scholarly journals Consolidation and Strengthening of Historical Masonry by Means of Mineral Grouts: Grout Development

2015 ◽  
Vol 21 (1) ◽  
pp. 29-45 ◽  
Author(s):  
Dionys Van Gemert ◽  
Sven Ignoul ◽  
Kris Brosens ◽  
Eleni-Eva Toumbakari
Keyword(s):  
Failure Mechanisms ◽  
Brick Masonry ◽  
Historical Overview ◽  
Advantages And Disadvantages ◽  
Crack Repair ◽  
Historical Masonry

Abstract: Mass consolidation of stone and brick masonry is considered, with exclusion of pure crack repair. Damage and specific failure mechanisms in multiple leaf masonry are presented. The aims of consolidation are explained, and the inherent advantages and disadvantages of distinct strengthening and consolidation techniques are given. An historical overview of consolidation methods and of development of consolidation grout materials is given, which explains how technology evolved to the actual procedures.

Seismic Risk Mitigation of Historical Masonry Towers by Means of Prestressing Devices

2010 ◽  
Vol 133-134 ◽  
pp. 843-848 ◽  
Author(s):  
Adolfo Preciado Quiroz ◽  
Silvio T. Sperbeck ◽  
Harald Budelmann ◽  
Gianni Bartoli ◽  
Elham Bazrafshan
Keyword(s):  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Risk Mitigation ◽  
Numerical Models ◽  
Failure Mechanisms ◽  
Masonry Towers ◽  
Seismic Risk Mitigation ◽  
Historical Masonry ◽  
Observed Damage ◽  
And Behavior

This work presents the investigation of the efficiency of different prestressing devices as a rehabilitation measure for the seismic risk mitigation of historical masonry towers. As a first phase, the seismic vulnerability of theoretical masonry towers was assessed by means of numerical models validated with information from the literature, observed damage and behavior of these structures due to passed earthquakes (crack pattern and failure mechanisms), and mainly taking into account the engineering experience. Afterwards, the validated models were rehabilitated with different prestressing devices; analyzing the results and concluding which device or the combination of them improved in a better way the seismic performance of the masonry towers. Finally, the methodology will be applied in two historical masonry towers located in seismic areas; the medieval tower “Torre Grossa” of San Gimignano, Italy, and one of the bell towers of the Cathedral of Colima, Mexico.

A Contribution to the Treatment of Salt Damage in Historical Buildings

2015 ◽  
Vol 824 ◽  
pp. 127-132
Author(s):  
Iñigo Antepara ◽  
Igor Medveď ◽  
Jaromír Žumár ◽  
Robert Černý
Keyword(s):  
Building Materials ◽  
Historical Buildings ◽  
Research Teams ◽  
Porous Building Materials ◽  
Salt Damage ◽  
Advantages And Disadvantages ◽  
Historical Masonry

Salts and water may cause serious damage to historical masonries. Therefore, numerous conservation treatments have been developed by research teams for the consolidation and protection of porous building materials affected by salt attack. Here the focus is on methods for obtaining an effective desalination of historical masonry, indicating their advantages and disadvantages. It is pointed out that cellulose is a favourite material added to poultices used in desalination.

scholarly journals Experimental Investigation on the Performance of Historical Squat Masonry Walls Strengthened by UHPC and Reinforced Polymer Mortar Layers

2019 ◽  
Vol 9 (10) ◽  
pp. 2096 ◽  
Author(s):  
Bin Peng ◽  
Sandong Wei ◽  
Libo Long ◽  
Qizhen Zheng ◽  
Yueqiang Ma ◽  
...  
Keyword(s):  
High Performance Concrete ◽  
Brick Masonry ◽  
Masonry Walls ◽  
Strengthening Effect ◽  
Plane Shear ◽  
Historical Building ◽  
Reinforced Polymer ◽  
Polymer Mortar ◽  
Historical Masonry ◽  
Squat Walls

