Welded Wire Mesh Research Articles

Experimental and numerical investigation on RC beams with web openings subjected to pure torsion strengthened by ferrocement technique or GFRP sheets

The main objective of the current experimental and numerical study is to investigate the effect of strengthening by ferrocement layers on the behavior of reinforced concrete (RC) beams with openings subjected to pure torsion and compare it with the beams that were strengthened by Glass Fiber Reinforced Polymer (GFRP). The experimental investigation consists of twelve reinforced concrete (RC) beams that have been divided into four groups. The parameters under investigation included the strengthening technique (ferrocement or External Bonded Glass Fiber Reinforced Polymer EB-GFRP), type of steel mesh (welded wire mesh and expanded metal mesh), number of layers of mesh (1, 2, 3), extension length outside opening (50, 100 or 200) mm, strengthening configuration (full or U-shape) wrapping, and the anchoring system effect. The experimental work consists of one solid beam and eleven beams with openings. The tested beams yielded results such as cracking and ultimate torques, angle of rotation, and mechanism of failure. Creating an opening in the control solid beam resulted in a 38.46 % decrease in ultimate torque, while using different techniques during this research proved efficiency in the strengthening process. Using GFRP U-wrapping and fully wrapping to strengthen the area around the beam's opening increased the ultimate torque by 50 % and 81.25 %, respectively, compared to the un-strengthened beam with an opening. Adding fully wrapped ferrocement layers to the beam with an opening greatly improved its torsional strength. The ultimate torque increased by 40.63 % to 81.25 % compared to the beam with an unreinforced opening. Increasing the number of welded steel mesh layers from 1 to 3 in the ferrocement strengthening technique led to an increase in ultimate torque from 40.63 % to 75 % compared with the un-strengthened beam with the opening. The tests showed that using expanded metal mesh instead of welded wire mesh in strengthened beams with holes led to a 9.43 % higher ultimate torsional capacity, indicating that the expanded metal mesh worked better than the welded wire mesh. Using the U-shape ferrocement wrapping with anchors was better than without anchors, resulting in a 9.1 % increase in the ultimate torsional capacity. Applying a fully wrapped GFRP sheet or expanded metal mesh ferrocement strengthening achieved the highest ultimate torque, 81.25 % more than the un-strengthened beam with an opening. Moreover, a 3D non-linear finite element analysis is conducted using ABAQUS software to forecast the torsional properties of beams strengthened by either ferrocement or EB-GFRP. The numerical model captured the failure patterns, twisting angle, and ultimate load of tested beams. The experimental and analytical results were in good agreement. The research concluded the effectiveness of using the ferrocement reinforced with different steel mesh types in strengthening reinforced concrete beams with openings under pure torsion, the cost-efficiency and simplicity of ferrocement as a solution compared to its results with EB-GFRP techniques.

The Structural Behavior of Lightweight Self-Compacting Concrete Slabs Using Different Types of Reinforcement

The purpose of this study is to examine how the type of reinforcement used in self-compacting concrete (SCC) and lightweight self-compacting concrete (LWSCC) affects their structural behavior. There were three forms of reinforcement used: wire mesh, glass fiber-reinforced rebars, and regular steel rebars. To evaluate the mechanical characteristics of reinforced concrete slabs with various types of reinforcement, extensive experiments were carried out. The tensile strength, stiffness, and crack resistance of the concrete were studied in each case. The finite element program Abaqus was utilized in addition to the experimental investigations to create the numerical simulation of the test. The experimental results revealed that the reinforcement type significantly affects the structural behavior of SCC and LWSCC slabs. Conventional steel rebars provided high tensile strength and excellent crack resistance, while glass fiber-reinforced rebars contributed to enhanced flexibility and reduced overall weight of the concrete. On the other hand, the wire mesh exhibited average mechanical and structural properties. These findings emphasize the importance of selecting the appropriate reinforcement type based on specific applications and desired performance requirements. This research provides valuable guidance for architects and civil engineers in choosing optimal reinforcement for SCC and LWSCC. Furthermore, it can contribute to the advancement of techniques and potential improvements in these materials to achieve better performance and enhance sustainability in infrastructure and building construction. From the practical results, it was found that in the case of using lightweight self-compacting concrete and self-compacting concrete, it is preferable to reinforce it with ordinary reinforcement steel, as it gives the best results in terms of maximum load capacity at failure. Although the use of steel reinforcement in self-compacting concrete also gives the best results, but from the laboratory results it is possible to improve the performance of self-compacting concrete by reinforcing it with GFRP or welded wire mesh.

