming Zhang ◽  
Yuhu Quan
Keyword(s):  
Seismic Performance ◽  
Rural Areas ◽  
Damping Ratio ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Initial Stiffness ◽  
Equivalent Viscous Damping ◽  
Displacement Ductility ◽  
Concrete Masonry ◽  
Section Type

In recent years, traditional masonry structures have been widely used in rural areas of China. However, they were found to have a poor seismic performance during earthquakes. In this study, a new prestressing technology was proposed and described in detail, and it was used in fully grouted concrete masonry wall systems to improve its seismic performance. The experimental work involved investigating the seismic response of four fully grouted reinforced concrete masonry wall systems, consisting of two symmetrically arranged reinforced block masonry walls, with different section types and prestressing technologies, when subjected to cyclic lateral force. Based on the test results, a flexure and ductile failure occurred in the specimens with a rectangular section, while a shear and brittle failure occurred in the specimens with a T-shape section. The prestressing technology had no significant effect on the failure state of the specimens, but it influenced the crack propagation, making cracks fine and densely covered. A symmetrical and obvious pinching effect was observed in the hysteretic response of all specimens. The average displacement ductility of the specimens varied within a range of values between 3.34 and 6.92, according to the section type of the specimens, and the prestressing technology improved the displacement ductility of the specimens. Moreover, the prestressing technology significantly improved the initial stiffness of the specimens, and the specimens with prestressing technology experienced a greater fall in the degradation of the normalized stiffness than the specimens without this technology throughout the loading process. In addition, the equivalent viscous damping of the specimens ranged between 8.2% and 10.8%, according to the section type. It could be concluded that the prestressing technology improved the energy dissipation of the specimens at the ascending stage, although it had no marked influence on the equivalent damping ratio of the specimens.

Strengthening of a concrete masonry wall subject to lateral load with sprayed glass-fibre-reinforced polymer

2010 ◽  
Vol 37 (10) ◽  
pp. 1315-1330 ◽  
Author(s):  
M. A. Haddad ◽  
E. Shaheen ◽  
G. A. Parsekian ◽  
D. Tilleman ◽  
N. G. Shrive
Keyword(s):  
Glass Fibre ◽  
Lateral Load ◽  
Masonry Wall ◽  
Masonry Walls ◽  
Reinforced Polymer ◽  
Concrete Masonry ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Failure Line

Unreinforced hollow concrete masonry walls could be used to construct basements if strengthened to resist the lateral load. Two face-shell-bedded concrete masonry walls were constructed, 3 m high by 6 m long. As a simple strengthening technique, one wall was sprayed with glass-fibre-reinforced polymer (GFRP) on one side to a nominal average thickness of 5 mm. The walls were subjected to distributed point loading simulating increasing pressure from top to bottom of the wall. Support conditions were applied to simulate the walls being part of a basement. The plain wall failed with a failure line cracking pattern at a lateral load of 44 kN. The sprayed wall failed in a much more brittle fashion when the load reached 330 kN. The GFRP suffered a mode III tear at the bottom course. The results indicate that spraying a plain masonry wall with GFRP increases its ability to resist lateral load considerably, and that the process could be improved in terms of both the thickness of the layer and the area of wall covered to achieve a specific target. The two walls were analyzed using the yield-line, fracture-line, and failure-line methods. The failure-line method was improved by accounting for the stiffness orthotropy of masonry and gave the most accurate prediction of these plastic design methods. A finite element model of the masonry provided the most accurate prediction of capacity.

Study on the explosion-proof performance of polyurea-reinforced masonry walls with different spraying methods

2019 ◽  
Author(s):  
Wei Shang ◽  
Xu-dong Zu ◽  
Zheng-xiang Huang ◽  
Wen-ni Shen
Keyword(s):  
Masonry Wall ◽  
Blast Waves ◽  
Impact Fracture ◽  
Back Surface ◽  
Masonry Walls ◽  
Test Results ◽  
Contact Explosion ◽  
Reinforced Masonry ◽  
Theoretical Predictions ◽  
The Impact

Abstract Based on the propagation theory of blast waves and the strain rate effect of polyurea, the explosion-proof performance of polyurea-reinforced masonry walls with different spraying methods is discussed in this paper. The impact fracture of masonry walls after contact explosion was analyzed, and the fracture results of a blast wave on polyurea-reinforced masonry walls with different spraying methods were predicted. Furthermore, explosion-proof experiments of a standard masonry wall (2m×1.2m×0.37m) under three conditions including non-sprayed, back surface sprayed polyurea and double-sided sprayed polyurea were carried out to verify the theoretical predictions. Finally, the impact fracture results of standard masonry walls after a 1 kg TNT contact explosion under the three conditions were obtained. The test results were in good agreement with the theoretical predictions. It clearly demonstrated that polyurea coating can significantly improve the explosion-proof performance of masonry walls, and double-sided sprayed showed better explosion-proof performance than back surface sprayed at the same coating thickness.

