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Steel I-beam, brick jack arch slabs have long been used to floor and roof industrial and residential buildings in many parts of the world. Collapse of a large number of these non-homogeneous one-way slabs during past earthquakes has highlighted their poor seismic performance. However, due to their easy construction together with low cost, the jack-...
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... the floors at a later date. For the pur- pose of our comparative investigations, the first and third floors of the building were covered using the two-way steel grid system and the second and fourth floors of the building were covered using the one-way system. Dimensions and details of a 5.0 by 6.0 m floor panel, used for experiments is given in Fig. 5. Non-destructive dynamic tests were carried out on the second and third floors of the building. These two floors have identical details and boundary conditions, except that in the first floor two, equally spaced, transverse beams were used to create a two-way jack-arch system. Dynamic impulse tests were carried out on the floors to ...
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Citations
... The disjointed steel transversal beams will subsequently be an element of a steel grid that enables the distribution of applied loads in two-way directions. The brick slab system, which was developed and constructed, was found to improve the diaphragm's action and resistance to gravity and seismic stresses [2]. A research investigation was conducted on how the existing structures performed during the 2003 Bam earthquake. ...
In this study, five one-way brick slab specimens were manufactured to investigate the behavior of brick slabs composed of various types of bricks (solid bricks, perforated bricks, and cellular concrete blocks (thermostone). The span ranges from 600 to 800 mm, while the camber ranges from 0 to 30 mm. Previously, cellular concrete blocks, solid and perforated clay bricks were employed as the building materials. These samples were tested by being subjected to flexural three-point loading. The results revealed that increasing camber by 30 mm for solid brick specimens increased ductility, and ultimate strength, by 5.5% and 77.62, respectively. Increasing the span from 600 to 800 mm for solid brick specimens decreased the ultimate strength and ductility by 37.96% and 6.83%, respectively. Cellular concrete blocks can be used in the construction of slabs due to their lightweight and acceptable structural response when compared to solid brick specimens. Due to their good structural performance and lightweight, perforated bricks can be used to build brick slabs. Brittleness and the sudden collapse of the brickwork arch characterized the failure mode in all samples.
... In more recent years, RC beams have been introduced using the same technology (Diodato et al., 2015;Garcia-Castillo et al., 2021). The jack arch originated in Europe, expanded to the Americas, and by the mid-twentieth century was used in East Europe, the Middle East (Maheri et al., 2012;Khan et al., 2013) as seen in Iran (Eslami et al., 2012;Zahrai, 2015;Shabdin et al., 2020), Iraq (Kharrufa, 2007), Turkey (Ozdemir et al., 2017), and Sudan (Mukhtar, 1980;Adam and Agib, 2002), Nepal (Motra et al., 2021), and the Indian subcontinent (Maheri and Rahmani, 2003;Maheri et al., 2012;Khan et al., 2013). It provided span flexibility, upper levels, structural safety, ease of building due to labor and material availability, and good thermal performance (Maheri and Rahmani, 2003;Khan et al., 2013;Leo Samuel et al., 2017). ...
... The jack arch originated in Europe, expanded to the Americas, and by the mid-twentieth century was used in East Europe, the Middle East (Maheri et al., 2012;Khan et al., 2013) as seen in Iran (Eslami et al., 2012;Zahrai, 2015;Shabdin et al., 2020), Iraq (Kharrufa, 2007), Turkey (Ozdemir et al., 2017), and Sudan (Mukhtar, 1980;Adam and Agib, 2002), Nepal (Motra et al., 2021), and the Indian subcontinent (Maheri and Rahmani, 2003;Maheri et al., 2012;Khan et al., 2013). It provided span flexibility, upper levels, structural safety, ease of building due to labor and material availability, and good thermal performance (Maheri and Rahmani, 2003;Khan et al., 2013;Leo Samuel et al., 2017). Steel I-beams were one reason the jack arch became socially unpopular and associated with poverty, according to Kharrufa (2007). ...
As a response to rising housing prices and the high cost of materials in the building and construction industry, a rural prototype house (the Ecofordable House) was built with alternative technologies. The house is located in the western desert zone of Giza, Egypt, and features enhanced vernacular technologies with local materials. Interlocking compressed stabilized earth brick walls, partially reinforced, jack arch and funicular shell roofs, and date palm midribs were employed in an attempt to reduce the usage of steel, fired bricks, cement, and imported wood. The present research evaluates the house’s construction cost-effectiveness and affordability through detailed real-world data and comparisons of material quantities, labor, and costs with those of conventional methods. The “price-to-income ratio” is used as an indicator of affordability. According to the findings, walls cut costs by half, roofs by a quarter, and midribs by two-thirds; the alternatives combined saved 45%, and the house saved a quarter of the cost after adding common expenses. Moreover, less than one-third of steel, fired bricks, and cement were utilized. In the Egyptian context of government-built houses, the prototype would be affordable for most Egyptian income brackets while the conventional house was expensive for the lowest three. The findings provide empirical support for the economic advantages of enhanced vernacular technologies as alternatives and address residential affordability in similar contexts.
