Ferrocement Laminates Research Articles

Retracted: Flexural Behaviour of Chicken Mesh Ferrocement Laminates with Partial Replacement of Fine Aggregate by Steel Slag

Retracted: Flexural Behaviour of Chicken Mesh Ferrocement Laminates with Partial Replacement of Fine Aggregate by Steel Slag

Experimental response of HPFL-BSP strengthened RC sub-assemblages subject to corner column removal

Few existing buildings have been constructed in accordance with progressive collapse codes, resulting in poor progressive collapse behavior. Previous studies indicated that reinforced concrete (RC) structures with one lost corner column are more susceptible to progressive collapse than structures that lose a middle or edge column. To mitigate the likelihood of progressive collapse of RC structures subjected to corner column loss, we adopted a novel strengthening scheme (high-performance ferrocement laminate and bonded steel plates) to improve the progressive collapse behavior. Three one-third-scale RC sub-assemblages were constructed and tested to investigate the effectiveness of this strengthening method: control sub-assemblage, beam-strengthened sub-assemblage, and slab-strengthened sub-assemblage. The results demonstrate that beam and slab strengthening schemes can improve the static load-carrying capacity, dynamic resistance, energy dissipation, and ductility of the sub-assemblage. Moreover, the slab-strengthening scheme altered the failure modes of the beams and slabs, significantly increasing the ductility of the sub-assemblage. Consequently, the slab-strengthening scheme exhibited superior performance to the beam-strengthening scheme. Based on the energy conservation theory, the ultimate point of the sub-assemblages with a lost corner column was redefined. Furthermore, theoretical models were proposed and validated to predict the yield, peak, and ultimate loads.

Repairing of web opened RC beam with ferrocement laminates using alkali activated mortar

Repairing of web opened RC beam with ferrocement laminates using alkali activated mortar

Enhancing the behavior of reinforced concrete box girders under Two-point Loading: Numerical and experimental investigations

Reinforced Concrete Box Girders: RCBGs are considered in concrete bridges as significant members and they have been closely accepted as bridge systems due to their structural efficiency: economical construction, serviceability, high stability and aesthetic requirements. The aim of the current research is determining the best way to enhance the behavior of RCBGs, which includes the outcomes of practical and numerical programs of 15 samples tested under bending. The use of ferrocement laminate on the tensile side or in the form of a U-shape, the number of meshes, as well as their type (welded or expanded), and the use of composite materials: Carbon Fiber Reinforced Polymer and Glass Fiber Reinforced Polymer (CFRP and GFRP) were all considered. For composite materials, the strengthening was applied at the tensile side only and wrapping the composite material around the web like a U-shape along the total beam’s length or as strips with different sizes and spacing. The results indicated that wrapping GFRP and CFRP sheets like a U-shape along the total beam’s length gave the same ultimate loads and it represents the highest load of the tested beams. It increased by ∼ 78 % than the control beam. The numerical model gave good results in comparison with the test results. The difference between them does not increase ∼ 13 %.

Seismic Upgradation of RC Beams Strengthened with Externally Bonded Spent Catalyst Based Ferrocement Laminates

