scholarly journals Analysis of uniaxial compression behavior of hollow concrete block masonry: experimental and analytical approaches

2020 ◽  
Vol 71 (7) ◽  
pp. 802-813
Author(s):  
Loan Bui Thi
Keyword(s):  
Uniaxial Compression ◽  
Failure Modes ◽  
Concrete Block ◽  
Brick Masonry ◽  
Compression Tests ◽  
Compression Behavior ◽  
Compression Load ◽  
Hollow Brick ◽  
Analytical Approaches ◽  
Masonry Prism

This article focuses on the uniaxial compression behavior of concrete hollow brick masonry assembly. This study was performed both by experimental and analytical approaches. In the first experimental part, the compression tests were done according to the European standard EN1052-1. It is highlighted from the tests that this concrete hollow brick masonry is a very high dispersive material and that the compression behavior of this masonry is similar and depends principally on that of bricks. In addition, the vertical splitting failure modes reflect the effect of "expanding/restraining" for this type of masonry and the elastic properties determined from these tests are comparable with the values found in the literature. Then, in the analytical approach, the simple calculations were done by different existed models to predict the compressive strength of masonry prism. A comparison of the results obtained by using these models with those of experimentation shows that only the model which takes into account the effect of vertical joints is mostly adapted for the safe design of this masonry prism under uniaxial compression load.

Analysis of uniaxial compression behavior of hollow concrete block masonry: experimental and analytical approaches

2020 ◽  
Vol 71 (7) ◽  
pp. 802-813
Author(s):  
Loan Bui Thi
Keyword(s):  
Uniaxial Compression ◽  
Failure Modes ◽  
Concrete Block ◽  
Brick Masonry ◽  
Compression Tests ◽  
Compression Behavior ◽  
Compression Load ◽  
Hollow Brick ◽  
Analytical Approaches ◽  
Masonry Prism

This article focuses on the uniaxial compression behavior of concrete hollow brick masonry assembly. This study was performed both by experimental and analytical approaches. In the first experimental part, the compression tests were done according to the European standard EN1052-1. It is highlighted from the tests that this concrete hollow brick masonry is a very high dispersive material and that the compression behavior of this masonry is similar and depends principally on that of bricks. In addition, the vertical splitting failure modes reflect the effect of "expanding/restraining" for this type of masonry and the elastic properties determined from these tests are comparable with the values found in the literature. Then, in the analytical approach, the simple calculations were done by different existed models to predict the compressive strength of masonry prism. A comparison of the results obtained by using these models with those of experimentation shows that only the model which takes into account the effect of vertical joints is mostly adapted for the safe design of this masonry prism under uniaxial compression load.

scholarly journals An Experimental Study of Compression Behavior of Warp-knitted Spacer Fabric

2014 ◽  
Vol 9 (2) ◽  
pp. 155892501400900
Author(s):  
Yanping Liu ◽  
Hong Hu
Keyword(s):  
Experimental Study ◽  
Displacement Curve ◽  
Compression Tests ◽  
Compression Behavior ◽  
Compression Load ◽  
Fabric Structure ◽  
Spacer Fabric ◽  
Compression Mechanism ◽  
Impact Protection ◽  
Spacer Fabrics

This paper presents an experimental study of the compression behavior of a typical warp-knitted spacer fabric which is specially developed as a cushioning material for human body protection. The fabric has a highly heterogeneous and discontinuous structure and exhibits a complicated compression behavior. Different test boundary conditions and sample sizes were first adopted to conduct compression tests of the fabric. Then, the compression behavior of the fabric was analyzed based on its compression load-displacement curve obtained under a selected test condition. The potential compression mechanism of the fabric was identified with support of the image analysis of the fabric structure at different compression stages. The study provides some useful information for designing warp-knitted spacer fabrics for impact protection.

scholarly journals Experimental Study on Acoustic Emission Characteristics of Dry and Saturated Basalt Columnar Joints under Uniaxial Compression and Tensile Damage

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Liu Gang ◽  
Xiao Fu-kun ◽  
Cheng Qian-long ◽  
Qin Tao
Keyword(s):  
Experimental Study ◽  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Failure Modes ◽  
Compression Tests ◽  
Steady Growth ◽  
Columnar Joints ◽  
Ae Location ◽  
Location Map ◽  
Tensile Damage

An experimental study was carried out to investigate the acoustic emission (AE) characteristics of dry and saturated basalt columnar joints under uniaxial compression and tensile damage by using the TAW-2000 rock experiment system and SH-IIAE system for the whole loading. The results show that the softening coefficient of uniaxial compressive strength and the tensile strength was 0.78 and 0.68, respectively, and water increases the sample complexity and has a strong effect on its strength. The dry sample under uniaxial compression at the beginning of loading produced a large number of AE signals, and the AE signal showed steady growth as the load increased, but the sample destruction occurred during the blank period, which can be used as a precursor of instability. From the amplitude-time-energy diagram, it can be found that as amplitude increases with hit, energy decreases, which shows an obvious triangle relation. From the uniaxial compression damage AE location map, we can find that AE events exist disorderly and show scattered distribution in each area. From the failure modes and sections of tension and uniaxial compression tests, it is found that there are many layers and fissures in rock samples, which are consistent with AE location.