Strengthening historical brick masonry walls is important because these walls are major load-bearing members in many architectural heritages. However, historical brick masonry has low elastic modulus and low strength, historical masonry walls are prone to surface treatment or other structural intervention, and some of the walls lack integrity. These characteristics make effective strengthening of historical masonry walls difficult. To address the issue, strengthening layers made up of ultra-high performance concrete (UHPC) are potentially useful. To investigate the strengthening effect of the UHPC layers, the authors constructed three squat walls using historical bricks and mortar collected from the rehabilitation site of a historical building, and strengthened two of the walls with a UHPC layer and a reinforced polymer mortar layer respectively. The three walls were broken down by horizontal cyclic force along with constant vertical compression, and then the unstrengthened one was strengthened in-situ by a UHPC layer and was tested again. The experimental results indicate that the UHPC layers significantly improved the in-plane shear resistance and cracking load of the squat walls, without decreasing the walls’ ultimate deformation. They effectively strengthened both moderately and severely damaged historical masonry walls, because the UHPC filled the existing damages and improved the integrity of the masonry substrate. In addition, the UHPC layers intervened the historical walls less than the reinforced polymer mortar layer. Therefore, the UHPC layers are efficient in strengthening historical squat masonry walls.

Social Media, the Internet, and Trial by Jury

2018 ◽  
Vol 14 (1) ◽  
pp. 259-270 ◽  
Author(s):  
Thaddeus Hoffmeister ◽  
Ann Charles Watts
Keyword(s):  
Social Media ◽  
Digital Technology ◽  
The Internet ◽  
Historical Overview ◽  
Advantages And Disadvantages ◽  
Media And Communication

This review starts with a historical overview of trial by jury and then moves to a discussion of media and communication. This is followed by an examination of the advantages and disadvantages associated with jurors and digital technology. The heart of the article is a review of six scholarly studies that attempt to explain why jurors use the Internet, as well as methods for combating such use. The article concludes with recommendations for future areas of research.

scholarly journals Analysis on Factors Affecting the Self-Repair Capability of SMA Wire Concrete Beam

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Li Sun ◽  
Dezhi Liang ◽  
Qianqian Gao ◽  
Jianhong Zhou
Keyword(s):  
Concrete Beam ◽  
Cement Mortar ◽  
Resin Cement ◽  
The Self ◽  
Factors Affecting ◽  
Advantages And Disadvantages ◽  
Crack Repair ◽  
Self Repair ◽  
Unbonded Length ◽  
Silicone Polymer

Crack expansion of concrete is the initial damage stage of structures, which may cause greater damage to structures subject to long-term loads or under extreme conditions. In recent years, the application of intelligent materials to crack self-repair has become a hotspot among researchers. In order to study the influence of factors on the self-repair capability of shape memory alloy (SMA) wire concrete beam, both theoretical and experimental methods were employed for analysis. For the convenience of experiment, composite materials (epoxy cement mortar and silicone polymer clay) instead of concrete were used. The SMA wires were externally installed on and internally embedded in epoxy resin cement mortar beams and silicone polymer clay beams. Comparison of crack repair situation between two installation methods turns out that both methods possess their own advantages and disadvantages and should be employed according to the actual situation. The influence of unbonded length on the self-repair capability of embedded type SMA wire beams and the necessary minimum unbonded length to achieve self-repair function were studied. The results state clearly that the longer the unbonded length is, the better the crack repair situation is.

Investigation of Failure Mechanisms in Ti Containing Brazing Alloys Used in SOFC/SOEC Environments

2010 ◽  
Author(s):  
Wolff-Ragnar Kiebach ◽  
Ruth Knibbe ◽  
Kristian B. Frederiksen ◽  
Ming Chen ◽  
Lars Mikkelsen ◽  
...  
Keyword(s):  
Ferritic Steel ◽  
Failure Mechanisms ◽  
Annealing Process ◽  
Yttria Stabilized Zirconia ◽  
Reaction Products ◽  
Stabilized Zirconia ◽  
Advantages And Disadvantages ◽  
Active Metal ◽  
Reported Data

