Multi-Leaf Stone Masonry Walls in Egypt: A Legend

Multi-leaf stone masonry walls are a typical construction technique in architectural heritage in Egypt. The assessment, modeling, and strengthening of historic masonry walls of multi-leaf systems essentially require suitable knowledge of their construction technology, typology, geometrical characteristics, and the properties of their components. Within the current research project, a comprehensive structural survey of multiple-leaf walls of medieval historic buildings in Cairo was performed. The observation and statistical analyses allowed characterization of the transversal section of the surveyed walls, as well as examination and identification of the construction materials and techniques. The slenderness ratios of this type of wall, its blocks’ dimensions, the utilized connectivity between the inner and outer leaves, and leaves ratio were also investigated. Three construction hypotheses of multiple-leaf stone masonry walls are presented considering weak, thick, and monolithic core infill layers. The study’s objectives were to enlarge the knowledge of typology, morphology, and construction materials used in three-leaf masonry walls and provide a proper characterization as a prerequisite for determining the most suitable materials and techniques for further strengthening interventions.

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Experimental Investigations and Microstructural Characterization of Construction Materials of Historic Multi-Leaf Stone-Masonry Walls

Heritage ◽

10.3390/heritage4030135 ◽

2021 ◽

Vol 4 (3) ◽

pp. 2390-2415

Author(s):

Osama Amer ◽

Danila Aita ◽

Ezzeldin K. Mohamed ◽

Akram Torky ◽

Ashraf Shawky

Keyword(s):

Building Materials ◽

Inner Core ◽

Construction Materials ◽

Core Layer ◽

Mineralogical Composition ◽

Stone Masonry ◽

Thermal Resistivity ◽

Experimental Investigations ◽

Masonry Walls

In order to correctly define the pathology of multiple-leaf stonemasonry walls and determine the appropriate interventions for its conservation and preservation, comprehensive studies on its building materials should be carried out since the overall behaviour of masonry structures is highly dependent on the characterization of its construction materials. Consequently, an interdisciplinary procedure for construction material characterization used in multiple-leaf stone-masonry walls in Egypt has been implemented to enrich documentation, conservation and restoration issues of this type of wall. The research methodology integrates experimental data obtained through on-site sampling, conducted tests and analyses, historical information, and field survey observations. The fundamental physical and mechanical properties of the masonry elements were examined by incorporating stone blocks, mortars and core-infill materials. The mineralogical composition and interlocking textures of the collected samples were investigated utilizing a large range of complementary investigation and analysis techniques, including polarizing microscopy, X-ray diffraction (XRD), thermal analysis (TG/DTA), and environmental scanning electron microscope (ESEM) attached to an EDX unit. Through the results thus obtained, a complete characterization of the mineralogical composition; physical–mechanical, chemical, and thermal properties; and the interlocking textures of the construction materials of both the outer and inner-core layers was performed. The outer leaves of the majority of the multiple-leaf stone-masonry walls in medieval architectural heritage were mainly built of well-dressed limestone blocks with nearly uniform dimensions, while the inner-core layer was usually built of stone-rubble infill with bending lime-based mortar. The uniaxial compressive strengths of core infill (corresponding to the inner core layer) and lime-based mortar of the embedded joints are shown to be 85 and 92.5% lower than the limestone units of the outer layer, respectively. Moreover, experimental observations indicate that the inner core layer exhibits the highest porosity values; consequently, deteriorated, loose and cohesionless core infill could greatly affect the durability and thermal resistivity of this kind of wall. The results provide scientific support for investigating the overall structural behaviour of this type of walls and for decision-making in future conservation and restoration strategies.

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Experimental Evaluation of Shear Behavior of Stone Masonry Wall

Materials ◽

10.3390/ma14092313 ◽

2021 ◽

Vol 14 (9) ◽

pp. 2313

Author(s):

Maria Luisa Beconcini ◽

Pietro Croce ◽

Paolo Formichi ◽

Filippo Landi ◽

Benedetta Puccini

Keyword(s):

Shear Behavior ◽

Stone Masonry ◽

Masonry Walls ◽

Mechanical Parameters ◽

In Situ Tests ◽

Capacity Curves ◽

Historical Structures ◽

Definition Of

The evaluation of the shear behavior of masonry walls is a first fundamental step for the assessment of existing masonry structures in seismic zones. However, due to the complexity of modelling experimental behavior and the wide variety of masonry types characterizing historical structures, the definition of masonry’s mechanical behavior is still a critical issue. Since the possibility to perform in situ tests is very limited and often conflicting with the needs of preservation, the characterization of shear masonry behavior is generally based on reference values of mechanical properties provided in modern structural codes for recurrent masonry categories. In the paper, a combined test procedure for the experimental characterization of masonry mechanical parameters and the assessment of the shear behavior of masonry walls is presented together with the experimental results obtained on three stone masonry walls. The procedure consists of a combination of three different in situ tests to be performed on the investigated wall. First, a single flat jack test is executed to derive the normal compressive stress acting on the wall. Then a double flat jack test is carried out to estimate the elastic modulus. Finally, the proposed shear test is performed to derive the capacity curve and to estimate the shear modulus and the shear strength. The first results obtained in the experimental campaign carried out by the authors confirm the capability of the proposed methodology to assess the masonry mechanical parameters, reducing the uncertainty affecting the definition of capacity curves of walls and consequently the evaluation of seismic vulnerability of the investigated buildings.

