Expanded Metal Mesh Research Articles

Performance of Crumb Rubber and Nano Fly Ash Based Ferro-Geopolymer Panels under Impact Load

This paper presents an experimental investigation into the impact performance of Ferro-cement panels incorporating a significant proportion of geopolymer mortar. This panel could be an effective replacement for prefabricated roof and floor deck construction elements. In this study, the geopolymer mortar includes wastes disposed from industries like ground granulated blast furnace slag (GGBFS) and flyash as their base material which contributes to reduced CO2 emission. The pore filling and element densifying mechanism is enhanced by the addition of Nano flyash. The fine aggregate is replaced up to 5% with treated tyre crumb rubber which can be utilized as a sustainable construction material. The cast panel was cured at 80oC for 48 hours in the oven. The incorporation of Expanded Metal Mesh into geopolymer mortar results in higher impact load absorption capacity rather than other kind of reinforcing meshes. The GGBFS based Geopolymer results in 17% higher compressive strength than fly ash based geopolymer because of its good bonding nature. The Nano fly ash based geopolymer gives 35 MPa in compressive strength and 902.52 joules in impact energy absorption which is greatest among all panels because of its densifying effect of mortar.

Performance of Crumb Rubber Incorporated Ferro Geopolymer Panels under Flexure

This research work presents the overview of geopolymer mortar application into the ferro cement panel with the incorporation of crumb rubber and Nano fly ash. The geopolymer mortar is prepared by using industrial wastes as a base material such as fly ash and ground granulated blast furnace slag (GGBFS) which generally helps to reduce the level of CO2 emission. Also, the recycled tyre crumb rubber is utilized as a sustainable innovative construction material which is used a partial substitution for sand upto 5% for enhancing the ductility without any strength degradation. These reduces land fill problems and ground water quality degradation problems. Crumb rubber has the ideal capacity to absorb energy from static and other kind of loads. The geopolymer binder preparation is done by utilizing material such as fly ash, GGBFS, alkaline liquid made of NaOH and Na2SiO3 , Nano fly ash. The Nano fly ash is used as an additive which helps in increasing the strength and durability of the element by its pore filling capability. This project aims to enhance the strength of fly ash based geopolymer mortar with the help of GGBFS incorporation. The molarity of alkaline activator, solution to binder ratio and silicate to hydroxide ratio is fixed as 12, 0.4 and 1.5 throughout the process. The mortar cubes and panels were heat cured under hot air oven at 80ᵒ C for 48 hours. The mechanical behavior of geopolymer mortar is assessed by compressive strength test water absorption test. The panel is made of high strength geopolymer mortar and expanded metal mesh with chicken mesh for obtaining higher energy absorption capacity with good deforming ability and less crack pronouncement. The investigation involves finding the initial crack load, ultimate failure load and residual flexural strength ratio. The results show that the tyre inclusion enhances the flexural strength of the ferro geopolymer panel by means of its ductile enhancing capacity

Determination of geometric parameters for rational load-bearing unit of bridge cylindrical column pier

This paper deals with a bridge pier energywise uniform strength cylindrical steel-concrete load-bearing unit having a mesh case, which is made of an expanded metal mesh, as the most rational and the least resource-demanding one, using the nonwaste technology. The rational parameter selection method, which guarantees cross section uniform strength for the suggested load-bearing unit, is provided. The concrete core of the given element is a hollow cylindrical element that varies in height and whose centre of gravity coincides with an external loading point for any horizontal cross section. In addition to uniform strength, the hollow enables you to control the centre of gravity of the given complicated compound cross section of a cylindrical steel-concrete load-bearing unit. The calculation method to determine the main geometric parameters of the uniform strength load-bearing unit of a bridge cylindrical column pier having the lateral cross section area that varies in height is provided. The geometric parameters are the centre of gravity and its coordinates, central inertia moments and the radius of inertia. To exclude an impact of random eccentricity on a complicated compound cross section of a pier uniform strength steel-concrete load-bearing unit, the method to design a cross section core is provided.

Effect of Strengthening Axially Loaded Circular Self-Consolidating Short Columns with Expanded Metal Mesh

Superior confinement for concrete column cannot be provided by traditional lateral ties reinforcement due convergence of bends and twists caused due to lateral reinforcement. In this paper, the enhancement in confining the steel bars due to the utilization of metal mesh any case to the regular tie reinforcement is studied. Totally 5 column specimens were cast and cured. A control specimen was prepared and remaining 4 specimens were internally wrapped using Expanded Metal Mesh (EMM). Mesh Apertures are differed having constant mesh thickness. Self-Consolidating Concrete was adopted in place of congested reinforcement. The specimens were tested under uniaxial compression in universal testing machine until failure. The results show that the strength and ductility has been improved for internally confined concrete column specimens.

