INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND TECHNOLOGY (IJCIET)

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1 INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND TECHNOLOGY (IJCIET) International Journal of Civil Engineering and Technology (IJCIET), ISSN (Print), ISSN 97 31(Online) Volume, Issue 3, May - June (13), IAEME ISSN (Print) ISSN 97 31(Online) Volume, Issue 3, May - June (13), pp. 57- IAEME: Journal Impact Factor (13): (Calculated by GISI) IJCIET IAEME COMPOSITE ACTION OF FERROCEMENT SLABS UNDER STATIC AND CYCLIC LOADING Dr. T.Ch.Madhavi *, Shanmukha Kavya.V **, Siddhartha Das **, Sri Prashanth.V **, Vetrivel.V ** *Prof & HOD, Civil Engg, SRM University, Ramapuram Chennai- 89, India. **BE (Final Year), SRM University, Ramapuram, Chennai- 89, India. ABSTRACT Ferrocement is a composite material that can be used for construction of certain structures such as ships, water tanks, boats and other similar structures, where we need not use lot of resources such as coarse aggregates. This paper presents the flexure studies on ferro cement slabs, where the number of reinforcing weld mesh layers are varied as layers, 3 layers and layers. slabs are cast, each for each type of reinforcing, i.e., slabs of layers, slabs of 3 layers, slabs of layers, using custom made moulds. They are tested for static and cyclic loading conditions of flexure testing after 8 days of curing. After the tests, the results are tabulated and represented graphically and analysed. It is found that, increasing the number of layers of mesh increases the flexural strength of the ferro cement slabs. Also, as the number of layers increase, the crack propagation is slow. Key Words: Ferro Cement Slabs, flexure, Static loading, cyclic loading INTRODUCTION Ferro cement is a composite material made up of cement mortar and reinforcement in the form of layer of mesh. Ferro cement consists of closely spaced, multiple layers of mesh or fine rods completely embedded in cement mortar. A composite material is formed that behaves differently from conventional reinforced concrete in strength, deformation, and potential applications, and thus is classified as a separate and distinct material. It can be formed into thin panels or sections with only a thin mortar cover over the outermost layers of reinforcement. Compared to other cement concrete structures, those made of ferrocement are light weight, tough, durable, crack resistance and can be made into virtually any shape 1. Over 57

2 International Journal of Civil Engineering and Technology (IJCIET), ISSN (Print), ISSN 97 31(Online) Volume, Issue 3, May - June (13), IAEME the years, applications involving ferrocement have increased due to its properties such as strength, toughness, water tightness, lightness, ductility and environmental stability. Ferrocement may be cast in various shapes and forms even without the use of form work and are aesthetically very appealing. Ferrocement has a very high tensile strength to weight ratio and superior cracking behaviour in comparison to reinforced concrete. Hence, Ferrocement is an attractive material for construction of shell, folded plate, ribbed slab and housing components. The slenderness of these elements may adversely affect their performance under working loads. Hence, there is a need to study their (a) first crack strength and (b) loaddeflection (P-d) behaviour. While (a) and (b) characterize the serviceability behaviour of ferrocement elements, it is equally important to predict their flexural strength. Wail N. Al-Rifaie 3 et al studied the structural behaviour using two ferrocement channel-like beams to form I-cross-section beam and indicated that ferrocement can be used in construction of buildings. Y. Yardim et al (8), investigated the performance of inverted two-way ribs precast ferrocement thin panel as permanent formwork and found that the thin panel with suitable ribs layout and support distance can be used as permanent formwork. Jalal.A. Saeed et al tested ferrocement one way slabs with openings subjected to two point loads taking into consideration number of mesh layers and size of the openings as variables. The results showed that by increasing number of mesh layers the slabs flexural strength increased and size of the openings have negative effect on flexural strength of the slabs. Essam Eltehawy observed the influence of using Ferrocement in enhancement of the mechanical properties of reinforced concrete slabs subjected to impact, penetration and fire. Deeptha Shri. S (1) studied the flexural behaviour of self-compacting concrete (SCC) ferrocement fiber reinforced slab panels. EXPERIMENTAL INVESTIGATION ferrocement slabs of dimensions mm x 3 mm and 5 mm thickness and welded mesh in, 3 and layers are tested under static and cyclic loading. Ordinary Portland cement, River sand and potable water are used. Welded wire mesh of 3mm diameter and 5 mm x 5 mm spacing is used. Chicken mesh is used on either sides of the layer formed. Normal binding wire is used to tie up the welded wire mesh with each other and chicken mesh to form the core of the slabs. 1:3 cement mortar with a water cement ratio of.8 was prepared. Fig1 Reinforcement of slab Fig. Reinforcement placed in the mould 58

3 International Journal of Civil Engineering and Technology (IJCIET), ISSN (Print), ISSN 97 31(Online) Volume, Issue 3, May - June (13), IAEME Fig 3. Test Setup Fig. Failure of slab The slab is placed under point load with dial gauge fixed to it as shown in fig 3 and tested till failure as shown in fig. RESULTS AND DISCUSSIONS The deflections were measured at the mid-span and the first crack and ultimate loads are noted. Static loading First Crack ing In static loading, the slab with 3 layer shows 8.75% increase in first crack load from the slab with layers. Similarly the slab with layers has increased by 87.5%. Hence the 3 layer slab shows considerable increase over the layers slab as shown in table 1 below. Table1: First Crack and Ultimate loads under static loading Sl. No. Specimen First Crack (kn) % increase in first crack load Ultimate % increase in Ultimate load 1 Layer 3.KN - 5.kN - 3 Layer 5.KN 8.75 % 8.kN 5 % 3 Layer KN 87.5 % 9.7kN 73.1 % Ultimate The ultimate failure is a bit low for the layer mesh slab, 5. kn. But the ultimate failure is relatively high for both 3 layer and layer mesh slabs i.e, 8. kn and 9.7 kn respectively. This shows an increase of 5% over layer slab. The layer slab shows an increase of 15.7% ultimate strength than 3 layer slab and 73.1 % over the layer slab. 59