Globally, since there are more systems of civil infrastructure, there are also more degraded buildings and structures. If upgrading or strengthening is a practical option, complete replacement is likely to be an escalating financial burden and may be a waste of natural resources. It is necessary to repair or strengthen a number of reinforced concrete buildings and structures in order to boost their load-bearing capabilities or improve their ductility under seismic stress. Additionally, due to changes in service circumstances, a structure might need to be modified to reduce deflections or manage cracking. Strengthening may be preferable to limiting usage, capping applied loads, and regularly inspecting the structure rather than removing the existing structure or part and building a new one. This study aims to examine the flexural, shear, and combined effect of flexural and shear behavior of reinforced concrete (RC) beams strengthened with externally bonded spent catalyst-based ferrocement laminates and compare them to the control beams (unstrengthened) under two-point loading conditions. This study involves researching laminates with various spent catalyst doses, such as 3, 6, 9, and 12%, in an effort to determine the best amounts that will improve the structural performance of ferrocement laminates. Twelve spent catalyst-based ferrocement laminates measuring 500(L) × 125(B) × 20 mm (thickness) with 3% volume fraction of meshes each were cast and tested in the lab as part of the preliminary investigation. For repeatability, three laminates per case were employed. Eight numbers of under-reinforced RC beams measuring 75(L) × 100(B) × 150(D) mm were cast for the main study; six numbers were strengthened with optimized spent catalyst-based ferrocement laminates bonded with flexible epoxy systems at the tension zone, shear zone, and combination of tension and shear zone. Two of the beams were cast as control specimens. The beams were then evaluated using a Universal Testing Machine (UTM) with a 1000 kN capacity under two-point loading conditions. As a result, the strength, yield load, ultimate load, stiffness, ductility, and related failure modes of all tested beams' flexural and shear performances were examined. According to a preliminary analysis of laminates made of spent catalyst, the dosage of 9% provides good flexural strength in comparison to other doses. In comparison to the strengthened beam, the control beam's initial cracks appeared earlier. In comparison to the control beam, the strengthened beam has an increase in load-carrying capacity of 18% for flexure, 16% for shear, and 30% for the combined impact of flexure and shear. In comparison to the control beam, the deflection of the strengthened beam was decreased by close to 20 to 40% for flexure, 10 to 30% for shear, and 15 to 20% for the combined effects of flexure and shear at the same load level. In relation to control beams, the ductility also improved up to 30% for flexure, 25% for shear, and 25% for the combined impact of flexure and shear. Similar to this, the retrofitted beam is stiffer than the control beam by approximately 40% for flexure, 48% for shear, and 30% for the combined effect of flexure and shear. Theoretical formulation by section analysis is also derived and it gives close agreement with control and strengthened beams. The flexural and shear strengthening of the RC beam retrofitting system is effectively increased by using spent catalyst-based ferrocement laminates. No beam showed signs of premature and brittle failure. According to the test findings, it can be said that spent catalyst-based ferrocement reinforced beams perform better in every way than control beams. Doi: 10.28991/HIJ-2023-04-01-013 Full Text: PDF

Experimental Investigation on Flexural Behaviour of Ferrocement Laminates Using Different Forms of Meshes

Abstract: The present study describes the results of testing ferrocement panels reinforced with of different types of meshes. The main objective of the study was to investigate the effect of different types of meshes as reinforcement in thin mortar specimen and select the best suitable mesh for further work. Types of meshes were used expanded metal mesh, galvanized woven mesh and welded mesh has a diameter of 1.58 mm. Size of openings are 20x35 mm, 10x10 mm and 15x15 mm. Panels of a size of 560x150x35 mm were reinforced with three layers of wire mesh. Panels were casted with mortar of mix proportion 1:2 and water cement ratio 0.40. The four specimens were tested under four-point loading system on universal testing machine after curing period of 7 days and eight specimens after curing period of 28 days. Test results shows that the flexural strength of the specimen with welded mesh exhibits greater flexural strength than other two types of meshes.

Study on Flexural Behaviour of Ferrocement Composites Reinforced with Polypropylene Warp Knitted Fabric.

Ferrocement is a cost-effective construction material used in the low-cost constructions. It is produced with the combination of cement mortar with closely spaced wire mesh known as chicken wire mesh. Ferrocement process eliminates coarse aggregates when compared to reinforced concrete thus makes the process simple. This paper deals with the influence of various characteristics of warp knitted fabric on the flexural properties of ferrocement composites. Ferrocement composites have a wide range of applications in the construction industry and it has some limitations due to the durability issues. Among the various durability issues, corrosion is one of the main issues to be addressed to enhance the long-term service life of the ferrocement composites. The idea of using non-metallic mesh to eliminate the corrosion problem is discussed in this paper. In this experiment, warp knitted fabric reinforced ferrocement composites were produced using polypropylene warp knitted fabrics. This paper deals with the flexural properties of ferrocement composites made of warp knitted fabric coated with expoxy. This paper deals with the flexural properties of ferrocement composites made of warp knitted fabric coated with expoxy. These composites were analyzed for their flexural strength, energy absorption and ductile property. The variables in the experiment are filament thickness, warp knitted structure and number of layers in the composites. Experimental results proved that the replacement of chicken mesh wire by warp knitted fabrics has an impact in the flexural properties of the composites and the effect of variables in the experiment set up has been analyzed. There is an imporvement of 200% is observed in the first crack load and 120% improvement in the ultimate load of the warp knit fabric reinforced composite compared to control sample. Experimental results proved that there is an increase in flexural strength of ferrocement composites made up with warp knitted fabrics. Microstructure studies like SEM and EDX on ferrocement laminates confirmed good bonding between the mortar mix and warp knitted fabrics.