Statistical characterisation of expanded metal mesh strand, to propose a correlation between properties of parent material and finish product, EMM

The use of steel plate shear walls (SPSW) for the design of structures under low seismic intensity results in very thin infill SPSW panels. Construction of such structures is infeasible, mainly due to the difficulty in connecting the infill to the boundary members. Thus, a designer is compelled to use a thicker infill section which in turn leads to heavier boundary elements. In order to overcome this constraint of design, a new type of infill panel using Expanded Metal Mesh (EMM) is studied as an alternative in place of a solid infill SPSW panel. Available codes on expanded metal mesh specify requirements of workmanship, quality control, etc. but neither recommend the strength of expanded metal mesh as a whole nor the strength of its components. Thus, it is necessary to perform extensive tests to extract the strength of expanded metal mesh as a whole in terms of the strength of its components and to come out with a correlation between the strength of the parent material (material from which EMM is manufactured) and that of the finished product (EMM). This paper a) presents the statistical characterization of EMM strands, b) recommends nominal design values for basic mechanical properties and c) proposes the correlation between the strength of the parent material and that of EMM strand.

The Influence on Daylight and Energy Consumption of Expanded Metal Mesh Applied on Building Façades

Expanded metal mesh has become widely used as a shading element in the façade of many buildings in recent years, and its energy saving performance has been evaluated in tropical/subtropical countries. However, expanded metal mesh reduces solar radiation while also reducing the natural daylight entering the building. This study’s objective is to assess the impact of expanded metal mesh on building energy consumption and natural daylighting. The daylight effects on visual comfort and energy consumption of an office building located in Tainan, Taiwan were studied via building simulation program DIVA. Parameters including window to wall ratios (WWR), perforation rate expanded metal mesh, and glazing of window glass were studied, and a daylight standard of LEED rating system was used for evaluation. The results showed that when the office building with large WWR and less glazing, the expanded metal mesh performed a better energy saving effect. For an office building with 50% WWR, the laminated clear glass and expanded metal mesh with 21% perforation rate were suggested to be the best design solution for meeting the LEED daylight standard and the lowest energy consumption.

Flexural behaviour and theoretical prediction of lightweight ferrocement composite beams

Sixteen full-scale simply supported composite beams of the same dimensions, breadth = 100 mm, thickness, 200 mm, and length of 2000 mm, subjected to flexural loading, were experimentally tested and their structural parameters, namely, pre-crack stiffness, serviceability loads, post-cracking loads, energy absorption, ultimate load-to weight ratio, and compressive strains were investigated. In addition, theoretical prediction of ultimate loads was carried out to adopt a theoretical approach as a design methodology for ferrocement elements. Experimental results showed that pre-crack stiffness, maximum service loads, maximum values of energy absorption and ultimate loads to weight ratios of ferrocement beams are higher than that of lightweight control beam by up to 46%, 32%, 64.4% and 32.8%, respectively. Higher post-cracking loads were exhibited by beams reinforced by expanded metal mesh, compared to those reinforced by welded wire mesh regardless of the core filling type. For post cracking load indicator, confinement with expanded metal mesh was the decisive factor affecting the post-cracking load capacity. Beams reinforced with expanded metal mesh showed higher energy absorption than those of the other beams reinforced with welded wire mesh or fiberglass mesh. Increasing the amount of mesh reinforcement results in higher energy absorption for beams made of Autoclaved Aerated Lightweight Brick Core (AAC). Generally, the maximum compressive strains of the ferrocement composite beams were generated at higher loads compared to those of the control beams. Theoretical calculations, based on the assumption of strains and forces distribution block, results in acceptable prediction of the ultimate loads. The ratio of experimental to theoretical ultimate loads ranges from 0.91 to 1.26. This study showed that ferrocement composite beams may be used as an alternative to traditional reinforced normal or lightweight concrete beams after careful choice of the combination of core and mesh types to suit the application in question.

