The design of plain masonry walls

1980 ◽  
Vol 7 (2) ◽  
pp. 233-242 ◽  
Author(s):  
Jose Ojinaga ◽  
Carl J. Turkstra

This paper presents a practical method to determine the ultimate strength of plain brick or concrete block masonry walls. Results given by the proposed method are compared with a more rigorous analytical solution, with published test data, and with the current Canadian design code for masonry. Means and coefficients of variation as well as distribution shapes of the ratio of test to predicted loads are estimated from experimental data. Design procedures and simplifications along with two examples are presented.

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Hui Su ◽  
Dongyue Wu ◽  
Mengying Shen ◽  
Wei Chen ◽  
Shilin Wang

To improve the thermal performance of external masonry walls, a new tenon composite block is proposed as the external maintenance component which contains the internal hollow concrete block part, the external block part, and the extruded polystyrene layer fixed by tenons. The production process and concrete material mixing ratio were optimized for the new tenon composite block to promote its application. The mechanical strength and thermal properties of the optimized tenon composite blocks were tested with experiments and numerical simulation in this study. The testing and simulation results indicated that after utilizing the two optimized concrete mixing ratios, the tenon composite block strength matched the strength requirements according to the related design code. The thermal performance of the tenon composite block wall was also good compared with that of a common block wall.


Author(s):  
Klaus Medeiros ◽  
Kyle Chavez ◽  
Fernando S. Fonseca ◽  
Guilherme Parsekian ◽  
Nigel G. Shrive

Finite element models were developed to assess the influence of several parameters on the load capacity, deflection, and initial stiffness of multi-story, partially grouted masonry walls with openings. The base model was validated with experimental data from three walls. The analyses indicated that the load capacity of masonry walls was considerably sensitive to the ungrouted and grouted masonry strengths and mortar shear strength; moderately sensitive to the vertical reinforcement ratio and aspect ratio; slightly sensitive to the axial stress; and almost insensitive to the opening size, reinforcement spacing, and horizontal reinforcement ratio. The deflection of the walls had well-defined correlations with the masonry strength, vertical reinforcement, axial stress and aspect ratio. The initial stiffness was especially sensitive to the axial stress and the aspect ratio, but weakly correlated with the opening size, and the spacing and size of the reinforcement.


2021 ◽  
Vol 881 ◽  
pp. 149-156
Author(s):  
Mochamad Teguh ◽  
Novi Rahmayanti ◽  
Zakki Rizal

Building material innovations in various interlocking concrete block masonry from local materials to withstand lateral earthquake forces is an exciting issue in masonry wall research. The block hook has an advantage in the interlocking system's invention to withstand loads in the in-plane and out-of-plane orientations commonly required by the masonry walls against earthquake forces. Reviews of the investigation of in-plane and out-of-plane masonry walls have rarely been found in previous studies. In this paper, the results of a series of experimental tests with different interlocking models in resisting the simultaneous in-plane shear and out-of-plane bending actions on concrete blocks are presented. This paper presents a research investigation of various interlocking concrete blocks' mechanical properties with different hook thicknesses. Discussion of the trends mentioned above and their implications towards interlocking concrete block mechanical properties is provided.


1990 ◽  
Vol 112 (2) ◽  
pp. 441-450 ◽  
Author(s):  
A. Sakurai ◽  
M. Shiotsu ◽  
K. Hata

Experimental data of pool film boiling heat transfer from horizontal cylinders in various liquids such as water, ethanol, isopropanol, Freon-113, Freon-11, liquid nitrogen, and liquid argon for wide ranges of system pressure, liquid subcooling, surface superheat and cylinder diameter are reported. These experimental data are compared with a rigorous numerical solution and an approximate analytical solution derived from a theoretical model based on laminar boundary layer theory for pool film boiling heat transfer from horizontal cylinders including the effects of liquid subcooling and radiation from the cylinder. A new correlation was developed by slightly modifying the approximate analytical solution to agree better with the experimental data. The values calculated from the correlation agree with the authors’ data within ± 10 percent, and also with other researchers’ data for various liquids including those with large radiation effects, though these other data were obtained mainly under saturated conditions at atmospheric pressure.


2021 ◽  
Vol 2057 (1) ◽  
pp. 012007
Author(s):  
A I Kadyirov ◽  
E K Vachagina

Abstract A semi-analytical solution to the problem of the steady flow of viscoelastic single equation eXended Pom-Pom (XPP) fluid in a round pipe using the four-mode rheological equation of state of XPP is presented. An original parametric method for solving the set problem is used. The resulting method is applicable for solving a similar problem in a flat slit. The developed solution method is tested by comparing it with numerical results and experimental data. Using a polyacrylamide solution as an example, the influence of the Weissenberg number on the axial velocity profiles and the components of normal stresses is studied.