Seismic Behavior of Strengthened RC Columns under Combined Loadings

Twenty-five reinforced concrete (RC) columns of section size 250 × 250 mm were designed and tested to study the seismic response considering the effect of loading case, strengthening method, and the predamage level, containing 21 columns reinforced with high-performance ferrocement laminate (HPFL)-bonded steel plates (BSPs), i.e., the intact strengthened columns (ISCs), earthquake-damaged strengthened columns (EDSCs), corrosion-damaged strengthened columns (CSCs) and coupled-predamaged strengthened columns (CPSCs). The bearing capacity of the specimens under the four different types of loading methods is ranked as follows: uniaxial compression–bending–shear (CBS) members, biaxial CBS members, biaxial CBS-torsion (CBST) members, and uniaxial CBST members. Compared with nonstrengthened specimens, the cracks of the strengthened RC columns are more fully developed, and the failure modes have been changed after strengthening. The failure modes and load–deformation curves had little significant difference for the strengthened RC columns with different damage under combined loading levels. The bearing capacity of strengthened RC columns with the applied loading of 400 kN improved, which increased to 60.1%–114.7%, 29.9%–103%, 65.2%–127%, and 49.2%–104.5% for ISCs, EDSCs, CSCs, and CPSCs, respectively. Moreover, the bearing capacity of specimens decreased due to the existence of horizontal eccentricity. Finally, based on the degraded trilinear restoring force model, the strengthened influence coefficient for loading α and displacement β and the torsion influence coefficient for loading γ and displacement ξ were introduced. A modified restoring force model of RC columns was presented, reflecting the loading method, predamage level, and strengthening method. The theoretical calculation values align with the test load–deformation curves, and the mean absolute error is almost less than 15%.

In-plane shear behavior of masonry panels strengthened with ultra-high ductile concrete (UHDC)

Ultra-high ductile concrete (UHDC), a new type of modified fiber reinforced concrete, exhibits superior strain-hardening and multi-cracking behaviors under tensile load. In order to study the effectiveness of UHDC layer strengthening on non-reinforced masonry structures, one un-strengthened panel as reference, one panel strengthened with high performance ferrocement laminate layer and six panels strengthened with UHDC layers by single side or double sides were tested under cyclic diagonal compression. The shear capacity, hysteresis behaviors, stiffness, and pseudo-ductility of all the panels were characterized and presented in this article. UHDC layer strengthening changed brittle failure mode of masonry panels into a much more ductile mode. The in-plane shear strength of the single- and double-side strengthened panels were 1.8 ∼ 2.4 and 4.2 ∼ 5.7 times higher than that of the un-strengthened one, respectively. The ductility, stiffness and energy dissipation of the masonry panels were obviously enhanced by UHDC layer strengthening. Additionally, the prediction based on the modified ACI 549 and JSCE 2008 algorithms agreed well with the experimental results. The present study demonstrated that applying UHDC layers, either on one or two faces to un-reinforced masonry wall, can significantly improve its seismic performance.

Progressive collapse resistance of multistory RC frame strengthened with HPFL-BSP

The field of progressive collapse has attracted considerable attention worldwide, while little existing building structure has been constructed with progressive collapse design. Therefore, some researchers began to explore effective strengthening methods to improve the progressive collapse resistance of existing building structures while saving cost, resources, and time. In this paper, two 1-bay-by-2-bay two-story reinforced concrete (RC) frames with the loss of one edge column were constructed and tested, including the control and strengthened specimens. The strengthened specimen was strengthened with high-performance ferrocement laminate and bonded steel plates to investigate the strengthening effectiveness. Based on the data collected during the experiment and simulated results, crack development patterns, load-displacement relations, lateral deformation , load distribution, and the effect of strengthening were discussed. Additionally, the finite-element (FE) simulation and the theoretical analysis for such structure were implemented. The results show that the initial stiffness and bearing capacity of frame increased after strengthening. Increasing the steel strand quantity, the peak load can be significantly increased. The stiffness in different floor will have an effect on the load bearing distribution. Higher stiffness in floor will bear much vertical load. The axial compression on adjacent columns increased while decreased in the diagonal columns. The contribution to bearing capacity of slab is weaker than beams. The slab could share about 2/3 vertical load of beams for control specimens and less than 1/2 vertical load of beams for strengthening specimens.