Forced under-rib water removal by using expanded metal mesh as flow fields for air-breathing direct methanol fuel cells

Water management is a critical issue to be solved efficiently for an air-breathing direct methanol fuel cell (DMFC). The cell performance decreases sharply once the water flooding occurs. In this paper, a novel strategy of water removal is proposed by incorporating a functional self-made expanded metal mesh, which can be used as the cathode flow field in a DMFC. Experiments show that water can be directly discharged in the form of water film or water line from the water outlet to the bottom underneath the expanded mesh. The water management can be further improved by using absorbent cottons, suitable feed rates and an upright texture direction of the metal mesh. Results also show that only a few mesh openings are blocked by water when the tested device tilts from 60° to 120°. In a real DMFC, the expanded mesh displays an excellent ability in water removal compared to the traditional perforated flow fields. The cathode water only gathers at the bottom and covers very few mesh openings. This new method helps efficiently avoid the issue of water flooding at the cathode using the expanded mesh.

Efficient modeling of optically-complex, non-coplanar exterior shading: Validation of matrix algebraic methods

It has long been established that shading windows with overhangs, fins, and other types of non-coplanar systems (NCS) is one of the most effective ways of controlling solar heat gains in buildings because they intercept solar radiation prior to entry into the building. Designers however often specify non-opaque materials (e.g., louvers, fritted glass, expanded metal mesh) for these systems in order to admit daylight, reduce lighting energy use, and improve indoor environmental quality. Most simulation tools rely on geometric calculations and radiosity methods to model the solar heat gain impacts of NCS and cannot model optically-complex materials or geometries. For daylighting analysis, optically-complex NCS can be modeled using matrix algebraic methods, although time-efficient parametric analysis has not yet been implemented. Determining the best design and/or material for static or operable NCS that minimize cooling, heating, and lighting energy use and peak demand requires an iterative process. This study describes and validates a matrix algebraic method that enables parametric energy analysis of NCS. Such capabilities would be useful not only for design but also for development of prescriptive energy-efficiency standards, rating and labeling systems for commercial products, development of design guidelines, and development of more optimal NCS technologies.A facade or “F” matrix, which maps the transfer of flux from the NCS to the surface of the window, is introduced and its use is explained. A field study was conducted in a full-scale outdoor testbed to measure the daylight performance of an operable drop-arm awning. Simulated data were compared to measured data in order to validate the models. Results demonstrated model accuracy: simulated workplane illuminance was within 11–13%, surface luminance was within 16–18%, and the daylight glare probability was within 6–9% of measured results. Methods used to achieve accurate results are discussed. Results of the validation of daylighting performance are applicable to solar heat gain performance. Since exterior shading can also significantly reduce peak demand, these models enable stakeholders to more accurately assess HVAC and lighting impacts in support of grid management and resiliency goals.

Experimental and numerical study of the behavior of RC slabs with openings reinforced by metal mesh under impact loading

The main objective of the following work is to inspect the effect of reinforcing metal mesh on the behavior of slabs with openings under impact loadings. Based on an earlier numerical study by Shaheen et al. (2017), slabs with mid-side openings revealed the worst behavior regarding to deflection and cracked pattern when subjected to impact loading compared to other slabs with different locations of openings. Hence, the present work focuses specifically on this type of slabs and the variation in their behavior when reinforced by welded or expanded metal mesh. Seven specimens were prepared and tested in Faculty of Engineering, Menoufia University, Egypt. Moreover, a FE model for the slabs was built using Abaqus 6.14 and verified against test results. It was found that expanded metal mesh had a significant effect on reducing deflection due to impact load as well as controlling of cracks in contrast with welded metal mesh.

Evaluation of stresses and deflections in expanded metal plates subjected to transverse loading

The implementation of rigid and lightweight structures that perform support functions has their main field of application in the industrial sector. These structures must satisfy all requirements of security and comfort, besides being profitable for the company using them, at the time of procurement and maintenance. This paper aims at studying the behavior of expanded metal meshes subject to transverse loading, determining the deflections produced by this type of loading. In this study, design recommendations for the use and installation of expanded metal meshes provided by Standard EMMA 557-15 are considered. Therefore, a finite element model is developed considering linear behavior of material and geometry, employing the commercial software ANSYS. Solid elements are used in the generation of the computational model where metal sheets are subject to transverse loads to determine the deflections in the mesh. Next, the influence of the following parameters is evaluated: material properties, span between structural supports, magnitude and type of the transverse load (concentrated or uniform), size of pattern, and orientation of the mesh. Finally, numerical results show that deflections found in expanded metal meshes are clearly affected by the aforementioned parameters.

