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CHAPTER 1: INTRODUCTION

1.1 GENERAL:

Forged powder is the material used in the forging process which involves the process of pressing, pounding and squeezing the metal under great pressure into high strength parts. It is performed by preheating the metal to a desired temperature before it is worked. It is important to note that the forging process is totally different from the casting process, as the metal used to make the forged parts is never melted and poured as done in the casting process. Here mild carbon steel forged powders are used in this experiment.

Beam column joints are critical regions in a multi-storey moment resisting reinforced concrete frames subject to inelastic response under seismic excitation. Since seismic moments in columns and beams act in opposite directions across the joint, the beam-column joint is subjected to higher horizontal and vertical shear forces.

1.2 NEED FOR THE STUDY:

To ensure the safety of multi-storey buildings in earthquake prone zones.

The forged mild carbon steel is stronger than those manufactured by other metal working process and hence have great reliability.

To seismically strengthen a non-seismically designed building post construction by increasing its ductility, stiffness and energy dissipation.

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1.3 OBJECTIVES:

The objective of this work is to study the joint capacity of an exterior beam-column joint.

To design a beam-column connection using forged mild carbon steel and rubber polymers having higher strength than for a concrete member of same depth.

To significantly increase the joint’s ultimate capacity in such a way that the desired capacity of the beam-column joint can be attained without failure of the joints.

To compare the performance of retrofitted Exterior Beam – Column joints with mild carbon steel and rubber polymers fiber reinforced composite to that of conventional reinforced concrete.

FORGED MILD CARBON STEEL:

Forged powder is the material used in the forging process which involves the process of pressing, pounding and squeezing the metal under great pressure into high strength parts.

Any metal like carbon, alloy and stainless steels can be forged. It is performed by preheating the metal to a desired temperature before it is worked. Each metal has a distinct strength or weight characteristics that are suitable to various purposes.

ADVANTAGES OF USING FORGED MATERIALS:

Tougher than other alternatives. Can handle impact better than castings. The tight grain structure makes it mechanically strong. Uniformity in composition.

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CHAPTER 2: LITERATURE REVIEW

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CHAPTER 3 : MIX DESIGN (IS 10262:2009)

M30 OPC

1. Target strength for mix proportioning

= f ck+1.65 s

= 30 + 1.65*5

= 38.25 N/mm2

2. Selection of water cement ratio

Table 5, of IS 456: 2000, Maximum water–cement ratio = 0.55

Water cement ratio as per specification = 0.45

3. Selection of water content

From Table 2, maximum water content for 20mm aggregate = 186 litre

Water content for (100mm) slump (medium) = {186 + (6/100) *186} = 197.16 lit

= 197 litres

4. Cement Content

Water cement ratio = 0.45

W/C = cement content 0.45

Cement content = 197.16/ 0.45 = 438.13 kg/m3

Cement content = 438.17 kg/m3

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5. Proportion of volume of coarse aggregate and fine aggregate content

From Table 3, volume of coarse aggregate corresponding to 20mm size aggregate

and for water cement ratio of 0.50 = 0.60

Specified w/c ratio= 0.45

Corrected proportion of volume of coarse aggregate for the w/c ratio of 0.45 =

0.63

Volume of fine aggregate = 1 - 0.63= 0.37

6. Mix calculations:

a. Volume of concrete = 1 m3

b. Volume of cement =

massofcementspecificgravity

×1¿1000 ¿

¿¿

= (439/3.15) X (1/1000)

= 0.139 m3

c. Volume of water =

massofwaterspecificgravity

×1¿1000 ¿

¿¿

= (192/1) X (1/1000)

= 0.192m3

e. Volume of all in aggregate = (a-(b+c)) = (1-(0.139+0.192))= 0.669 m3

6. Mass of coarse aggregate = 0.669x0.63x2.41x1000= 1113 kg

7. Mass of fine aggregate = 0.669x0.37x2.68x1000= 664 kg

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The mix proportion then becomes:

Water : Cement : Fine aggregate

:

Coarse

Aggregate

192 liters : 439 kg :664 kg : 1113 kg

The mix ratio is 1:1.51:2.53

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CHAPTER 4 : COMPRESSIVE TEST RESULTS

The compressive test after 28 days was done on the cubes and cylinders and the results are tabulated below:

S.NO MIX DESIGNATION

CURING DURATION

SPECIMEN NO COMPRESSIVE LOAD (KN)

STRESS (N/mm2)

1 1 : 1.51 : 2.53 28 Days CUBE 1 786 34.93

CUBE 2 793 35.11

CUBE 3 816 36.26

2 1 : 1.51 : 2.53 28 Days CYLINDER 1 162 1.149

CYLINDER 2 173 1.22

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COMPRESSIVE TEST OF THE CYLINDER