Retracted] Flexural Behaviour of Chicken Mesh Ferrocement Laminates with Partial Replacement of Fine Aggregate by Steel Slag

Bending tests were conducted on ferrocement laminates containing chicken mesh and steel slag. The fundamental goal of the examination was to investigate the effects of partial substitution of fine aggregate by steel slag in cement mortar combining chicken mesh of different volume fractions as reinforcement in thin ferrocement laminates. The following variables were investigated: (a) volume fraction of chicken mesh as 0.94%, 1.88%, 2.82%, and 3.77% and (b) level of steel slag substitution from 0% to 50% by weight fine aggregate. Results show that ferrocement laminates with chicken mesh of volume fractions of 3.77% and 30% substitution of fine aggregate with steel slag display better performance in terms of load deflection behaviour, first crack load, ultimate load, energy absorption, and ductility ratio when related with other specimens. An analytical model has been proposed to predict the ultimate moment carrying capacity of ferrocement laminates under flexure to validate the experimental results.

Structural behavior of concrete walls reinforced with ferrocement laminates

The present work focuses on experimental and numerical performance of the ferrocement RC walls reinforced with welded steel mesh, expanded steel mesh, fiber glass mesh and tensar mesh individually. The experimental program comprised twelve RC walls having the dimensions of 450 mmx100 mmx1000 mm under concentric compression loadings. The studied variables are the type of reinforcing materials, the number of mesh layers and volume fraction of reinforcement. The main aim is to assess the influence of engaging the new inventive materials in reinforcing the composite RC walls. Non-linear finite element analysis; (NLFEA) was carried out to simulate the behavior of the composite walls employing ANSYS-10.0 Software. Parametric study is also demonstrated to check out the variables that can mainly influence the mechanical behavior of the model such as the change of wall dimensions. The obtained numerical results indicated the acceptable accuracy of FE simulations in the estimation of experimental values. In addition, the strength gained of specimens reinforced with welded steel mesh was higher by amount 40% compared with those reinforced with expanded steel mesh. Ferrocement specimens tested under axial compression loadings exhibit superior ultimate loads and energy absorbing capacity compared to the conventional reinforced concrete one.

Experimental study of predamaged columns strengthened by HPFL and BSP under combined load cases

After the ground motion, a large number of columns remain intact and can be retrofitted and reused. In this paper, to explore the effects of the loading scenario, predamage level and strengthening measures on the seismic performance of reinforced concrete (RC) columns, seven predamaged specimens strengthened with high-performance ferrocement laminate (HPFL) and bond steel plate (BSP) were tested. The results show that the bearing capacity, ductility, single-cycle energy dissipation and stiffness of all the predamaged specimens can be effectively restored and improved by this strengthening method for different loading cases. This strengthening method also significantly improves the shear capacity and changes the failure modes of the predamaged strengthened specimens from those of the corresponding predamaged unstrengthened specimens. The vertical eccentricity only slightly affects the seismic behavior of the specimens, while the horizontal eccentricity significantly increases the length of the failure region and reduces the seismic behavior of the specimens, considering the bearing capacity, energy dissipation capacity, and stiffness. The effects of different predamage levels are unique.

Experimental Investigation on Rehabilitation of Corroded RC Columns with BSP and HPFL under Combined Loadings

AbstractThis research focuses on evaluating the seismic properties of corrosion-damaged RC columns strengthened by bonded steel plate (BSP) and high-performance ferrocement laminate (HPFL). The mec...

Experimental investigation on different high rich cement mortar for ferrocement application

Abstract Nowadays the Laboratory research became assumed to enlarge high rich cementitious matrices for casting thin ferrocement laminates perfectly fitted for structural restore retrofit. The developed high rich mortar matrices contain diverse combos of silica fume and Metakaolin, and offer a great balance among flowability and rich. The matrices evolved have a 28-days compressive rich variety from 48 to 64 MPa with an equivalent float range from 129% to 138%. The different high rich mortar turned into used in generating ferrocement jackets for cylindrical stubs look at its performance of the stubs are subjected to axial stresses. The progressive excessive rich ferrocement laminates seem to provide the considerable increase and increasing in the load carrying potential, lateral and ductility. In positions of ferrocement efficiency, the stubs enveloped with the laminates containing 2 and 4 layers of welded wire meshes (WWM), presented approximately 61% and 31% increase in axial stress respectively, with a corresponding increase in axial stress of about 33% and 71% respectively. Based on the outcomes of the present research, high rich ferrocement laminates containing a particular variety of welded wire meshes may be taken into consideration as a promising material for maintenance and recovery of concrete structures, particularly when using flowable high rich mortar with WWM complying with ferrocement specifications.