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Effects of Infills in the Seismic Performance of an RC Factory Building in Pakistan

Buildings ◽

10.3390/buildings11070276 ◽

2021 ◽

Vol 11 (7) ◽

pp. 276

Author(s):

Nisar Ali Khan ◽

Giorgio Monti ◽

Camillo Nuti ◽

Marco Vailati

Keyword(s):

Numerical Model ◽

Construction Materials ◽

Building Codes ◽

Construction Technique ◽

Infill Walls ◽

Mortar Strength ◽

Materials Used ◽

Seismic Response Of Buildings

Infilled reinforced concrete (IRC) frames are a very common construction typology, not only in developing countries such as Pakistan but also in southern Europe and Western countries, due to their ease of construction and less technical skills required for the construction. Their performance during past earthquakes has been in some cases satisfactory and in other cases inadequate. Significant effort has been made among researchers to improve such performance, but few have highlighted the influence of construction materials used in the infill walls. In some building codes, infills are still considered as non-structural elements, both in the design of new buildings and, sometimes, in the assessment of existing buildings. This is mainly due to some difficulties in modeling their mechanical behavior and also the large variety of typologies, which are difficult to categorize. Some building codes, for example, Eurocode, already address the influence of infill walls in design, but there is still a lack of homogeneity among different codes. For example, the Pakistan building code (PBC) does not address infills, despite being a common construction technique in the country. Past earthquake survey records show that construction materials and infill types significantly affect the seismic response of buildings, thus highlighting the importance of investigating such parameters. This is the object of this work, where a numerical model for infill walls is introduced, which aims at predicting their failure mode, as a function of some essential parameters, such as the friction coefficient between mortar and brick surface and mortar strength, usually disregarded in previous models. A comprehensive case study is presented of a three-story IRC frame located in the city of Mirpur, Pakistan, hit by an earthquake of magnitude 5.9 on 24 September 2019. The results obtained from the numerical model show good agreement with the damage patterns observed in situ, thus highlighting the importance of correctly modeling the infill walls when seismically designing or assessing Pakistani buildings that make use of this technology.

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Revaluation of Ksar El-Haouita in Laghouat, Algeria

10.52460/issc.2021.001 ◽

2021 ◽

Author(s):

Fatiha Imane Mahcar ◽

Belkacem Takhi

Keyword(s):

Morphological Analysis ◽

Construction Materials ◽

Architectural Heritage ◽

Theoretical Underpinning ◽

Great Resistance ◽

Basic Principles ◽

Construction Techniques ◽

Materials Used ◽

Local Materials

Algeria has a rich urban and architectural heritage, which presents regional specificities. Once the ksour was a symbol of balance and perfect harmony with its environment, unfortunately today they no longer reflect their former function. The Ksourian architecture, including that of Laghouat is a prestigious heritage of high value; it is the testimony of genius knowledge and the capacity of their occupants to adapt to the difficult environment. The housing is considered the essential core of this architecture it represents the entire composition of the ksar, its design is inspired by the immediate environment and respects ancestral social values. It is characterized by a simple architecture and simple construction techniques which are based on the construction in load-bearing walls, the construction materials used are local materials of great resistance and less expensive. This study addresses the theme revaluation of heritage, particularly our case study ksar El-Haouita which has experienced a neglecting and depopulation due to several factors. The ksar El-Haouita is among the most famous ksour located in the south of Algeria and exactly in the region of Laghouat. It is built with simple materials and techniques of construction. The construction materials used are local materials like stones and lime found in the environmental surroundings of the ksar. The aim of this study is to identify the major causes of the degradation of ksar, also to preserve ksar El-Haouita through specific operations and to improve the tourist attractiveness of ksar El-Haouita in order to promote heritage, to convert it back into sustainable Saharan tourism. Our study based in the first place; on a theoretical underpinning which contains the notions that have a relation with our theme, the problematic and the envisaged objective, then a presentation of ksar followed by a morphological analysis accompanied by identification of the problems to identify the phenomena of damage and its disfigurement. The last step is to treat an aspect for the development of ksar, this aspect is devoted to the restitution of the defensive system (doors, ramparts, ramparts of houses and towers) of the ksar, through a diagnostic and several operations like (rehabilitation and reconstruction). The aim result of this study is to show that the revaluation of the ksar is a very vast operation and proposes interventions that allow the preservation of the ksar and also to understand the elements that help the success of interventions and to put some of the parameters considered as reference elements and basic principles for the operations on the ksar and among these operations it is (the case study, which is the restitution of the defensive system of ksar El-Haouita).

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The Conservation of Earthen Architectural Heritage in Seismic Areas

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.133-134.65 ◽

2010 ◽

Vol 133-134 ◽

pp. 65-77

Author(s):

Julio Vargas Neumann

Keyword(s):

Seismic Vulnerability ◽

Construction Materials ◽

Stone Masonry ◽

Conservation Strategies ◽

Architectural Heritage ◽

The Past ◽

Earthen Structures ◽

Historical Monuments ◽

Conservation Principles ◽

Seismic Forces

The acceleration of climate change and the increasing frequency of natural disasters mean that there is an urgent need to adapt conservation strategies for architectural heritage to the world’s new demands and situations. This is particularly relevant for the most vulnerable constructions, such as earthen structures. Because of the dramatic effect that earthquakes can have on architecture, and especially on historical monuments, they have been studied for the past 50 years. Earthquakes divide the world in two very distinct geographic areas: seismic and non-seismic. The seismic vulnerability of earthen architectural heritage, such as earthen structures and mud mortar masonry, evidences in by how weak they are when compared to structures built using other construction materials (10 to 15 times weaker). Humanity’s past experience in the conservation of architectural heritage allows us to be aware of the need to improve and eventually perfect the existing conservation charters, which were discussed and signed in Europe in the last century. These charters do not make a distinction between heritage conservation in seismic and non-seismic areas. It is imperative to address this particular issue, as seismic forces can be too strong for earthen constructions to resist, which can lead to their irreparable collapse. Inspired by the Venice Charter and China´s principles as well as by more modern documents, such as the Burra, Mexico, Zimbabwe, Lausana Charters, researchers have tried to establish adequate and resistant conservation guidelines, based on achieving the best structural performance using a minimum permanent and reversible reinforcement. Although this involves causing some impact on the architectural heritage, it also means that human lives and buildings can be protected. The paper will provide real examples to illustrate these cases and will attempt to outline the conservation principles required to protect vulnerable structures, such as those earthen constructions or mud mortar brick or stone masonry built in seismic areas.

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Mechanical characterization of rubble stone masonry walls using non and minor destructive tests

Construction and Building Materials ◽

10.1016/j.conbuildmat.2013.02.007 ◽

2013 ◽

Vol 43 ◽

pp. 266-277 ◽

Cited By ~ 31

Author(s):

I. Lombillo ◽

C. Thomas ◽

L. Villegas ◽

J.P. Fernández-Álvarez ◽

J. Norambuena-Contreras

Keyword(s):

Mechanical Characterization ◽

Stone Masonry ◽

Masonry Walls ◽

Rubble Stone Masonry

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Validation of non-destructive characterization of the structure and seismic damage propagation of plaster and texture in multi-leaf stone masonry walls of cultural-artistic value

Journal of Cultural Heritage ◽

10.1016/j.culher.2013.11.004 ◽

2014 ◽

Vol 15 (5) ◽

pp. 490-498 ◽

Cited By ~ 9

Author(s):

Patricia Cotič ◽

Zvonko Jagličić ◽

Vlatko Bosiljkov

Keyword(s):

Seismic Damage ◽

Stone Masonry ◽

Masonry Walls ◽

Damage Propagation ◽

Artistic Value ◽

Non Destructive ◽

Non Destructive Characterization

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Characterization of Classical Construction Materials used in Ethiopian Architecture for the Restoration of their Historic and Artistic Heritage

International Journal of Architectural Heritage ◽

10.1080/15583058.2018.1489014 ◽

2018 ◽

Vol 13 (6) ◽

pp. 855-869

Author(s):

Jorge Alberto Durán-Suárez ◽

Mª Paz Sáez-Pérez

Keyword(s):

Construction Materials ◽

Materials Used ◽

Artistic Heritage ◽

Classical Construction

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Strengthening of Historic Masonry Structures with Composite Materials

Materials Science and Engineering ◽

10.4018/978-1-5225-1798-6.ch025 ◽

2017 ◽

pp. 613-647 ◽

Cited By ~ 1

Author(s):

Marco Corradi ◽

Adelaja Israel Osofero ◽

Antonio Borri ◽

Giulio Castori

Keyword(s):

Composite Materials ◽

Stone Masonry ◽

Masonry Walls ◽

Masonry Building ◽

Masonry Buildings ◽

Historic Masonry ◽

Reinforced Masonry ◽

Total Lack ◽

Recent Earthquakes ◽

Masonry Vaults

Existing un-reinforced masonry buildings made of vaults, columns and brick and multi-leaf stone masonry walls, many of which have historical and cultural importance, constitute a significant portion of construction heritage in Europe and rest of the world. Recent earthquakes in southern Europe have shown the vulnerability of un-reinforced masonry constructions due to masonry almost total lack of tensile resistance. Composite materials offer promising retrofitting possibilities for masonry buildings and present several well-known advantages over existing conventional techniques. The aim of this work is to analyze the effectiveness of seismic-upgrading methods both on un-damaged (preventive reinforcement) and damaged (repair) masonry building. After a brief description of mechanical and physical properties of composite materials, three different applications have been addressed: in-plane reinforcement of masonry walls, extrados and intrados reinforcement of masonry vaults/arches and masonry column confinement with composite materials.

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