... The center is the span between two steel I-sections or between two timber joists. Due to the rapid setting of gypsum mortar, it is used to bind clay brick units together when building the spans between steel I-section beams (Maheri & Rahmani, 2003). ...
... Fig. 1 Types of jack arch slabs using steel beam and timber joist. a Construction details of a traditional, one-way jack arch slab (Maheri et al., 2003). b Cross section of a historic timber flooring system-dimensions in cm (Garcia-Castillo et al., 2021) 1 3 ...
The use of fiber-reinforced polymer rope (FRPR) increases the seismic performance of unreinforced clay brick masonry slabs and the flexural strength of jack arch slabs or roofs. This study represents an attempt to explore the capability of using FRPR for strengthening the jack arch slabs. For this purpose, ten jack arch slab specimens were built and tested under three-point load conditions. The main parameters investigated were the brick type (solid and perforated), camber (0 and 30 mm), span width (700, 730, and 950 mm), strengthening scheme on the behavior of the jack arch slab of FRPR, and number of FRPR points (i.e., number of FRPR strengthening points used for each span). The results show that using perforated brick types enhanced the ultimate carrying capacity of the slabs compared with the solid type. With increasing camber, it was observed that the ultimate capacity of the slabs also increased by the range of 13–11% for the solid and perforated specimens, respectively. Furthermore, increasing the span width resulted in a 69% reduction in maximum deflection. FRPR can be utilized for strengthening masonry buildings and historical structures.
... As a consequence, the unconnected parallel steel beams will be joined to form an interconnected steel grid, allowing vertical loads to be transmitted in both directions. It was found that the developed method increased diaphragm action and resistance to gravity and seismic stresses [2]. The combined effect of the ferrocement layer and the jack arch slab enhanced flexural strength, stiffness, and ductility without considerably increasing the slab's weight [3]. ...
This paper describes a new method for making jack arch slabs out of precast ferrocement panels that have been composited with various clay bricks (solid and perforated bricks), cellular concrete block units, and gypsum mortar. The slab system was composed of two layers that were linked together by gypsum mortar. The first layer was a ferrocement precast panel that worked as a formwork, and the second layer was composed of brick units and gypsum mortar. Experimentally, the structural behavior of a ferrocement-brick composite slab subjected to a three-point flexural load was investigated in this study. During the study, seventeen specimens were used, eleven of which were one-way composite slab specimens that were fabricated and tested to demonstrate the effects of span length, camber height, volume fraction, and brick types on the structural behavior of the ferrocement-brick composite jack arch slab, five of which were precast ferrocement layers to evaluate their capacity to carry construction loads, and the final specimen was a one-way jack arch slab as a reference specimen. The results in terms of ultimate loads, ductility index, and failure mode revealed that all-composite ferrocement slabs with solid and perforated bricks, as well as cellular concrete block specimens, have (19.53-354.24%) and (47.88-241.14%) higher ultimate strength and ductility index than the reference specimen, respectively. The response of the composite slab to flexural loads was acceptable, and it may be used in jack-arch slab applications. Precast panel specimens have a greater ductility index than the reference specimen by a range of 22.73-105.70%, and were capable of securely bearing construction loads without the use of mid-supports or forms. The composite specimen elements' failure mode revealed ductile and composite behavior, changing a pure brittle material (clay brick and cellular concrete blocks) into a ductile composite material due to the use of a ferrocement precast layer.
... This system allows transmission of the vertical load in two directions. The proposed technique found that diaphragm action and resistance to gravity and seismic loads were improved (Maheri & Rahmani, 2003). Experimentally investigated the effect of using a concrete overlay layer on top of the jack arch slab. ...
Abstract
The aim of this study is to propose a new, sustainable, and efective method for the construction of jack-arch slabs. The main
idea of this method is to produce lightweight precast ferrocement elements in the form of sandwich panels to be used in the
jack-arch slab between the steel I-section beam. In this study, eight specimens were manufactured and tested under three�point loads. The specimens are made of two ferrocement layers of 15 mm in thickness, separated by core material prisms
(200×100×100) mm. Two diferent core materials are used; these are styropor or cellular concrete block (thermostone).