Can Textile Reinforced Mortar (TRM) Systems Be Really Effective to Increase Compressive Strength of Masonry Panels?

2019 ◽  
Vol 817 ◽  
pp. 435-441 ◽  
Author(s):  
Jacopo Donnini ◽  
Gianluca Maracchini ◽  
Gianluca Chiappini ◽  
Valeria Corinaldesi ◽  
Enrico Quagliarini ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Failure Modes ◽  
Brick Masonry ◽  
Masonry Walls ◽  
Total Thickness ◽  
Compression Tests ◽  
Clay Brick ◽  
Experimental Campaign ◽  
Simple Compression ◽  
Textile Reinforced Mortar

The use of Textile Reinforced Mortar (TRM) systems represent a valid alternative to traditional strengthening techniques, to improve mechanical strength and seismic performance of masonry buildings. Their effectiveness has been validated by several studies [1-4]. However, the TRM contribution in the mechanical behavior of masonry walls, subjected to simple compression, has not yet been fully investigated. In this study, an experimental campaign with the objective of studying the efficiency of TRM systems, applied to clay brick masonry panels, is presented. Compression tests were conducted on clay brick masonry panels with dimensions of 250x1000x1200 mm3. Glass fiber bidirectional fabrics were applied on both sides of the panels, coupled with lime-based mortar, and connected with stainless steel helical connectors. The total thickness of the reinforcement system is 30 mm. The effect of the TRM reinforcement on the mechanical behavior of the panel is analyzed and experimental results are compared with those of unreinforced panels in terms of ultimate strength and failure modes.

scholarly journals Mechanical analysis and failure modes prediction of composite rock under uniaxial compression

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jianguang Li ◽  
Zhuoqun Yu ◽  
Ziyi Zhou ◽  
Yanchun Wang ◽  
Jiwei Li
Keyword(s):  
Mechanical Properties ◽  
Stress Distribution ◽  
Uniaxial Compression ◽  
Construction Projects ◽  
Failure Modes ◽  
Mechanical Analysis ◽  
Compression Tests ◽  
Wide Range ◽  
Potential Failure ◽  
Thin Interlayer

AbstractComposite rocks are easily encountered in a wide range of geotechnical construction projects. Understanding their mechanical properties and failure modes is very important to ensure project quality and safety. This study conducted a mechanical analysis to assess the stress distribution in composite rock with a horizontal interlayer and predicted the possible failure modes. Uniaxial compression tests were carried out on the composite rock samples to reveal their mechanical properties. It was concluded that a composite rock with a thick interlayer failed more easily than a composite rock with a thin interlayer. Four potential failure modes were related to the internal stress distribution under compression and the differences in deformation capacity and strength among the constituent components. The stress distribution derived from the mechanical analysis could explain the failure mechanism very well. These results verified the validity of the mechanical analysis results and improved understanding of the mechanical properties of composite rock with a horizontal interlayer.

scholarly journals Experimental Investigation of Progressive Failure Processes Using 3D Acoustic Emission Tomography

2021 ◽  
Vol 9 ◽  
Author(s):  
Yan Cheng ◽  
Paul Hagan ◽  
Rudrajit Mitra ◽  
Shuren Wang ◽  
Hong-Wei Yang
Keyword(s):  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Failure Modes ◽  
Progressive Failure ◽  
Three Dimensional ◽  
Stress Conditions ◽  
Compression Tests ◽  
Tomographic Images ◽  
Fracture Development ◽  
Ae Counts

In this paper, the potential of 3D acoustic emission (AE) tomography technique in demonstrating fracture development and delineating stress conditions was examined. Brazilian tests and uniaxial compression tests were monitored by 3D AE tomography. AE counts, AE source locations and 3D tomographic images of locally varying velocity distributions were analyzed along with stress and strain measurements. Experimental results revealed two distinct failure processes between Brazilian tests and uniaxial compression tests indicated by differences in AE counts, source locations and the temporal variation of velocity. Furthermore, the development of micro-cracks showed by the results correlated well with theoretical analysis and experimental observations. Additionally, stress patterns, failure modes and final failure planes were indicated by AE locations and velocity tomography. Three-dimensional velocity tomographic images indicated the anisotropy of samples caused by stresses as well. These results confirm the usefulness of AE tomography as a method to monitor stress induced failure and the potential of AE tomography for delineating stress conditions and predicting rock failure.