Flexural characteristics of lightweight ferrocement beams with various types of core materials and mesh reinforcement

Sixteen reinforced concrete beams having the cross-sectional dimensions of 100 × 200 × 2000 mm and clear span of 1800 mm were cast and tested until failure under a single mid-span concentrated load. Ferrocement beams in this research contained either an Autoclaved Aerated lightweight brick Core (AAC), Extruded Foam Core (EFC), or a Lightweight Concrete Core (LWC); and were reinforced with either Expanded Metal Mesh (EMM), Welded Wire Mesh (WWM) or Fibre Glass Mesh (FGM). Structural behaviour of studied beams, including first crack, ultimate load, deflection, ductility index, strain characteristics, crack pattern and failure mode were investigated. Experimental work results showed that ferrocement beams exhibited higher ductility indices than those of the control normal and lightweight test beams to different degrees. Ferrocement beams made of EFC core generally gave the lowest ductility index while the highest ductility index was found for beams made of AAC and LWC cores. Ferrocement beams demonstrated better crack control and did not undergo spalling as opposed to the conventional beams. Specimens reinforced by EMM showed better ductility than those reinforced by WWM and even after increasing the reinforcement ratio of WWM, the situation did not change. Specimens reinforced by FGM had the lowest ductility compared to specimens reinforced by steel mesh. Cracks were found to develop more rapidly in beams reinforced by EMM, while beams reinforced by FGM exhibited the least amount of cracks. The results of this research showed that ferrocement beams of light weight cores may be promising as an alternative to conventional beams and may be viable alternatives especially for low cost residential buildings.

Direct Tension Test on Expanded Metal Mesh and Welded Square Mesh for Ferrocement Composite

Direct Tension Test on Expanded Metal Mesh and Welded Square Mesh for Ferrocement Composite

Structural effects of expanded metal mesh used as a flow field for a passive direct methanol fuel cell

The metal expanded mesh is an attractive alternative to be flow field plate of the direct methanol fuel cell (DMFC) for practical applications. This work investigates the structural effects of the stainless-steel expanded mesh used as a flow field in a passive DMFC. Three expanded meshes with different strand widths are tested at various methanol concentrations. Effects of its assembly diversity, in terms of two different mesh surfaces and orientations of the opening mesh, are also explored at both the anode and cathode. The influential mechanisms in the light of reactants and products management are analyzed by use of a visualization method. The mesh with a smaller strand width yields a better cell performance at a lower methanol concentration, which performs worse at a higher methanol concentration. Compared with the traditional perforated flow fields, the expanded mesh is preferred at lower methanol concentrations. The assembly mode combining BU at the anode and BL at the cathode is recommended. The visualization tests at both sides reveal the positive effects of above optimal configuration on the reactants and products management in a passive DMFC.

Effectiveness of Combined Confinement with Metal Meshes and Ties for Preloaded and Post-Heated RC Short Columns

Recently, innovative materials are used as lateral confinement reinforcement to increase concrete core contribution to load carrying capacity of reinforced concrete (RC) columns. This paper presents experimental assessment for the effectiveness of practical lateral confinement that utilizes metal meshes combined with typical steel ties for RC columns. The experimental plan comprises thirty square short column specimens and investigates two metal meshes types: expanded metal mesh (EMM) and welded wire mesh (WWM). Preloading and post-heating were considered in the experimental study to provide realistic assessment for proposed confinement in real and fire conditions. Prior to testing under monotonic axial compression, all column specimens were subjected to preloading with 65% (of reference column capacity) in addition to post-heating for only fourteen specimens. The lateral reinforcement consisted of metal mesh layers (either EMM or WWM) wrapped above steel ties of various volumetric ratios (\(\rho =0.333\), 0.167% and zero). Results showed that column load capacity was increased (49.15–2.72%) for all specimens enclosing proposed lateral reinforcement with respect to reference specimens whose lateral reinforcement comprising only ties (\(\rho =0.333\)%). Also, the ductility was noticeably improved. Results revealed that metal mesh strength had the upper hand in magnifying ultimate load and ductility. Moreover, optimum lateral reinforcement (that develops significant improvement in load capacity and ductility without degradation of stiffness) was determined. Metal meshes enhanced fire resistance by dropping concrete core temperature and mitigating ultimate load reduction of post-heated RC columns compared to reference specimens.

Characterisation of platinum electrodeposits on a titanium micromesh stack in a rectangular channel flow cell

Platinised titanium mesh is a common electrode material in industrial electrolytic cells and Ce-based redox flow batteries. In this work, the electrodeposition of platinum on a stack of titanium micromeshes is performed from a flowing alkaline solution in a rectangular channel, divided flow cell. The morphology and distribution of the resulting platinum deposits are studied by SEM, EDS mapping and X-ray computed tomography. The active surface area of the electrode was assessed from the charge transfer current for the reduction of Ce(IV) ions and compared to that of planar and expanded metal mesh electrodes. The surface area was estimated by hydrogen electrosorption relative to that at a planar Pt/Ti electrode. As expected from the potential drop within the electrode channel, the individual micromesh near the cell separator showed a higher platinum content. Pt/Ti micromesh offers an extended surface area and enhanced mass transport compared to planar electrodes and conventional expanded metal mesh anodes. The applications for these and alternative electrode structures are discussed.

Quasi-static test and strut-and-tie modeling of precast concrete shear walls with grouted lap-spliced connections

This paper discusses the seismic performance of nine full-scale shear walls including seven precast specimens and two cast-in-place specimens. The precast specimens were designed to emulate monolithic cast-in-place specimens. The precast upper shear wall and the base were connected at their interface through lap splice that one of the spliced bar was embedded into a grout-filled hole, which was reserved by metal bellow or expanded metal mesh. The geometries and reinforcement of precast specimens were identical with those of corresponding cast-in-place specimens in each group. But their stirrups were different. Based on the two types of grouted connections, the specimens were tested under low cyclic lateral loading to study their seismic performance by comparing their carrying capacities, crack patterns, ductility, hysteretic curves and energy dissipation. In general, shear walls with metal bellows at the joint exhibited better structural behaviour than the shear walls with expanded metal mesh due to their well confined effect on the spliced bars and surrounding concrete. Thus, this kind of precast connection may emulate cast-in-place connection. Lastly, a reasonable strut-and-tie model was developed based on ACI 318-14 code to investigate the force transfer mechanism of the precast shear wall. The calculated results were compared with the test results and the shear strength results calculated by empirical expression in the ACI 318-14 code.

Performance of passive DMFC with expanded metal mesh current collectors

This article assesses the feasibility of the expanded metal mesh as the current collector in the passive direct methanol fuel cell (DMFC). A single passive DMFC fixture is designed and fabricated. An acrylic supporting plate is incorporated in the cell fixture for compressing the EMCC against MEA to achieve a proper contact between the MEA and expanded metal mesh current collector (EMCC). The performance of the passive DMFC is carried out and compared with different combinations of the supporting plates and EMCCs. For this purpose, open circuit voltage, the polarization test, and electrochemical impedance spectroscopy are conducted. It is found that the configurations of the supporting plate affect the performance of the cell, and the maximum performance can be achieved by optimizing its open ratio by varying the rib configuration and rib thickness. The results reveal that the passive DMFC with EMCC gives better performance as compared to the conventional passive DMFC with circular perforated current collector and the EMCC also facilitates more fuel spreading at anode catalyst layer and increases operating temperature. Furthermore, it is seen that the mesh type and geometry of the EMCC affect the cell performance, and the passive DMFC with the coarse mesh, wider strand width and thicker EMCC produce better cell performance.

Improved confinement of reinforced concrete columns

Abstract Traditional steel ties reinforcement cannot provide superior confinement for reinforced concrete (RC) columns due to the constraints on tie spacing and disturbance of concrete continuity. This paper presents a practical confinement configuration consisting of single Expanded Metal Mesh (EMM) layer in additional to regular tie reinforcement. The EMM layer is warped above ties. The proposed transverse reinforcement, with various volumetric ratios of ties, was investigated in sixteen square short RC column specimens categorized in two groups according to their slenderness ratios. The specimens were cast in vertical position simulating the construction field and they were tested under concentric compression till failure. The results indicated that the columns, confined with proposed lateral reinforcement, revealed significant improvement in the strength and ductility. Also, high reduction in ties volumetric ratio with no loss in ultimate load could be achieved by installing the EMM layer.

Melting of phase change material assisted by expanded metal mesh

Accelerating the melting of phase change material (PCM) via metal foam impregnation is an established method. In this work, it is proposed to use expanded metal mesh (EMM) as an inexpensive alternative. Raised aluminium EMM sheet was cut into five layers, arranged perpendicularly and attached with wire columns, creating a 90% porosity unit. Salt hydrate PCM, which melted at 46 °C, filled the void space creating a PCM/EMM composite. The composite was heated at 55 °C, and the melt completion time was compared with the control i.e. pure PCM. It was found that EMM reduced the melting time by 14%, which could be increased if better thermal interfaces such as soldering or brazing were used. Small scale modelling compared very well with the experimental results, which verified its viability to model PCM/EMM systems. Simulation showed that an excellently contacting EMM layers arranged in parallel, resulted in an 81% melting time reduction, far superior than any metal foam/PCM performances to date. EMM is a promising concept in enhancing heat transfer in PCM, which requires further studies to optimize the performance.