The precast ferrocement sandwich slab has a section depth of 130 mm (15 mm for each ferrocement layer and 100 mm for
the prisms). One of the specimens is made of clay brick and gypsum mortar to represent a traditional jack-arch slab and is
employed as a control. The remaining seven specimens are ferrocement sandwich composite slabs. The ferrocement laminates
consist of four layers of steel wire mesh embedded in a high-fowable cement mortar of 68 MPa compressive strength. The
main variables considered in the study were the type of core material (styropor or cellular concrete), span length, section
depth of the slab, and shear connectors. The results regarding the ultimate loads and ductility showed that all precast ferrocement sandwich slab specimens had a higher than the control by (471.23–1216.89%) and (60.55–205.50%), respectively.
Using steel wire of 3 mm diameter as shear connectors improved the ultimate loads and ductility by (863.01–1216.89%) and
(96.33–205.50%), respectively, over the control specimen. The ultimate load and ductility index are improved by 77.48 and
14.28% when section depth is increased from 130 to 160 mm, respectively. Ferrocement sandwich composite slab specimens
have higher fexural strength and modulus than the control specimen by a range of (579.16–1231.25%) and (65.05–247.91%),
respectively. The reduction in weight of the sandwich slabs compared to the traditional jack arch reached 43.13% for the
styropor core material. The modes of failure showed that the ferrocement sandwich slabs have a ductile behavior. Accord�ing to the encouraging results of the study, the proposed ferrocement sandwich slab can be used as an alternative to the
traditional brick-work slab.
... These one-way floor slabs, called jack arch floors, are very common in many historical and existing buildings of the Mediterranean countries, and especially in the eastern coast of Spain [13,14]. Only a few studies, focusing on Iranian masonry or steel buildings, have contributed to the evaluation of the shear stiffness and the seismic behaviour of this type of floor slabs [15][16][17][18][19]. ...
... Later, this floor slab technique was adopted in Eastern Europe as well as in the Middle East and the Indian subcontinent. Some of the advantages of this floor system, namely easy construction, technical simplicity and low-cost, made it a popular choice for industrial buildings and URM urban buildings in many countries, as well as for high-rise steel and concrete framed buildings [16]. ...
The type of floor system has a decisive role in the seismic performance of unreinforced masonry buildings. The in-plane stiffness of the floors has to be adequately represented in the numerical modelling of existing buildings, as it can influence their seismic capacity. This paper investigates the seismic behaviour of one-way arch floor systems composed of steel or timber beams, and ceramic tile vaults. The main objective of the research is to provide a numerical procedure for the simplified modelling of jack arch floor systems in the seismic assessment of unreinforced masonry buildings. The presented approach aims to provide values for the orthotropic properties of simplified floor models composed of elastic 2D shell elements. The orthotropic elastic properties are computed and calibrated by means of comparisons with detailed 3D nonlinear models of the floors. The case study is a multi-storey existing masonry building of the historical “Eixample” district in Barcelona, which includes one-way arch floor systems. The Finite Element Method has been used for the numerical simulation of the seismic performance through nonlinear static (pushover) analyses. The results of the study contribute to a better understanding of the effect of the behaviour of one-way floors with steel or timber beams and tile vaults on the seismic response of masonry buildings. This work provides indicative values for the proper modelling of these particular floor slabs. The proposed methodology is also applicable to the numerical simulation of any other one-way floor system.
... Considering the repeated observation of this beneficial secondary role of the confining system in different earthquakes, it is suggested that some modifications be made in the next revisions of the masonry building codes to also detail the horizontal and vertical tie elements as a temporary gravity load-resisting frame to act after partial collapse of the masonry walls. • Sufficient support length of the steel beams of the jack arch slabs (Maheri and Rahmani 2003;Maheri et al. 2012) on the walls (see Fig. 7) or the adequate connection of the slab beams to their supports such as the tie-beams, prevented collapse of the roofs, even after the out-of-plane movement of the walls or sliding of the roofs on their supports. ...