4 International Journal of Civil Engineering and Technology (IJCIET), ISSN (Print), ISSN 97 31(Online) Volume, Issue 3, May - June (13), IAEME Deflection in mm in kn Fig 5. Deflection Curves (Static load) Fig. Deflection Curves (Cyclic load on layer slab) deflection Curves The load deflection curves were plotted for FC/L, FC/3L and FC/L as shown in fig. 5. The curves are almost linear for all the 3 slabs in static loading. But towards failure, there is a sudden increase in deflection. Hence the deflection increases gradually for lesser loads. And as the loads increase, deflection increases. Cyclic ing First Crack load In cyclic loading, the slab with 3 layer shows.15% increase in first crack load from the slab with layers. Similarly the slab with layers has increased by 89.7%. Hence the layer slab shows considerable increase over the layers slab. Ultimate load The ultimate failure is a bit low for the layer mesh slab, 3.9 kn. But the ultimate failure is relatively high for both 3 layer and layer mesh slabs i.e,.3 kn and 8. kn respectively. This shows an increase of 1.5% over layer slab. The layer slab shows an increase of 15.7% ultimate strength than 3 layer slab and 11.5 % over the layer slab Sl. No. Table: First Crack and Ultimate loads under cyclic loading Specimen First Crack (kn) % increase in first crack load Ultimate (kn) % increase in Ultimate load 1 Layer Layer % % 3 Layer % %

5 International Journal of Civil Engineering and Technology (IJCIET), ISSN (Print), ISSN 97 31(Online) Volume, Issue 3, May - June (13), IAEME deflecton in mm Deflection in mm load in kn in kn Fig 7. Deflection Curves (Cyclic load on 3 layer slab) Fig 8. Deflection Curves (Cyclic load on 3 layer slab) CRACK PATTERNS The cracks under flexure loading were observed to be parallel to each other, and they were in the plane perpendicular to load application. The cracks appeared on the face of the slab which was opposite to the face of load application. It is also observed that in the layer mesh slab, the first crack appeared very later, and the increase in the cracks, upon application of load was slow. CONCLUSIONS 1. Increasing the number of layers of mesh increases the flexural strength of the ferrocement slabs.. Slabs with highest number of layers of wire mesh have highest flexural strength under both types of loading. 3. The flexure strength under static loading increased by 5% % for 3 layer slab, from layer slab. It further increases by 15.7 % for layer slab over 3 layer slab.. The percentage increase of flexural strength of static loading condition of layer slab over layer slab is 73.1% 5. The flexure strength under cyclic loading increased by 1.5 % for 3 layer slab, from layer slab. It further increases by 9 % for layer slab.. The percentage increase of flexural strength of cyclic loading condition of layer slab over layer slab is 11.5% 7. As the number of layers increase the crack propagation is slow, and the crack spacing is least for layer mesh slabs, which ultimately leads to better load bearing capacities. 8. It was also seen that, as the number of layers increases, it is difficult to pack them into layer into same thickness 1

6 International Journal of Civil Engineering and Technology (IJCIET), ISSN (Print), ISSN 97 31(Online) Volume, Issue 3, May - June (13), IAEME REFERENCES 1. Anitha.M et. al. Coimbatore, India (1). An experimental investigation on the flexural behaviour of SCC ferrocement slabs incorporating fibres, International Journal of Engineering Science and Technology,Vol. ; No. 5; pp Ezzat. H. Fahmyet. al. Cairo, Egypt (9). Ferrocement sandwich and cored panels for floor and wall construction, our world in Concrete and structures. 3. Dr.Wail N. Al-Rifaie andmuyasser M. Joma ah, Tikrit, Iraq (1). Structural behaviour of ferrocement system for roofing, Diyala Journal of engineering sciences, pp Y.Yardim et. Al (1), Performance of Precast Ferrocement Panel for Composite Masonry Slab System, International Conference on Construction and Building Technology, 8, ICCBT 8 - B - (3) pp Jalal.A. Saeed, PaymanH. Mohammad, and lbrahimh. Aziz, (8). Behaviour and flexural strength of ferrocement one way slabs with square openings, Journal of Zankoy Sulaimoni, Vol. 1 No.1.. K. Sasiekalaa and R. Malathy, Flexural Performance of Ferrocement Laminates Containing Silicafume and Fly Ash Reinforced with Chicken Mesh, International Journal of Civil Engineering & Technology (IJCIET), Volume 3, Issue, 1, pp , ISSN Print: 97 38, ISSN Online: Mohammed Mansour Kadhum, Effect of Dynamic : Impact of Missile on Mechanical Behavior of Ferrocement Infrastructure Application, International Journal of Civil Engineering & Technology (IJCIET), Volume, Issue, 13, pp , ISSN Print: 97 38, ISSN Online: