ACC Presentation AT APM DEPT (221) (1).pptx

ACC

1. WALCHAND COLLEGE OF ENGINEERING, SANGLI Presentation on Mechanical Properties Of Ferrocement Presented by Ms. Sanika Ramesh Mali (22151008) Guide HOD PROF. A. S. PATANE PROF. DR. S. N. TANDE 1

2. CONTENTS Introduction History Casting Methods Behavior of Ferrocement in tension mechanical Properties of Ferrocement concrete 2

3. Introduction Ferrocement is a special form of reinforced concrete It is a composite material consisting of cement, sand, mortar reinforced with closely spaced layers of continuous and relatively small diameter wire mesh The mesh may be made of metallic or other suitable materials It Overcomes the drawbacks of normal cement concrete Materials used are: Cement Mortar Mix Skeleton steel mesh 3

4. History One of the first application of ferrocement was the model of boat built by Lambot in France in 1856 Little progressive activities until 1942 In 1942 Dr. Pier Luigi Nervi began a series of experiments on Ferrocement He Observed reinforcing cement mortar with layers of wire mesh produced a material capable of resisting high impact load 4

5. Cross sections of ferrocement concrete 5

6. Components of ferrocement concrete Cement mortar mix 1. Cement 2. Sand 3. Water 4. Admixture Skeleton steel Mesh Square welded wire mesh Square woven wire mesh Hexagonal wire mesh Expanded metal lath 6

7. Square welded wire mesh 7

8. Square woven wire mesh 8

9. Hexagonal wire mesh 9

10. Expanded metal lath 10

11. Expanded metal mesh forming 11

12. Casting Methods Hand Plastering Semi mechanised process Centrifuging Guniting 12

13. Hand Plastering The minimum thickness of section that can be casted works out to be 2 cm Strength obtained is lower Easy to use in the situation where other improved methods can’t be used 13

14. Simultaneous Plastering 14

15. Semi Mechanised Process This system is termed as semi mechanised because the mould can be rotated to facilitate dashing of mortar Better compaction than earlier process Better uniformity Do not require any sophisticated equipment and machinery 15

16. Centrifuging Commonly adopted for the fabrication of cylindrical concrete units Ferrocement pipe cast by centrifuging can be used as pressure pipe due to good compaction 16

17. Guniting Used for applying the mortor to the wire mesh system This process applies with experienced gunman, can give compact and uniform surface 17

18. Mechanical Properties of Ferrocement Tensile Strength Compressive Strength Flexural strength Impact Resistance Low w/c ratio produces impermeable structure Less shrinkage and low weight Undergo large deformation before cracking or high deflection Poor resistance to fatigue under cyclic loading 18

19. Ferrocement jacketed spacimen formation 19

20. Tensile strength Depends mainly on the volume of reinforcement in the direction of force and tensile strength of mesh Tension Behaviour divided in three regions Pre-cracking stage Post-cracking stage Post-yielding stage Under increasing tensile stress the material act as linear elastic material till first crack Multiple cracking stage continues till the point when wire mesh start to yield Then number of crack remains constant and crack width starts increasing 20

21. Tensile strength test 21

22. Behavior of Ferrocement in tension 22

23. Depending on cracking behaviour the ferrocement curve exhibits three different regions Elastic region Quasi Elastic region Elastoplastic region 23

24. Compressive Strength The behavior of thin ferrocement element under compression is primarily controlled by the properties of the cement-mortar matrix 24

25. Flexural Strength The mesh r/f in flexural members may placed in the form of bundles at top and bottom General flexural strength of RCC member: 2.7 N per sq. mm Ferrocement: 10-25 N per sq. mm 25

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27. Impact Resistance Impact resistance increases almost linearly with increase in specific surface and ultimate strength of mesh reinforcement Ferrocement with; Welded wire mesh: Highest impact resistance Chicken wire mesh: lowest impact resistance Woven mesh: Higher than chicken mesh and lower than welded mesh 27

28. Thank You… 28