Experimental investigation of heat-damaged reinforced concrete columns strengthened with different schemes

This paper experimentally investigates the efficacy of two jacketing techniques in the rehabilitation of square and circular reinforced concrete (RC) columns that were exposed to highly elevated temperatures. Twenty-four RC columns were tested under an axial compression load, which was divided into three groups. The first group consisted of the control specimens without applying any strengthening approach. Group 2 consisted of the columns with the strengthening configuration of near-surface-mounted (NSM) rebars and carbon fiber-reinforced polymer (CFRP) layers. Regarding the third group, columns were strengthened using two layers of welded-wire mesh (WWM) and ultra-high-performance fiber concrete (UHPFC) jacketing. Four columns from each group were subjected to an elevated temperature of 600 °C for a duration of 3 h, while the remaining half were subjected to room temperature. The results showed that after three hours at a temperature of 600 °C, both strengthening schemes successfully restored and exceeded the initial load-carrying capability of all columns. Utilizing WWM with UHPFC jacketing as new strengthening technique proved to be the most efficient method for reinstating the load-carrying capability of circular columns (+321.8 %) and square columns (+140.6 %) that were subjected to high temperatures. Additionally, an analytical model was proposed to estimate the ultimate load capacity of RC columns after rehabilitation.

Shear Behavior of Reactive Powder Concrete Ferrocement Beams with Light Weight Core Material

In this paper, the shear behavior of ferro-cement hollow beams is investigated experimentally and analytically. Ten reinforced concrete beams with cross-sectional dimensions of 100 × 200 × 1300 mm and a clear span of 1000 mm were cast and tested until failure under a two-point loading system. Ferrocement beams in this research contained either an autoclaved aerated lightweight brick core (AAC) or an extruded foam core (EFC) and were reinforced with either expanded metal mesh (EMM) or welded wire mesh (WWM). The structural behavior of the studied beams, including first crack, deflection, ultimate load, crack pattern, failure mode, and ductility index, was investigated. The experimental data were used to validate finite element models created with the ABAQUS finite element program. It can be concluded that the optimum performance of ferrocement beams can be achieved using beams with a second layer of expanded steel mesh as additional reinforcement, which led to an increase in the ultimate load and maximum deflection by 12.9% and 22.8%, respectively. Furthermore, the Numerical results agreed with the experimental results, where the ratio between the NLFE ultimate loads and the experimental ultimate loads varies between 1.02 and 1.07, with an average ratio of 1.04.

Experimental and numerical investigations of the shear performance of reinforced concrete deep beams strengthened with hybrid SHCC-mesh

This paper investigates the shear strengthening of simply supported deep beams using welded wire mesh and glass fiber mesh filled with strain-hardening cementitious composites (SHCC) concrete. Nine reinforced concrete (RC) deep beams were tested in this study to investigate different shear-strengthening techniques including the type of mesh (glass fiber mesh and welded steel wire mesh), number of layers (single and double), and the effects of additional anchor using high-strength bolts on the shear performance of RC deep beams. The results showed the SHCC-mesh jackets increased the ultimate load of the deep beams by up to 82 %, cracking load by up to 73 %, elastic stiffness by up to 457 %, and energy absorption by up to 380 % compared to the unstrengthen control beam. Furthermore, the welded wire mesh provided greater enhancements of strength, stiffness, and energy absorption than the glass fiber mesh. In addition, anchoring the jackets further improved the strengthening efficiency. Advanced nonlinear three-dimensional finite element models were also simulated to capture the structural responses of the RC deep beams strengthened using welded wire mesh and glass fiber mesh. It was found that the numerical models accurately predicted the behavior of the beams upon validation against the experimental results.

Structural Performance of Ferrocement Hollow Shear Walls Subjected to Lateral and Compressive Axial Loads

In this study, ten shear walls were experimentally tested to examine behaviour of ferrocement hollow shear walls subjected to axial and lateral loads. Ferrocement mortar (FM) was used to build eight walls, while normal concrete (NC) was used to build two controls. Walls were lateral reinforced using conventional stirrups, two layers of welded wire mesh (WWM), and expanded steel mesh (ESM). Two specimens lacked lateral reinforcement except for one transverse web in the center of the inner hole. Two symmetric groups of five walls each were created by dividing the walls. While the other group was loaded laterally, one group was loaded axially. In each group, the load–displacement relationship, maximum load and associated displacement, stiffness, ductility, and failure mechanism of FM and NC walls were compared. The results showed that FM walls provided with ESM and WWM had ultimate axial loads that were, respectively, 36% and 19% higher than NC control walls. Ultimate lateral loads and related ultimate drifts of FM walls reinforced with two layers of WWM and ESM were, respectively, 68% and 39%, 96% and 43.5%, larger than control NC wall. For lateral loads greater than those applied to the NC control wall, stiffness increase ratios for FM walls ranged from 2.5% to 89.5%, and for axial loads, they ranged from 20% to 150.5%. The ductility of FM walls increased when compared to NC walls by 58.5% and 158.8% for axial and lateral loading, respectively, when two layers of WWM were utilized to lateral reinforce FM walls. When two layers of ESM were applied to laterally reinforce FM walls in comparison to an NC wall, this increased the walls' ductility under axial and lateral loads by 110.5% and 214.7%, respectively.

Retrofitting of heat-damaged fiber-reinforced concrete cylinders using welded wire mesh configurations

Abstract Fire damage poses a significant risk to reinforced concrete structures throughout their lifespan. Fire exposure influences the stress-strain properties and durability of concrete, despite its non-flammability. Therefore, the strengthening approach is an economic option for lengthening their lifespan. This paper aims to conduct an experimental investigation into retrofitting heat-damaged fiber-reinforced concrete cylinders using welded wire mesh (WWM) configurations. Four concrete mixes were investigated. In total, 48 concrete cylinders were tested under axial compression until failure. The primary variables considered in the testing program consisted of (i) the influence of various fiber types (steel fiber (SF), polypropylene (PP), and hybrid fibers (SF+PP)); (ii) exposure temperature (26°C and 600°C); and (iii) WWM strengthening. Exposure to a temperature of 600°C led to a significant reduction in the compressive strength, ranging from 23.7% to 53.3%, while the inclusion of fibers has a substantial effect on the compressive strength of concrete, regardless of fiber type, with an increased ratio reaching up to 34.7%. The finding also clearly shows that the strengthening of heat-damaged specimens with WWM jacketing resulted in a 38.8%, 4.9%, and 9.4% increase in compressive strength for SF, PP, and SF+PPF specimens, respectively, compared to unheated control specimens. The suggested approaches to strengthening, which involve the use of WWM jacketing with two layers, successfully restored and surpassed the initial concrete compressive strength of the specimens that were damaged due to exposure to high temperatures.

Comparative study of eco-friendly wire mesh configurations to enhance sustainability in reinforced concrete structures

Recent and past studies mainly focus on reducing the dead weight of structure; therefore, they considered lightweight aggregate concrete (LWAC) which reduces the dead weight but also affects the strength parameters. Therefore, the current study aims to use varied steel wire meshes to investigate the effects of LWAC on mechanical properties. Three types of steel wire mesh are used such as hexagonal (chicken), welded square, and expanded metal mesh, in various layers and orientations in LWAC. Numerous mechanical characteristics were examined, including energy absorption (EA), compressive strength (CS), and flexural strength (FS). A total of ninety prisms and thirty-three cubes were made. For the FS test, forty-five 100 × 100 × 500 mm prism samples were poured, thirty-three 150 × 150 × 150 mm cube samples were made, and forty-five 400 × 300 × 75 mm EA specimens were costed for fourteen days of curing. The experimental findings demonstrate that the FS was enhanced by adding additional forces that spread the forces over the section. One layer of chicken, welded, and expanded metal mesh enhances the FS by 52.96%, 23.76%, and 22.2%, respectively. In comparison to the remaining layers, the FS in a single-layer hexagonal wire mesh has the maximum strength, 29.49 MPa. The hexagonal wire mesh with a single layer had the greatest CS, measuring 36.56 MPa. When all three types of meshes are combined, the CS does not vary in this way and is estimated to be 29.79 MPa. In the combination of three layers, the chicken and expanded wire mesh had the most energy recorded prior to final failure, which was 1425.6 and 1108.7 J, whereas it was found the highest 752.3 J for welded square wire mesh. The energy absorption for the first layer with hexagonal wire mesh increased by 82.81% prior to the crack and by 88.34% prior to the ultimate failure. Overall, it was determined and suggested that hexagonal wire mesh works better than expanded and welded wire meshes.