Experimental Research on the Seismic Behavior of Enclosing Masonry Walls Simulated the Structure of an Ancient Masonry Pagoda Strengthened with Steel Straps

2013 ◽  
Vol 353-356 ◽  
pp. 1885-1891
Author(s):  
Sheng Cai Li ◽  
Meng Ji Hu ◽  
Yong Qian
Keyword(s):  
Seismic Performance ◽  
Control Process ◽  
Single Layer ◽  
Masonry Wall ◽  
Shear Capacity ◽  
Operating Conditions ◽  
Masonry Walls ◽  
Restoring Force ◽  
Static Test ◽  
Wall Models

in this paper, four single-layer masonry wall models in1/8 scale were made by a kind of special bricks on the basis of an ancient masonry pagoda structure. The models are divided into two groups by whether there is a masonry floor in a model or not. Pseudo-static test is introduced to study the seismic performance of four models with a special load control process which is suited to masonry structure. According to the test results, the horizontal bearing capacity and ductility of each masonry walls reinforced with steel straps under horizontal low cyclic loading has been sorted out. Four nonlinear restoring force models are inferred from the experimental results and phenomena under various operating conditions. And the shear capacity calculation formula of reinforced masonry wall models is fit out. The theory and experimental study show that seismic performance of the masonry pagodas strengthened with steel straps has been improved significantly.

Reliability Analysis on Shear Capacity of Reinforced Masonry Wall Due to Earthquake

2011 ◽  
Vol 105-107 ◽  
pp. 360-365
Author(s):  
Liang Li Xiao ◽  
Xiao Tao Wang ◽  
Yue Li ◽  
William M. Bulleit
Keyword(s):  
Structural Reliability ◽  
Limit State ◽  
State Equation ◽  
Masonry Wall ◽  
Shear Capacity ◽  
Structural Safety ◽  
Masonry Walls ◽  
Load Effect ◽  
Concrete Masonry ◽  
Shear Bearing Capacity

A probabilistic model is used to assess the structural reliability of typical reinforced concrete masonry walls under combined shear and compression. Factors such as model error, shear strength of concrete masonry, wall aspect ratio, horizontal and vertical reinforcement ratios, structural safety class, axial load-to-dead ratio, height and thickness radio of the wall, and load effect combination will be considered. Based on a relatively large number of test results and theoretical analysis from the literature, the limit state equation for shear bearing capacity was established. A sensitivity analysis will be performed to identify the key contributors to the reliability of the masonry walls under the combination of gravity and earthquake. The results will provide a base to evaluate whether consistent safety is achieved for masonry walls that are subjected to different load combinations. The counteracting load factors in current design codes for masonry structure will be investigated.

CARINA: A New Project to Extend the Data Base for Fracture Mechanical Characteristics of Irradiated German RPV Materials at High Neutron Fluences

2009 ◽  
Author(s):  
Hieronymus Hein ◽  
Jens Ganswind ◽  
Arnulf Gundermann ◽  
Elisabeth Keim ◽  
Hilmar Schnabel
Keyword(s):  
Data Base ◽  
Master Curve ◽  
Current Status ◽  
Experimental Program ◽  
Test Results ◽  
Neutron Fluences ◽  
New Research ◽  
High Neutron ◽  
Specific Impact

Within the recently finished project CARISMA “Determination of Fracture Mechanics Values on Irradiated Specimens of German PWR Plants” a data base was created for pre-irradiated original RPV steels of the four construction lines of German PWRs, which allowed to examine the consequences if the Master Curve (T0) approach instead of the RTNDT concept is applied for the RPV safety assessment. In the new research project CARINA the experimental data base for both the safety concepts RTNDT and Master Curve for the proof against RPV brittle fracture will be extended by additional representative materials irradiated under different conditions and with respect to the accumulated neutron fluences and specific impact parameters (neutron flux, chemical composition, manufacturing effects). The investigation of materials irradiated to higher neutron fluences and different irradiation conditions complements the representativeness of the conclusions for the applicability of safety concepts to RPVs with longer operation times and beyond EoL respectively in terms of “Upper Bound” coverage. The obtained results will be evaluated on the basis of the already elaborated approaches and will be represented by the aid of the Master Curve concept in an appropriate way. An overview on the objectives, the experimental program, and the current status of the project is given. Finally first test results are presented and evaluated.

scholarly journals Experimental in-plane performance of insulated concrete and brick masonry wall panels retrofitted using polymer composites

2018 ◽  
Vol 51 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Najif Ismail ◽  
Tamer El-Maaddawy ◽  
Amanullah Najmal ◽  
Nouman Khattak
Keyword(s):  
Single Layer ◽  
Masonry Wall ◽  
Brick Masonry ◽  
Experimental Program ◽  
Reinforced Concrete Frame ◽  
Infill Walls ◽  
Concrete Frame ◽  
Strain Behaviour ◽  
Ductility Capacity ◽  
Strength Increment

Masonry infilled reinforced concrete frame buildings built prior to the introduction of modern seismic provisions have been observed to undergo damage in and around the masonry infill walls during most recent moderate to severe earthquakes. Fibre reinforced cementitious matrix (FRCM) is one of several retrofitting options available to limit such earthquake induced damage to infill walls. An experimental program was undertaken herein to experimentally investigate the effectiveness of FRCM as a strengthening solution for vintage (i.e. built between 1880 and 1930) un-reinforced brick masonry (URM) and insulated concrete masonry (IMU) infill walls. A total of 16 masonry assemblages were tested under in-plane diagonal load, of these 8 were constructed replicating vintage URM whereas the remainder were constructed using modern IMU. IMU is a preferred masonry type in hot and humid regions owing to its superior insulting capability. Different polymer fabrics (i.e., carbon, glass and basalt) were applied over both faces of test walls, with two replicate test walls receiving the same FRCM strengthening details. One test wall of each masonry type was tested as-built to serve as a control specimen for comparison. One wall of each masonry type received two layers of basalt FRCM. The investigated aspects included stress-strain behaviour, stiffness, and ductility. Shear strength increment observed due to single layer of FRCM application was 422-778% for vintage URM and 307-415% for modern IMU. FRCM also substantially increased the ductility capacity of the masonry assemblages.

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