Innovative seismic strengthening of historic masonry walls using polymer mortar and steel strips

2021 ◽  
Vol 228 ◽  
pp. 111507
Author(s):  
Xianhua Yao ◽  
Zi-Xiong Guo ◽  
Syed Humayun Basha ◽  
Qunxian Huang
Keyword(s):  
Masonry Walls ◽  
Seismic Strengthening ◽  
Historic Masonry ◽  
Steel Strips ◽  
Polymer Mortar

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.

Conservation of the Structure and Materials of Historic Masonry Walls

2014 ◽  
Vol 624 ◽  
pp. 354-362
Author(s):  
Jerzy Jasienko ◽  
Łukasz Bednarz ◽  
Dariusz Bajno
Keyword(s):  
Sedimentary Rock ◽  
Iron Ore ◽  
Retaining Wall ◽  
Raw Material ◽  
Masonry Walls ◽  
High Porosity ◽  
Historic Masonry ◽  
Iron Smelting ◽  
Additional Protection ◽  
The Status

The paper presents a structural analysis, restoration programme and scope of conservation work essential for protecting historical values based on the example of an overstretched retaining wall providing support for the embankment of an heritage church. The focus was on analysing the status of an historic stone wall constructed in part with bog iron ore (metal ore or iron-rich sedimentary rock). Ore was used for iron smelting and also as a building material. Bog iron ore was frequently used in construction across Poland, especially in places where the raw material was locally available, aesthetically attractive and had mechanical properties approximating the durability of ceramic bricks. The material was characterised by high porosity, low resistance to diffusion and high resistance to freezing, which meant that it could be used successfully in structures subjected to atmospheric impacts without additional protection

scholarly journals Numerical Modeling of Historic Masonry Structures

2016 ◽  
pp. 27-68
Author(s):  
Panagiotis G. Asteris ◽  
Vasilis Sarhosis ◽  
Amin Mohebkhah ◽  
Vagelis Plevris ◽  
L. Papaloizou ◽  
...  
Keyword(s):  
Structural Component ◽  
Applied Load ◽  
Nonlinear Behavior ◽  
Masonry Walls ◽  
Filling Material ◽  
Masonry Structures ◽  
Historic Masonry ◽  
The Individual ◽  
Masonry Units ◽  
Joint Material

The majority of historical and heritage structures around the world consist of unreinforced masonry walls. A masonry structure is composed of masonry units, such as brick or marble blocks, with or without a joint filling material, such as mortar. A masonry with a joint material is usually made of two different materials (i.e. masonry units and mortar), representing a non-homogeneous and anisotropic structural component. In other words, masonry is a discontinuous structural component whose deformations and failure mechanism are governed by its blocky behavior. Some ancient masonry structures, such as ancient columns and colonnades, are constructed without any form of joint material between the individual blocks. Therefore, the isotropic elastic continuum-based models are not suitable for the simulation of the real nonlinear behavior of masonry walls under applied load.

scholarly journals The Failure of Masonry Walls by Disaggregation and the Masonry Quality Index

Heritage ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 1162-1198
Author(s):  
Antonio Borri ◽  
Marco Corradi ◽  
Alessandro De Maria
Keyword(s):  
Quality Index ◽  
Failure Modes ◽  
Structural Response ◽  
Theoretical Models ◽  
Masonry Walls ◽  
Wall Panel ◽  
Seismic Capacity ◽  
Structural Behaviour ◽  
Historic Masonry ◽  
Type Of Failure

The visual method for assessment of the structural behaviour of historic masonry walls, known by the acronym MQI (Masonry Quality Index) was introduced in 2002 by a team of researchers from the University of Perugia, Italy. This is based on a visual survey of the faces and the cross section of a wall panel, and it aims at verifying if a wall complies with the “rules of the art”. Based on this analysis, it is possible to calculate a numerical index: numerous tests, carried out on site by the authors to validate the method, have demonstrated that the index is able to provide useful information about the mechanical characteristics and structural response, in general, of the analysed wall panel. The failure mode of a wall panel under the action of an earthquake is a critical aspect. In general, the failure modes can be categorized in two classes: masonry disaggregation and the development of a local or global mechanism of wall elements (macroelements). Several theoretical models and numerical simulations only consider the latter. In this paper, application of the MQI method is further investigated, with particular emphasis to those masonry typologies which are more prone to collapse by disaggregation during a seismic event. Under the action of an earthquake, some types of masonry are typically unable to deform and to split in macroelements, and another type of failure occurs: this is the so-called “masonry disaggregation” or “masonry crumbling”. This type of failure anticipates the ones resulting from macroelement methods or stress analysis. As a conclusion, these latter methods become completely inappropriate and potentially hazardous, as they overestimate the seismic capacity of the building under investigation. The MQI method has been adapted to assess the structural response of different types of masonry under the action of an earthquake. In detail, the aim was to verify when the phenomenon of masonry disaggregation is likely to occur.

Strengthening of Historic Masonry Structures with Composite Materials

2017 ◽  
pp. 613-647 ◽  
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.

Historical Masonry Towers: Overview, Seismic Vulnerability, Behavior During an Earthquake, Seismic Strengthening

2020 ◽  
pp. 49-66
Author(s):  
Ziad Ahmad Aldrebi
Keyword(s):  
Seismic Behavior ◽  
Seismic Vulnerability ◽  
Masonry Structures ◽  
Seismic Strengthening ◽  
Historic Masonry ◽  
Masonry Towers ◽  
Historical Masonry

The article provides an overview of historic masonry towers such as the minarets of mosques, bell towers of churches, clock towers, leaning towers, so-called "falling towers" and ruined towers. It was considered what kind of masonry, what kind of mortars the Romans, the ancient Egyptians, the Inca and Mayan cultures in America used. Some aspects of seismic vulnerability of masonry towers were studied. The modes of destruction of thin masonry structures, mechanisms of destruction of masonry in towers are considered, the seismic behavior of historical masonry towers are considered, and one of the methods of seismic strengthening using an innovative "smart" material is presented.

scholarly journals Seismic Strengthening of Unreinforced Masonry Walls using Sprayable Eco-Friendly Ductile Cementitious Composite (EDCC)

2017 ◽  
Vol 210 ◽  
pp. 154-164 ◽  
Author(s):  
Salman Soleimani-Dashtaki ◽  
Carlos E. Ventura ◽  
Nemkumar Banthia
Keyword(s):  
Unreinforced Masonry ◽  
Masonry Walls ◽  
Cementitious Composite ◽  
Seismic Strengthening
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