Seismic performance of predamaged RC columns strengthened with HPFL and BSP under combined loadings

This paper presents an experimental investigation of the seismic behavior of coupling predamaged reinforced concrete (RC) columns strengthened with high-performance ferrocement laminate (HPFL) and bond steel plate (BSP) that are subjected to combined loadings. A total of four specimens were fabricated. After they were predamaged with corrosion and an earthquake environment, they were strengthened with HPFL and BSP, and then tested under four different combined loadings, separately, which are unidirectional compression, bending, and shear (CBS); bidirectional CBS; unidirectional compression, bending, shear, and torsion (CBST); and bidirectional CBST. Their seismic behavior, including failure mode, bearing capacity, ductility, energy dissipation, stiffness degradation, damage index and residual displacement, was analyzed. The results revealed that the coupling predamaged RC columns still had retrofit value and that the retrofitting method utilized in this paper was effective. After repairing with HPFL and BSP, the bearing capacity can be significantly improved especially for torsional specimens, which increased by more than 100%. Other seismic behavior like ductility coefficient, stiffness, and single cyclic energy dissipation can be recovered well. In addition, the horizontal eccentricity had a negative effect on the seismic behavior of specimens, while the negative effect was reduced after strengthening.

Study of Flexural Behaviour of Warp Knitted Reinforced Ferrocement Composites

This paper presents the effect of warp knit textile reinforcement in ferrocement laminates. In general, steel wire mesh is used as ferrocement reinforcement, which is often known as chicken mesh. The need for the replacement of steel mesh is the problem of corrosion, which reduces the durability of ferrocement laminate. High performance synthetic fibres and fabrics are constantly used in various research works as reinforcement in concrete. In this paper, an attempt was made to incorporate three different nylon warp knit mesh structures in the place of chicken mesh. Ferrocement composites were produced with chicken mesh and nylon warp knit fabrics. The flexural properties of ferrocement laminates were analysed in terms of the first crack load, ultimate load, energy absorption capacity and ductility factor. Nylon square mesh with 3 layers in the reinforcement has a 2.5 kN first crack load and 3.36 kN ultimate load, which is higher than chicken mesh reinforcement in ferrocement laminate. The results show that there is an improvement in the flexural properties of ferrocement laminates reinforced with a nylon warp knit structure. The flexural parameters have a direct relationship with the number of layers used in the reinforcement.

Seismic behavior of strengthened square reinforced concrete columns under combined loadings

This paper presents an experimental study examining the seismic behavior of square reinforced concrete (RC) columns subjected to combined loadings. In this study, nine full-scale square RC columns were made with the same structural properties. Five of them were strengthened with high-performance ferrocement laminate and bonded steel plates in order to investigate the effects of strengthening on the seismic behavior of RC columns under combined loadings. Finally, the failure mode, hysteretic load-displacement response, bearing capacity, energy dissipation, ductility and plastic hinge characteristics were recorded and analyzed. The results show that combined loadings reduced the bearing capacity and changed the failure modes and deformation characteristics. Strengthened RC columns had significantly improved bearing capacity and different failure modes under the same combined loadings in contrast to the non-strengthened RC columns. The vertical eccentricity had little effect on the mechanical properties of columns, while the horizontal eccentricity significantly weakened the mechanical properties of columns. The mechanical properties of uniaxial compression-bending-shear-torsion columns were the worst. The tri-linear model calculation parameters under different failure modes and combined loadings were fixed and validated by experimental results.

Repairing Reinforced Concrete Beams with Openings by Ferrocement Laminates

Repairing Reinforced Concrete Beams with Openings by Ferrocement Laminates

RC Beams Retrofitted by Ferrocement Laminates with Addition of Alccofine

RC Beams Retrofitted by Ferrocement Laminates with Addition of Alccofine