Confined masonry buildings are common structural systems in many seismic-prone regions of the world. According to the building code provisions, an appropriate continuous tie system should be provided in these buildings to bind the structural elements together and stop separation and disintegration of these elements under ground shaking. Since usually prescriptive design provisions with minimum calculations are used for constructing confined masonry buildings, investigating their performance in real seismic events is of great importance. In this paper observations made on the performance of confined masonry buildings during the destructive Sarpole Zahab, Iran, earthquake of November 12, 2017 are reported. The earthquake had caused different types of damage in both the structural and non-structural elements of the buildings. Damages were found to be primarily due to large structural irregularities and poor workmanship. Nonetheless, it was noted that those buildings with no significant irregularities, in the construction of which all the code’s main provisions had been followed, survived the earthquake and did not experience partial or total collapse. It is suggested that in the taller, two or three storey buildings, with the aim of enhancing the lateral deformation capacity of the load bearing walls, some modifications on the dimensions and reinforcement detailing of the vertical tie elements, particularly those located at the corners of the buildings, to be carried out. In addition, as it has been repeatedly observed in the past earthquakes that after the partial or total collapse of the load bearing walls the tie-beams and tie-columns have served as a secondary gravity load-resisting system and prevented collapse of floor and roof slabs, it is suggested that the adequacy of the current prescriptive detailing of the tie system in acting as a temporary secondary load-bearing system to be verified.
... Despite these advantages and the widespread application of this flooring system in old buildings, no specific design codes can be found to address its engineering design procedure. is made the jack arch floors be constructed empirically based on previous practices [26]. e jack arch floors typically satisfy the strength requirements in resisting the gravity loads. ...
A common situation found in many old and modern buildings is the annoying floor vibration. Many old buildings suffer floor vibration as no specific design guidelines were employed to limit the situation. In modern buildings, the development of floors of lighter weight, longer span, and less inherent damping is the main cause for the annoying vibration. In this paper, as a novel application, the influence of viscoelastic tuned mass dampers (TMDs) in vibration mitigation of an existing steel joist jack arch floor structure is investigated using finite element (FE) analysis. Results of a free vibration test conducted on the prototype TMDs are used to validate the FE model. The jack arch floor is subjected to the walking loads of different stepping rates of 1.5, 2, and 3 Hz. Various load models that are available in the literature are used to define the dynamic walking load, and the response mitigation is carried out based on the most critical load models. The influence of design parameters such as the excitation frequency, configuration of the individual dampers in the TMD system, and the mass ratio of the TMD system on the vibration mitigation of the floor structure are investigated in detail. Results of this study indicate that the viscoelastic TMDs are effective in vibration mitigation of jack arch floor structures.
... The first slim floor system appeared in England during the last decade of the nineteenth century, as the Jack arch floor system [1], made of double-T section steel beams with flat masonry arches in-between. Although this flooring system was very popular [2], improvement has been made by replacing the masonry with the concrete material, which provides better behavior under horizontal dynamic loads [3]. ...
Featured Application: The simplified method can be used by practitioner engineers as a tool for computing the fire resistance of slim floor beams with double-T steel section. Abstract: The slim floor beams, characterized by the steel profile embedded in the concrete slab, may be found in different configurations, based on the shape of the steel profile cross-section, which can vary from a rectangular to double-T section. While the most common shape used nowadays is the double-T cross-section, the Eurocodes do not provide a simplified method for the fire resistance assessment. The literature offers a simplified method for computation of bending resistance under elevated temperature, based on existing research on thermal models, and was validated for a particular type of slim floor beams (SFB). The current study extends the scope of application of this method, for different types of slim floor beam, which include an asymmetric double -T steel cross-section. The objective was reached through a numerical procedure, by analyzing 162 configurations subjected to four different fire requirements (R30, R60, R90, R120), resulting in a total of 648 analyses, performed with a validated numerical model in SAFIR software. The results in terms of bending resistance showed that the simplified method represents a strong tool for the fire design of slim floor beams.
... In a recent study, Mahari et al. [7] focused on seismic retrofitting methods for the JASs. Static and seismic design and construction of one-and two-way JASs were also examined in previous studies [8,9,10,11]. ...
... Therefore, the masonry JASs play an important role in seismic response of the structure. As indicated by Mahari and Rahmani [9], the seismic performance of the slabs is the main determinant of the structural performance of the whole structure. One of the typical weaknesses of the one-way JASs is the tensile strength. ...
After the industrial revolution, the use of jack arch slabs (JAS) was quite common in many historical structures with the availability of iron and steel in structural engineering field. JAS is a composite system of steel I-beams and masonry bricks, which are placed between steel I-beams. This study focuses on the structural failures and weaknesses of masonry structures with JAS. The aims of this paper are to deeply illustrate the structural vulnerability of masonry JAS and to summarize the positive and negative effects of JAS on structural behavior. Within the scope of this study, this study focuses on historical American Boarding School for Girls in Merzifon, Turkey, which has one-way masonry JAS. It essentially assesses the structural behavior of the school and investigates the seismic vulnerability of JASs. For this purpose, the mechanical properties of the structural materials have been primarily evaluated with experimental tests. Then the finite element analyses have been carried out with the use of three dimension numerical model in order to investigate the structural behavior of the structure.