Wildlife fencing at German highways and federal roads – requirements and management implications

In Germany, the high risk of wildlife–vehicle collisions (WVC) is further increasing due to increasing traffic volumes and road densities as well as the growing population densities of common ungulate species. As a result, threats to human health and property as well as wildlife mortality of widely spread and rare species increase. Currently, three basic types of wildlife fences are used in Germany: type A, a conventional galvanized‐high tensile deer fence (made of knot braid); type B, a chain wire (mesh wire) fence; type C, a rigid welded wire mesh fence panels. Since fencing needs to restrict access of many different species with different behaviours (e.g. jumping, climbing, digging), fencing needs to be multifaceted to be effectively. Furthermore, the occurrence of wildlife species with habits such as jumping, climbing or digging determines the optimal (functional) fence design per location. We surveyed road managers in combination with a personal assessment of road sections in Germany and derived the following recommendations for optimal fencing to reduce WVC: 1) To deter digging, use plates made of recycled synthetic materials or a concrete foundation, instead of barbed wire. 2) Fencing should be made of chain wire (mesh wire, type B) fence or rigid welded wire mesh fence panels (type C) instead of knot braid mesh (type A). 3) To restrict climbing, use angled chain wire fence or rigid welded wire mesh fence panels at the top of the fences. 4) Maintain fences so that they are kept free from ingrown vegetation/woods. Maintenance conditions should be considered while planning and building the fence, especially to ensure sufficient space on both sides for accessibility. 5) Fencing should be established preferably near the roadside and moved away from property lines. In conclusion, wildlife fencing could be a very effective mitigation measure to prevent WVC with common as well as protected species, when proper designed and recommendations of the survey will be consequently considered. Currently many wildlife fences lack functionality due to an inappropriate design and maintenance issues in Germany.

Influence of shear strengthening of reinforced normal concrete beams incorporating sustainable materials

AbstractThis research studies shear strengthening performance for Normal Concrete (NC) beams employing Engineered Cementitious Composite (ECC) reinforced with Galvanized Welded Wire Mesh (GWWM) in conjunction with/without a prestressing system. Six full‐scale Reinforced Concrete (RC) beams were experimented under static monotonic loading at critical shear span zone up to collapse. The investigated factors were: the type and technique of strengthening, materials used for strengthening, and size and configuration of shear reinforcement. Two techniques were introduced: ECC layer reinforced with GWWM and pretensioned steel bars recovered by ECC with one GWWM. GWWM with and without pretensioned steel bars were delivered as shear reinforcement for strengthening. Vertical and inclined steel bars were the two configurations selected for the prestressing technique for suppressing shear stress. The study was discussed through the experimented beams' crack load and pattern, collapse mode, elastic stiffness, absorbed energy, initial cracking load, and ultimate load, along with the corresponding defection. Experimental results showed that both exploited techniques could govern crack patterns, enhance the failure mode, and upgrade ultimate loading capacity up to 52%. Finite element models were built up, simulating those strengthened with an ECC covering layer augmented with GWWM extracting a model with an error of about 3%.

Shear behavior of concrete panels reinforced with GFRP bars under cyclic diagonal tension tests

Glass Fiber Reinforced Polymer (GFRP) bars aims to improve the properties of concrete conventional reinforcement and to reduce the weaknesses of steel rebars in terms of corrosion and temperature changes. In this study, GFRP bars were evaluated as a replacement of steel bars in shear walls. Diagonal tension test under unreversed cyclic quasi-static load on Reinforced Concrete (RC) panels was used. Twenty-one concrete panels with a square section, 600 mm on each side and 100 mm thick, reinforced with distinct types and reinforcement ratios were evaluated. Two types of GFRP bars with different surface coating were used: epoxy Helical wrap (GFH), and Sand coated (GFS). For comparison purposes, RC panels with steel Welded Wire Mesh (WWM) were also assessed. The minimum vertical and horizontal reinforcement required by ACI 318 (0.25%) and half of it (0.125%) were considered. The research analyzed the hysteresis curves in terms of shear stress-strain (τ-γ) and the parameters associated with shear strength, shear strain, crack width, stiffness, and toughness. Results showed that the stiffness and toughness of panels reinforced with GFH bars is similar to that of RC panels with WWM, and the toughness of panels reinforced with GFS bars is between 25% and 38% higher than those with WWM. Different models are proposed to estimate the stiffness, toughness, and crack width of the tested panels.

Performance of light weight ferrocement composite walls

The aim of this research is to examine the performance of reinforced lightweight ferrocement walls under vertical and horizontal loading. The walls were made up of two thin layers of ferrocement reinforced with one, two, three, or four layers of welded wire mesh or expanded steel mesh. The panels’ core was constructed of lightweight extruded foam. An experimental program of thirteen lightweight walls with total dimensions of 100x650x1250 mm was casted to achieve this goal and tested until failure. ABAQUS finite-element package was conducted. The parameters in this study were the kind of reinforcement; welded and expanded wire meshes, the steel bars, and. the number of layers of steel mesh. Ultimate load, mode of failure, initial cracking load, service load, energy absorption, and ductility ratio were calculated and observation to evaluate the findings. The findings displayed that the performance of the ferrocement walls reinforced with expanded wire meshes is better than that of the walls reinforced with welded wire meshes. The energy absorbed increased by 40 % for specimens reinforced with expanded wire meshes is more than that of the walls reinforced with welded wire a good agreement was observed among the theoretical and experimental observations. This paper highlights uses of employing light weight ferrocement units in building of economic housing, which is particularly valuable for both developed and developing nations, with significant frugal benefits.

Rehabilitation of post‐heated rectangular reinforced concrete columns using different strengthening configuration

AbstractIt is common knowledge that increased temperatures have a negative impact on the axial load‐capacity and stiffness of reinforced concrete (RC) rectangular columns. This is something that is commonly acknowledged. For the purpose of restoring the axial capacity and stiffness of heat‐damaged RC columns, it is absolutely essential to carefully pick a suitable method for strengthening and repairing the columns. This research paper investigates the performance of various strengthening methods, such as the use of carbon fiber‐reinforced polymer (CFRP) jackets with near‐surface mounted (NSM) steel bars and a combination of welded wire mesh (WWM) and CFRP strengthening techniques, for the rehabilitation of RC rectangular columns that have been damaged due to exposure to high temperatures. Specifically, the paper focuses on the performance of these methods in relation to the rehabilitation of RC rectangular columns. There were three groups of tested RC rectangular columns: pre‐heated and unstrengthened, post‐heated and unstrengthened, and post‐heated and strengthened. Over a period of 3 h, 600°C was applied to the heated columns. Both a scheme utilizing a combination of unidirectional CFRP strips and NSM steel bars and another utilizing a combination of unidirectional CFRP strips and WWM were evaluated. Axial compression tests were performed on each column until failure occurred. The experimental test outcomes revealed that exposure to high elevated temperatures led to a decrease in the axial load‐carrying capacity of 38.6% and a decrease of 75.9% in initial stiffness, compared to unheated RC columns. Both strengthening schemes proved effective in restoring and surpassing the initial load‐carrying capacity of undamaged RC rectangular columns by an average of 35%. Notably, the combination of CFRP strips and WWM exhibited superior performance in restoring the initial stiffness of post‐heated RC rectangular columns, representing a novel finding. The strengthening scheme employing WWM and CFRP recovered 61.3% of the lost axial strength caused by high temperature, while the NSM/CFRP scheme restored 34.5% of the lost axial strength. In addition, the utilization of NSM in combination with CFRP strips as well as utilization of the WWM and CFRP systems leads to stiffness enhancement of 52.1% and 123.7%, respectively, when compared to post‐heated and unstrengthened RC columns. However, the study's findings have clearly shown that combination of WWM and CFRP strips is efficient in enhancing the strength of heated and unheated damage RC beams.