scholarly journals Strength Enhancement of Interlocking Hollow Brick Masonry Walls with Low-Cost Mortar and Wire Mesh

2021 ◽  
Vol 6 (12) ◽  
pp. 166
Author(s):  
Panuwat Joyklad ◽  
Nazam Ali ◽  
Muhammad Usman Rashid ◽  
Qudeer Hussain ◽  
Hassan M. Magbool ◽  
...  
Keyword(s):  
Failure Modes ◽  
Ultimate Load ◽  
Cement Mortar ◽  
Low Cost ◽  
Brick Masonry ◽  
Wire Mesh ◽  
Masonry Walls ◽  
Structural Behaviour ◽  
Hollow Brick ◽  
Strength And Ductility

Cement–clay Interlocking Hollow Brick Masonry (CCIHBM) walls are characterized by poor mechanical properties of bricks and mortar. Their performance is observed to be unsatisfactory under both gravity and seismic loads. There is an urgent need to develop sustainable, environmentally friendly, and low-cost strengthening materials to alter the structural behaviour of brick masonry walls in terms of strength and ductility. The results of an experimental investigation conducted on the diagonal compressive response of CCIHBM walls are presented in this study. In this experimental study, a total of six CCIHBM walls were constructed using cement–clay interlocking hollow bricks. One was tested as a control or reference wall, whereas the remaining walls were strengthened using cement mortar. In some walls, the cement mortar was also combined with the wire mesh. The research parameters included the type of Ordinary Portland Cement (OPC) (Type 1 and Type 2), thickness of cement mortar (10 mm and 20 mm), and layers of wire mesh (one and three layers). The experimental results indicate that control or unstrengthened CCIHBM walls failed in a very brittle manner at a very low ultimate load and deformation. The control CCIHBM wall, i.e., W-CON, failed at an ultimate load of 247 kN, and corresponding deflection was 1.8 mm. The strength and ductility of cement mortar and wire mesh-strengthened walls were found to be higher than the reference CCIHBM wall. For example, the ultimate load and deformation of cement-mortar-strengthened wall were found to be 143% and 233% higher than the control wall, respectively. Additionally, the ultimate failure modes of cement mortar and wire mesh strengthened were observed as ductile as compared to the brittle failure of reference wall or unstrengthened CCIHBM wall, which increased by 66% and 150% as compared with the control wall.

scholarly journals Experimental Study on Infrared Temperature Characteristics and Failure Modes of Marble with Prefabricated Holes under Uniaxial Compression

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 713
Author(s):  
Yanyan Peng ◽  
Qunchao Lin ◽  
Manchao He ◽  
Chun Zhu ◽  
Haijiang Zhang ◽  
...  
Keyword(s):  
Uniaxial Compression ◽  
Failure Modes ◽  
Rock Sample ◽  
Vertical Axis ◽  
Maximum Temperature ◽  
Thermal Imager ◽  
Infrared Thermal Imaging ◽  
Average Temperature ◽  
Observation Area ◽  
Evolution Behavior

In rock engineering, it is of great significance to study the failure mechanical behavior of rocks with holes. Using a combination of experiment and infrared detection, the strength, deformation, and infrared temperature evolution behavior of marble with elliptical holes under uniaxial compression were studied. The test results showed that as the vertical axis b of the ellipse increased, the peak intensity first decreased and then increased, and the minimum value appeared when the horizontal axis was equal to the vertical axis. The detection results of the infrared thermal imager showed that the maximum temperature, minimum temperature, and average temperature of the observation area in the loading stage showed a downward trend, and the range of change was between 0.02 °C and 1 °C. It was mainly due to the accumulation of energy in the loading process of the rock sample that caused the surface temperature of the specimen to decrease. In the brittle failure stage, macroscopic cracks appeared on the surface of the rock sample, which caused the energy accumulated inside to dissipate, thereby increasing the maximum temperature and average temperature of the rock sample. The average temperature increase was about 0.05 °C to about 0.19 °C. The evolution of infrared temperature was consistent with the mechanical characteristics of rock sample failure, indicating that infrared thermal imaging technology can provide effective monitoring for the study of rock mechanics. The research in this paper provides new ideas for further research on the basic characteristics of rock failure under uniaxial compression.

Sign in / Sign up

Export Citation Format

Share Document