REVIEW ON ANALYSIS OF FERROCEMENT - CONSTRUCTION MATERIAL

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1 REVIEW ON ANALYSIS OF FERROCEMENT - CONSTRUCTION MATERIAL Shubham R. Dakhane, P.R.M.I.T & R. Bandera Akshay G. Bahale P.R.M.I.T & R. Bandera Kaustubh P. Gatlewar, P.R.M.I.T. & R. Badnera Alhad D. Raut, P.R.M.I.T & R. Bandera Abstract- Ferrocement is suitable for the construction of roofing/floor elements, precast units, manhole covers, and construction of domes, vaults, grid surface and folded plates. It can also be used for making water tanks, boats, and silos. It is concluded that the first crack and ultimate loads increase with the increases number of layer wire mesh. From the studies, it is observed that the load carrying capacities, deformation at ultimate load and energy absorption capacities are high in the case of increasing the number of wire mesh layers. Ferro- means iron although metal commonly used in ferro-cement is the iron alloy steel. Today cement usually means Portland cement, Mortar is a paste of a binder (usually Portland cement), sand and water; and concrete is a fluid mixture of Portland cement, sand, water and crushed stone aggregate which is poured into formwork (shuttering) Prefabricated elements are used In construction industry as an alternative system to overcome the formwork problems in addition to getting better quality control. The prefabricated elements made of reinforced concrete are extremely heavy and difficult to transport, placing in position and to construct. Alternatively, ferrocement panels are being used in construction industry due to its good structural performance and low cost. This paper concludes that ferrocement can be a best suitable material in upcoming years with a large no of applications. In this paper review work is presented on ferrocement as a construction material and its properties. This paper also focuses on structural behavior of ferrocement when used along with different structural members. I. INTRODUCTION Ferrocement is a type of thin wall reinforced concrete commonly constructed of hydraulic cement mortar reinforced with closely spaced layers of continuous and relatively small size wire mesh which may be made of metallic or other suitable materials. Since ferrocement possess certain unique properties, such as high tensile strength-to-weight ratio, superior cracking behavior, lightweight, mold ability to any shape and certain advantages such as utilization of only locally available materials and semi-skilled labor/workmanship, it has been considered to an attractive material and a material of good promise and potential by the construction industry, especially in developing countries. It has wide range of applications such as in the manufacture of boats, barges, prefabricated housing units, biogas structures, silos, tanks, and recently in the repair and strengthening of structures. Ferrocement is suitable for low-cost roofing, pre-cast units and man-hole covers. It is used for the construction of domes, vaults, grid surfaces and folded plates. It can be used for making water tanks, boats, and silos. Ferrocement is the best alternative to concrete and steel. Generally, ferrocement shells range from 10 mm to 60mm in thickness and the reinforcement consists of layers of steel mesh usually with steel reinforcing bars sandwiched midway between. The resulting shell or panel of mesh is impregnated with an extraordinarily rich (high ratio of cement to sand) Portland cement mortar. Ferrocement is a highly versatile construction material and possess high performance characteristic, especially in cracking, strength, ductility, and impact resistance ISSN: Page 88

2 II. LITEURATURE SURVEY: Although other forms of ferrocement may have existed earlier, credit for using it should go to Joseph Louis Lamboat in France, who constructed a rowing boat from a net of wires and thin bars, and filled with cement mortar. Lamboat applied for patent in year 1855 for his invention with name Ferciment Sharma et.al (2013) reported ferrocement covers all dimension of sustainability and also durable material. It has better crack arrest mechanism and efficient autogenesis healing of micro cracks, fire resistant, damage being negligible and easily repairable. Ferrocement can be used in various applications such as housing application rural application such as water tank, grain silos, canal lining, and some special applications as precast sandwich wall, ferrocement water filters, ferrocement segmental shells etc. Kute et.al (2013) studied the effect of orientation of wire mesh on ferrocement. The conclusion arises from the study that compressive strength of ferrocement increases with increase in total volume fraction of reinforcement (%) and specific surface of reinforcement (mm2/mm3) for horizontal and vertical orientation of hexagonal mesh; the orientation of reinforcement i.e. transverse to axis of loading offers more compressive