Backbone model for predicting the shear behavior of geopolymer panels under diagonal tension tests

This study develops a novel backbone model based on a set of empirical equations to predict the shear performance of geopolymer wall panels under monotonic diagonal tension. The model describes a trilinear envelope which allows to predict the shear strengths and drifts at the diagonal cracking, peak and ultimate limit states of the geopolymer panels. A comprehensive experimental program comprising diagonal tension testing on 27 squat housing panels was considered for the model calibration, including three different concrete types and three web shear reinforcement ratios made of welded-wire mesh. Results showed that geopolymer concrete contribution to cracking and peak strengths of the panels can be set as 0.62fc′, drifts at 0.03%-0.05%, 0.20%-0.45% and 0.75%-0.85% are advised for the cracking, peak and ultimate limit states, and new efficiency factors of the web reinforcement can be fixed as 0.35–0.75 for geopolymer panels. In addition, a statistical analysis demonstrated the trustful fitting of the proposed model reaching average prediction-to-test ratios ranging from 0.8 to 1.2, average coefficients of variation of 15%, and average overpredictions close to 40%. The backbone model proposed here is intended to be a useful reference in a new preliminary performance-based framework for earthquake-resistant structural design of geopolymer concrete panels and low-rise walls controlled by shear deformations.

Experimental assessment of retrofitted damaged mortarless dry stacked interlocking masonry walls

The aim of this research study is to experimentally investigate the effectiveness of ferrocement overlay on the seismic capacity of damaged mortarless dry stacked masonry constructed with self-interlocking compressed earth blocks. For the achievement of the aim, two full scale damaged walls were retrofitted with ferrocement overlay technique. To study the effects of openings, one wall was provided with a window, while the other one was a solid wall. Retrofitting materials consist of 18-gauge galvanized steel welded wire mesh having opening size of 12.5 × 12.5 mm (0.5" × 0.5″) and 1:4 conventional cement-sand mortar. The walls were tested with displacement-controlled quasi static cyclic loading protocols. The seismic performance of the retrofitted walls under a combination of vertical axial load and lateral reverse cyclic loading was compared to the specimens before retrofitting. Damage patterns and different seismic parameters such as force deformation curve, energy dissipation, stiffness degradation and performance levels were assessed. The results show that the seismic capacity of damaged mortarless dry stacked interlocking masonry can be restored and enhanced as the overall response of the structure is significantly improved.

A study on torsional behaviour of rectangular reinforced concrete beams with U-shaped encased welded wire mesh

Concrete is one type of composite material composed of fine and coarse aggregate bonded together with cementitious paste that is durable in its hardened state over time. It has now become an important and widely used building material. However, it possesses a brittleness material property in tension even though it is strong in compression. Here the study is restricted to the concrete subjected to torsion phenomena. In the past decades, various ways have been explored to improve the ductile material strength property of the concrete matrix in proposed new construction. Reinforced concrete is constructed by using conventional reinforcements; prestressed concrete is an example of that. Also, various types of fibers in the form of discrete nature are applied to improve the tensile strength capacity of concrete in proposed construction, and retrofitting techniques using various materials are exercised to strengthen the existing structures. Hence, remarkable research in the literature on fiber reinforced concrete and on FRP techniques has been carried out. However, welded wire mesh with high yield strength can be encased in concrete members to improve composite material property and avoid abrupt cracking with an increase in torque carrying capacity of plain and reinforced concrete beam specimens used for proposed construction.