Author(s):  
R G Dong ◽  
D E Welcome ◽  
J Z Wu

This study generally hypothesized that the vibration-induced biodynamic stress and number of its cycles in a substructure of the hand-arm system play an important role in the development of vibration-induced disorders in the substructure. As the first step to test this hypothesis, the specific aims of this study were to develop a practical method to quantify the biodynamic stress-cycle measure, to compare it with ISO-weighted and unweighted accelerations, and to assess its potential for applications. A mechanical-equivalent model of the system was established using reported experimental data. The model was used to estimate the average stresses in the fingers and palm. The frequency weightings of the stresses in these substructures were derived using the proposed stress-cycle measure. This study found the frequency dependence of the average stress distributed in the fingers is different from that in the palm. Therefore, this study predicted that the frequency dependencies of finger disorders could also be different from those of the disorders in the palm, wrist, and arms. If vibration-induced white finger (VWF) is correlated better with unweighted acceleration than with ISO-weighted acceleration, the biodynamic stress distributed in the fingers is likely to play a more important role in the development of VWF than is the biodynamic stress distributed in the other substructures of the hand-arm system. The results of this study also suggest that the ISO weighting underestimates the high-frequency effect on the finger disorder development but it may provide a reasonable risk assessment of the disorders in the wrist and arm.


Author(s):  
Seong Kuk Cho ◽  
Jekyoung Lee ◽  
Jeong Ik Lee ◽  
Jae Eun Cha

A Sodium-cooled Fast Reactor (SFR) has receiving attention as one of the promising next generation nuclear reactors because it can recycle the spent nuclear fuel produced from the current commercial nuclear reactors and accomplish higher thermal efficiency than the current commercial nuclear reactors. However, after shutdown of the nuclear reactor core, the accumulated fission products of the SFR also decay and release heat via radiation within the reactor. To remove this residual heat, a decay heat removal system (DHRS) with supercritical CO2 (S-CO2) as the working fluid is suggested with a turbocharger system which achieves passive operational capability. However, for designing this system an improved S-CO2 turbine design methodology should be suggested because the existing methodology for designing the S-CO2 Brayton cycle has focused only on the compressor design near the critical point. To develop a S-CO2 turbine design methodology, the non-dimensional number based design and the 1D mean line design method were modified and suggested. The design methodology was implemented into the developed code and the code results were compared with existing turbine experimental data. The data were collected under air and S-CO2 environment. The developed code in this research showed a reasonable agreement with the experimental data. Finally using the design code, the turbocharger design for the suggested DHRS and prediction of the off design performance were carried out. As further works, more effort will be put it to expand the S-CO2 turbine test data for validating the design code and methodology.


2018 ◽  
Vol 9 (3) ◽  
pp. 281-295 ◽  
Author(s):  
Patricia Raposo ◽  
André Furtado ◽  
António Arêde ◽  
Humberto Varum ◽  
Hugo Rodrigues

Purpose The infill masonry walls in recent worldwide earthquakes have shown that it is necessary to conduct further studies to characterize the behavior of existing buildings and, in particular, of infill masonry walls under seismic activity. The lack of characterization studies of infill walls made by concrete blocks justifies the investigation reported herein, which includes experimental tests on sample sets to evaluate the mechanical properties of masonry components (units and mortar) and assemblages (wallets) made with masonry units from Faial. For the later, normal compressive, diagonal tensile/shear and out-of-plane flexural strengths were obtained according to standard procedures, the results of which are presented in the manuscript. The paper aims to discuss these issues. Design/methodology/approach One experimental campaign was conducted with the aim to mechanically characterize concrete blocks masonry samples. Several experimental tests were carried out in full-scale masonry concrete wallets according to the constructive methodology used. Findings Based on the data obtained from the mechanical characterization tests of the concrete masonry blocks, it can be seen that under simple compression, the masonry specimens’ average resistance is about 6 times superior than the average resistance to diagonal shear/tension, while the stiffness is almost doubled. In simple compression tests, it was observed that the masonry specimens cracked in areas of higher drilling of the blocks. In the tensile tests by diagonal compression, it was found that the test specimens were mainly fissured by the block/mortar joint interfaces, following the delineation of settlement and top joints. Originality/value There are no experimental results available in the literature for this type of bricks that can contribute to the development of numerical studies.


2007 ◽  
Vol 44 (02) ◽  
pp. 93-105
Author(s):  
Jeom Kee Paik

To study the accuracy of simplified formulations for prediction of the ultimate strength of longitudinally stiffened panels under uniaxial compression, the preferred approach is to compare them with available experimental data or numerical results from more sophisticated analysis procedures. Such studies are necessary in the development of both design code calibrations and reliability analysis procedures. Existing experimental data and numerical results useful for this purpose are first collected. Salient features of existing design formulations for compressive strength are then reviewed. Selected formulations are compared with the experimental data/numerical results. It is illustrated that there can be a significant amount of scatter in strength estimates by any one formulation and among formulations. The reasons for such scatter are discussed, with the emphasis on the collapse mode(s) involved, the effective width of plating, initial imperfections, and rotational restraints due to stiffening. The experimental and numerical strength data collected are documented for convenience of future use by other investigators.


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