strength than that of vertical orientation i.e. parallel to axis of loading. LWire Mesh: Galvanized chicken wire mesh with a hexagonal opening of size 12mm and a wire thickness of 1.29mm is generally used. Water: III. MATERIALS: The following materials are used in this work: Ordinary Portland cement Fine aggregate Chicken meshes-hexagonal opening Weld meshes-rectangular grid opening Steel according to the design Potable drinking water was used for mixing and as well as for curing Other constituent elements are as follows: Skeletal steel Reinforcing Mesh Mortar Mix Admixtures Coating Cement: Ordinary Portland cement- Some of the properties of the cement are: Specific gravity = 3.15, Standard consistency = 34%, Initial setting time = 40mins Compressive strength = N/mm Fine Aggregate: Fine aggregate used are passing through 4.75 mm IS sieve with a specific gravity of 2.62 ISSN: Page 89

3 IV. APPLICATIONS OF FERROCEMENT: A. FERROCEMENT WATER TANKS: Ferrocement Water Storage Tanks are constructed using ferrocement plates of 25 mm 30 mm thick. The structures are as strong as steel plates and are completely waterproof. Moreover, these types of tanks are highly resistant against earthquake & wind and are have high durability. Following are some of the features of these tanks: RCC Sturdy construct Weight of the tower less by about 50% of Life time Durability Economical B. FERROCEMENT WATERPROOFING: Waterproofing to R.C.C. structure is carried out with modern material known as Ferrocement. It is carried out generally in two layers of about 8 mm thickness each layer. It consists of iron mesh reinforced cement matrix layers which are vibrated in situ. The top surface also vibrated finished smooth with non-metallic fibers impregnation. The cement matrix and wire mesh layers are laid alternately. Each cement matrix layer is laid on a bond coat for assured integrity. Each wire mesh layer is fixed with u-clips to the base. The performance of the treatment is most excellent. Because in situ low water cement ratio cement matrix is vibrated and become dense with nil/negligible pores. The wire mesh layers generally two nos. prevent crack formation, if at all due to shrinkage, temperature or structural relative movements. Therefore the treatment is durable and permanent. It takes ware and tare efficiently due to certain admixtures. The wire mesh layers add strength to the main structure in addition to crack formation prevention. It is laid on insulated foundation layer of about average thickness of 40 mm. There will be dead load reduction to conventional brickbat coba treatment. It adds strength to base structure. The waterproofing of the tank from inside saved the same from getting demolished. C. STREMGTHENING OF REINFORCED CONCRETE ELEMENTS: Ferrocement is used for strengthening reinforced concrete columns for different types of deficiencies. Tested columns have been jacketed with ferrocement layers, in order to provide extra confinement to the section. The typical thickness of ferrocement varies between cm. Overlapping of the wire mesh is generally provided to avoid opening of the mesh reinforcement. Afterwards, the wire mesh is plastered with mortar and cured before testing. The mechanism used to increase in axial capacity of columns is to provide better confinement to the existing element. Studies by Mourad et al., Kaish et al., Kaish et al., Kondraivendhan et al. and Xiong et al., Figure have indicated that this material can successfully increase strength, stiffness, ductility and cracking behaviour of deficient columns. Ferrocement works as an external confinement element, thus restraining the column from lateral expansion, increasing the axial capacity and providing a more uniform stress distribution across the section. The failure mode is ductile as opposed to the brittle failure of concrete columns. The effect of varying different parameters of ferrocement jacketing has been investigated. For instance, Kondraivendhan et al. investigated the effect of concrete grade; Kaish et al. and Kaish et al. investigated the number, type and orientation of mesh layers. The results indicate that ferrocement can increase the capacity of all existing element, with no regards on the grade of concrete. ISSN: Page 90

4 4. Saving in overall cost compared to R.C. system. E. EFFECT OF WIRE MESH ORIENTATION ON FERROCEMENT ELEMENT - By Dr. S.K. Kaushik Professor and Head, Department of Civil Engineering, Indian Institute of Technology, Roorkee- D. DESIGN OF COLLEGE BUILDING WITH FERROCEMENT ELEMENTS By Arun Purandare, Structural Consultant, Pune A system of precasting with ferrocement elements was developed. Three elements namely column boxes, channel beams, and a deck slab were used for the entire section. The aim was to crate light weight elements for lifting, eliminate formwork totally and reduce member propping during construction to an absolute minimum. All the three aims have been fulfilled. An engineering college building was under construction for D.Y. Patil Engineering college at Ambi village, Talegaon. The G+4 structure has been constructed by the conventional method of in situ R.C. construction. The column spacing are 7m X 7.5 m. Each floor is about 3000 sq.m. built up area. The foundation and columns were designed for G+8 upper floor building. At this stage of construction it was decided to add the balance 4 floors with member element made with Ferrocement. The structural frame had to be the same as that used on lower floor. The principal idea was to eliminate formwork and the slab and beam units shall be able to carry all dead loads. The slab and beam had to span between supports without propping. The members therefore eliminated formwork and propping at site. The design of members was also done with ease of construction and lifting to its position as primary consideration. Slab elements span between channel beams. The panels are 3m X 1m wide. The design of panels is done as suggested by ACI. The project has been saving in material cost and significant saving in time. The main advantages seen in the system are:- 1. No formwork and minimal scaffolding. 2. Elements casted on ground at site or yard 3. Very fast erection and reduction in time of construction. The experiment investigated the efficiency of mesh overlaps of ferrocement elements by varying the length of overlap in square woven meshes with different wire diameter and mesh openings. The number of mesh layers has also been varied and tested under flexure. Cement-sand mortar mixes of 1: 1.5 and 1:2 were used for the above investigations. They developed an analytical expression for the lap length (Lp) based on the concept that the mesh overlap must be sufficient to develop full bond strength around the surface w that there is no slippage while taking the stress allowed to it. They cast 350 test specimens having 400x200 mm dimensions, with 5 mm cover on all the four sides, with w/c-0.4. All the specimens were tested under central point loading on a simply supported span of 300 mm. Based on the above, they concluded that (i) the mortar strength, diameter of reinforcing wire and mesh opening influence the overlap length; (ii) bond failure occurs due to slippage at overlap. when length of mesh overlap is insufficient, with the cracking load much lower than that of a continuous mesh reinforcement; (iii) a minimum overlap of 100 mm to be provided. F. FERROCEMENT BUILDING By Dr. B. N. Divekar, President ferrocement society India. Ferrocement elements like floors, roofs and walls for residential places and office buildings are fabricated using ferrocement columns, a beam & panel system that helps reduction in consumption of cement and steel. Furthermore, these require almost no shuttering cost and have longer functioning life. The weight of a ferrocement building is 50% less than that of a RCC building. ISSN: Page 91

5 G. HORIZONTAL AND VERTICAL EXTENSION OF RCC BUILDING It is most usual that extensions to the buildings are required to be carried out in view of necessity of more area requirement in the building. The limit of additional floors depends upon the strength of columns mainly. Sometimes columns are erected very near to the building and additional floors are provided. Horizontal extension of existing building adds to floor area at the same level which is required many times rather than one above the other. Normally this is provided by constructing columns near the existing columns and also farther as required and floor provided. Horizontal extension of about 1.2m (1 in) thick ferrocement with internal ribs (Jennings, 1983). I. FLEXURAL BEHAVIOUR OF FERROCEMENT Alrifaie tested ferrocement slabs (500x500 mrn) in which three different arrangements. a) all oriented in one direction: b) a l m oriented in orthogonal direction and c) twin layers-each twin layer consisting of two orthogonally oriented meshes in contact with each other were investigated. A total of I2 square slabs (20 mm and 30 mm thick) were tested under uniform load. Based on the above studies die) concluded that the arrangement consisting of twin layers with two meshes orthogonal and placed in contact is superior to the other two arrangements consisting of all the meshes uni directionally - oriented or Alternate layers equally spaced with orthogonally oriented meshes. The increase in first cracking load is 16% to 24% for 20 mm and 30 mm thick slabs (i.e.,) models. The above increase is 13.2% and 11.75% in the ultimate load value for the 20 mm and 30 mm thick models respectively. Hence, they recommended that for the slabs under bi-axial state of bending the meshes should be arranged in twin layers. which has to be cantilever, is not feasible with RCC and cannot be thought of in view of anchorage problem, high moments of cantilever beams and slabs and beam with wall load at the edge of extension. This` problem can be solved by the use