Studies on heavy duty pavements reinforced with steel fibers for port infrastructures

Steel fiber reinforced concrete (SFRC) for industrial floors has become a state-of-the-art construction method in all industries worldwide, including the construction of port platforms. The first patent that refers to a dispersed reinforced concrete element with steel fibers there exists since 1874 and was patented in the USA (California) by A. Bernard who proved the improvement of the strength of the concrete by adding some uneven steel scraps. Steel fibers have been created to improve the durability and flexibility of concrete under high loads, over long periods of time, providing three-dimensional reinforcement of concrete. Steel fibers can be used as the sole form of reinforcement or in combination with reinforcement bars or welded wire mesh.

Experimental Behavior of Confined Masonry Walls Rehabilitated with Reinforced Mortar Jacketing Subjected to Cyclic Loading

Results of an experimental program of 13 confined masonry walls rehabilitated with different techniques are presented. All specimens were built to full-scale with an aspect ratio (height to length) of 1. Vertical confining elements of one wall were built with 6.4 mm diameter welded wire reinforcing cages. Before rehabilitation, 11 of the 13 walls were initially tested to induce repairable damage; the other 2 were strengthened in an undamaged state. During testing, walls were subjected to a constant vertical load. Initially, damaged walls were rehabilitated using various techniques, such as jacketing made of mortar and welded wire mesh and synthetic or steel fibers. One initially damaged wall was rehabilitated with premixed mortar and fiberglass mesh. After rehabilitation, specimens were tested for failure. The experimental program is discussed, including materials characterization and main test results. Recommendations to practicing engineers involved in rehabilitating earthquake-damaged masonry structures are presented. It was found that the original capacity of the walls, in terms of strength, stiffness, and deformation, was increased considerably using the studied techniques. It is concluded that the techniques evaluated in this project are adequate for the seismic rehabilitation of masonry structures.

An experimental behaviour of RCC rectangular beams with U-shaped encased welded wire mesh under torsion phenomena

Concrete is one form of composite material composed of fine and coarse aggregate bonded together with cementitious paste that is durable in its hardened state over time. Although it is robust in compression, it has a brittle material property in tension. Axial and shear forces, bending moments, and torsion moments may arise in the concrete body in a reinforced concrete design depending on the loading conditions. In this sequel, the encased welded wire mesh with high yield strength is used in order to improve composite material characteristics and reduce abrupt cracking with an increase in torque carrying capacity of concrete specimens. A total of 18 beam specimens were casted and tested under pure torsion, in that six numbers were control specimens and the remaining twelve numbers were specimens with encased welded wire mesh. U-shaped wrapped WWM, both in the form of transverse strips and continuous U-shaped sheets are used to observe enhancement in the cracking and ultimate torsional strength of plain and RCC rectangular beams respectively. The curves of tested specimens containing WWM wrapping patterns showed the specimens containing WWM resist more torsional loads as compared to control specimens. The ultimate torque get increased effectively due to the introduction of U-shaped WWM wrap in fully reinforcement type means longitudinal reinforcement with closed stirrups beam specimens.

Use of steel wire mesh for compressive strength enhancement of AAC masonry wall

Autoclaved aerated concrete (AAC) is an alternate building block but possess a low compressive strength in comparison to the traditional burnt clay bricks. Past earthquakes have shown that the seismic capability of the masonry walls, particularly using low-strength blocks are very weak, and thus strengthening of this masonry is necessitated. Wire mesh is one of the most common and cost-effective strengthening materials. Wrapping the entire surface of the wall with wire mesh is the most adopted technique. However, in large-scale construction, it is un-economical. Thus, the present study investigates the behaviour of AAC masonry wall by embedding the steel wire mesh at the bed joint and bed-head joint of the masonry course. Two types of wire mesh, i.e., (a) chicken wire mesh (CWM) and (b) welded wire mesh (WWM) were employed for the strengthening. Wire mesh was alternately installed at the bed joint of the course of the masonry and subsequently installed at the bed-head joint of the course with proper anchorage using a U nail. The results show that strengthened wall specimens improve the compressive load capacity, energy dissipating capacity, ductility, and stiffness, as well as significantly improving the abrupt failure of the wall specimens. Bed-head joint strengthened specimens outperform the bed joint strengthened specimens in terms of capacities.