The two braze alloys TiCuNi® and Silver-ABA® were tested as possible candidates for seals in SOFC or SOEC stacks. The different Ti amount in the samples allowed an evaluation of Ti as a matrix filler and as an active metal/wetting agent in brazing alloys. The sealing ability towards ferritic steel and yttria-stabilized-zirconia (YSZ) was investigated. After the sealing process steel/braze/YSZ joints were further annealed in oxidizing (Air) or reducing (9% H2 in Ar) atmospheres at 750 °C for 150 h. The boundaries of the braze and the joining partners for as-sealed and annealed samples were examined with SEM/EDS. XRD and EXAFS were used to characterize reaction products after the annealing process. Based on these results and taking before reported data into consideration, the advantages and disadvantages of Ti containing seals and the role of Ti in failure mechanism are discussed. Even if the use of Ti in active brazing alloys has its benefits, the disadvantages caused by Ti and its reaction products strongly suggest the use of Ti free brazes in SOFC/SOEC applications.

scholarly journals Historical overview of the selection indices applied in pig breeding

2019 ◽  
Vol 23 (1) ◽  
Author(s):  
Oleksandr Kodak ◽  
Nagy István
Keyword(s):  
Selection Index ◽  
Historical Overview ◽  
Economic Aspects ◽  
Breeding Methods ◽  
Breeding Values ◽  
Advantages And Disadvantages ◽  
Selection Indices

Authors summarized the different breeding methods used in the pig breeding sector during the last few decades. Advantages and disadvantages of the conventional selection index procedures were summarized. The superiority of BLUP breeding values over the simple phenotypic measurements are clarified. The economic aspects of the different traits are also examined and the currently most up to date economic BLUP indices were also introduced.

Early Sport Specialization: A Historical Perspective

2015 ◽  
Vol 4 (3) ◽  
pp. 220-229 ◽  
Author(s):  
Maureen M. Smith
Keyword(s):  
Historical Perspective ◽  
Team Sports ◽  
The United States ◽  
Physiological Effects ◽  
Historical Overview ◽  
Common Occurrence ◽  
Young Athletes ◽  
Advantages And Disadvantages ◽  
Individual Sports ◽  
Online Sources

This article provides a historical overview of the practice of early sport specialization, primarily in the United States. Sport specialization as practiced by young athletes has been a common occurrence in several individual sports for more than 60 years. More recently, focusing on one sport has gained traction as common practice for young athletes involved in team sports. Sport specialization as a topic of research inquiry has been examined by various disciplines in kinesiology to determine the efficacy of the practice, the physiological effects, and the advantages and disadvantages, as well as to offer possible solutions to the drawbacks associated with sport specialization. Popular press outlets, including newspapers, books, magazines, and online sources, have also joined the debate over the merits of sport specialization.

scholarly journals TREATMENT OF HYPERBILIRUBINEMIA: VARIOUS TECHNOLOGIES AND CHALLENGES

2018 ◽  
Vol 80 (5) ◽  
Author(s):  
Esmaeil Salimi ◽  
Azadeh Ghaee ◽  
Ahmad Fauzi Ismail ◽  
Mohd Hafiz Dzarfan Othman
Keyword(s):  
Side Effects ◽  
Affinity Chromatography ◽  
Plasma Exchange ◽  
Historical Overview ◽  
Separation Techniques ◽  
Advantages And Disadvantages ◽  
Interventional Therapies

Bilirubin removal from blood and curing patients suffering from hyperbilirubinemia by surgery, medication or interventional therapies was common, previously. Alternative bilirubin separation techniques such as plasma exchange, affinity chromatography and etc., are efficient in reducing high levels of bilirubin with fewer side effects. However, due to the various causes and complications associated with hyperbilirubinemia, different strategies are needed for the treatment. This article offers a historical overview on these strategies, challenges and also outlines the technological advantages and disadvantages associated with various bilirubin removal techniques.

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