of ferrocement. H. ROOFING APPLICATIONS: Ferrocement appears to be an economic alternative material for roofing; and flat or corrugated roofing system is quite popular (ACI Committee 549- R97). Ferrocement roofing materials can be factory mass-produced in prefabricated form, a process best suited to the concentrated demands of the urban area, or it also can be fabricated in-situ in villages. Construction of hundreds of ferrocement roofs for poorer areas of Mexico has been well documented; most of these ferrocement roofs were dome shaped with a span of 3 to 6m (10 to 20 ft); and large ferrocement roofs have also been constructed in Italy spanning 17m (56 ft) with a thickness of 30 mm (1.2 in.). The use of ferrocement as roofing for large span structures with internal ribs has been successful in many European and South American countries. Domes have been constructed in Jordan using 25 mm J. SHEAR BEHAVIOUR OF FERROCEMENT- By Prof (Dr). S.K Patra, Professor, Department of Civil Engineering, KIIT University, Bhubaneswar, Odisha From the experiment on ferrocement for the shear behavior Dr. Patra concluded that(a) Shear behaviour of ferrocement element is equal to that of reinforced concrete element.(b) The partial safety factor can probably used for designing the ferrocement element against shear. (c) The critical shear force is normally found to be governed by flexure-shear. (d) After experimental as well as empirical Solution the shear strength of ferrocement depends upon the volumetric fraction of wire mesh and the shear span to depth ratio. (e) The ductility and load carrying capacity of ferrocement element can be improved by applying different layer of wire mesh. The number of mesh increases the shear load carrying capacity of the ferrocement element. V. ADVANTAGES OF FERROCEMENT OVER RCC: 1. Bond force on small section reinforcement is very high 2. Resulting in delayed bond failure with delayed failure of flexures, shear &torsion 3. Delayed crack formation till reaching near to yield ISSN: Page 92

6 4. High permissible strength quite near to yield 5. No collapse during earthquake duration of which hardly few seconds 6. Only deformation that too may be at Richter scale 8 or so. 7. Ferrocement structures remained Untouched during Earthquake at Richter scale High degree of durability 9. High degree of ductility 10. It requires less strength development to carry its own low weight 11. R.C.C. requires more strength to carry its own heavy self-weight 12. Ferrocement is a low self wt. construction, reduction being about 50% that of RCC [10] Pushyamitra Divekar (2011), Use of Ferrocement in Construction Industry, Proceedings of the National Conference on Ferrocement, FS 2011, May, 2011, Pune, India, pp [11] Kondraivendhan B, Pradhan B. Effect of ferrocement confinement on behavior of concrete. Construction and Building Materials, 2009; 23: VI. CONCLUSION: The prefabricated houses made of ferrocement have a good seismic behavior. Houses in ferrocement can easily sustain in earthquake up to scale Technique can be used for watertight structures and retrofitting of water structures The ferrocement layers will substitute as shear reinforcement in the joint region. Hence the use of ferrocement layers in strengthening joints without shear reinforcement will enhance the behavior of these joints and will reduce the vulnerability of these joints to be excessively damaged when subjected to seismic loading. Ferrocement construction is an exciting alternative to conventional wooden and masonry methods. Ferrocement is an innovative material and the ready availability of materials and ease of construction make it suitable in developing countries for housing, and water and food storage structures. VII. REFFERENCES: [1] Shetty M.S. Conrete Technology Theory and Practice S Chand and Company publication,ramnag, New Delhi,2012. [2] Gambhir M.L., Conrete Technology Theory and Practice Tata Mcgraw Hill Publication, New Delhi. [3] Divekar B. N. (2013), Industrialized Housing with Ferrocement, National journal of Ferrocement, Page number [4] Using Ferrocement in Repair and Strengthening of Corner Beam-Column Joints subjected to Displacement Cyclic Loading Ashraf El-Abd1*, Ibrahim Shabaan2, Osama A. Seoud3 [5] Hysteric model and seismic vulnerability of ferrocement housesdaniel BedoyaRuiz program of Civil Engineering University of Medellin, Colombia, abedoya@udem.edu.co.in [6] Hassan M.H. Ibrahim 2011 Shear capacity of ferrocement plates in flexure. [7] ACI committee 549 report, Guide for design, construction and repair on ferrocement.aci 549.1R-93,1993 [8] Divekar, B.N. (2011b) All-in-One A Unique Method of Construction, Proceedings of the National Conference on Ferrocement, FS 2011, May 2011, Pune, India, pp [9] Divekar, B.N. (2011a) Revolutionary Ideas and Innovative Structures in Ferrocement, Proceedings of the National Conference on Ferrocement, FS 2011, May 2011, Pune, India, pp ISSN: Page 93