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CHAPTER 5: SCALING DOWN OF PROTOTYPE

5.1 SCALING DOWN OF PROTOTYPE

In general a scale model must be designed and built primarily considering

similitude theory. Similitude is the theory and art of predicting prototype (original object)

performance from scale model observations. The main requirement of similitude is

all dimensionless quantities must be equal for both the scaled model and the prototype

under the conditions the modeler desires to make observations. For structural engineering

scale models, it is important for several specific quantities to be scaled according to the

theory of similitude. These quantities can be broadly grouped into three

categories: loading, geometry, and material properties.

5.2 REQUIREMENTS OF SIMILITUDE

The scale factor is defined as the ratio of the quantity of the prototype to that of the

model.

a. The strain of the prototype must be equal to that of model. Thus strain scale factor

is one (Sϵ = 1).

b. The Poisson’s ratio of model and prototype are equal (Sµ = 1).

c. The length scale factor must be same in all direction (SL = LP/LM).

d. The stress scale factor and pressure scale factor are one as the materials of

prototype and model are same (Sσ = 1, SP = 1).

e. The force scale factor depends on stress and length scale factors

(SF = Sσ x SL2).

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5.3 SPECIMEN DIMENSIONS

The model or test specimen is achieved by scaling down the prototype with the

ratio of 1 : 2.

Thus, The length scale factor, SL = LP/LM = 2 (No units)

The area scale factor, SA = SL2 = 4 (No units)

The Force scale factor, SF = Sσ x SL2 = 4 (No units)

The moment scale factor, SM = SF x SL= 8 (No units)

Beam Specimen:

Width of beam specimen, BM = BP/ SL = 300/2 = 150 mm

Depth of beam specimen, DM = DP/ SL = 300/2 = 150 mm

Area of Steel in model, AMst = APst/SA = 305/4 = 76.25 mm2

Provide two numbers of 8 mm diameter bars.

Column Specimen:

Width of Column specimen, BM = BP/ SL = 300/2 = 150 mm

Depth of beam specimen, DM = DP/ SL = 300/2 = 150 mm

Area of Steel in model, AMst = APst/SA = 804/4 = 201 mm2

Provide four numbers of 8 mm diameter bars.

Axial compression force, FM = FP/SF = 425/4 = 106.25 kN

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CHAPTER 6: MATERIAL TESTS

The following tests are to be performed to check the suitability of forged mild carbon steel powder used in the retrofitting process:

1. Mechanical and Physical Testing:

i. Tensile

ii. Imapct

iii. Compression

iv. Dynamic testing.

2. Corrosion testing:

i. Environmental corrosion

ii. Pitting corrosion

iii. Resistance of materials to stress corrosion.

3. Specialized Non-Destructive Testing (NDT) :

i. Ultrasonic flaw detection

ii. Portable hardness detection.

iii. Raw material inspection.

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REFERENCES

1. Architectural Institute of Japan, “AIJ Standard for Structural Calculation of Reinforced Concrete Structures”, revised in 1982.

2. ACI-ASCE Committee 352 , “Recommendations for Design of Beam-Column Joints in Monolithic Reinforced Concrete Structures”, ACI Journal, May-June 1985, pp.266-283.

3. Alj. Design guidelines for earthquake resistance reinforced concrete buildings based in inelastic displacement concept. Alj ;1999.p.440.

4. Mehta PK. Concrete technology for sustainable development 1999;21(11):47-53.5. Sudarsana Rao H., Ramana N.V (2008). Behavior of steel reinforced slurry

infiltrated fibrous concrete two-way slabs in flexure with two adjacent simply supported and other two edges fixed. Indian Journal of Engineering & Material Scienes 1-6.

6. Uchikawa H. In cement and concrete industry. J Mater civil eng 2000;12(4):320-9.7. Attala SA. General analytical model for nominal shear stress of type 2 normal and

high strength concrete beam-column joint. ACI Struct J 2004;101(1):65-231.8. D.S. Ramachandra Murthy et al “Seismic Resistance of Reinforced Concrete Beam-

Column with TMT and CRS Bars”, ICJ Journal, July-Sept 20009. S.R.Uma and A.Meher Prasad, “Analytical model for beam-column joints in R C

frames under seismic conditions”, Journal of Structural Engineering Vol. 30,No:3,October 2003.

10. Rao,H.s and Ramanan N.V (2005) Behaviour of slurry infiltrated fibrous concrete (SIFCON) simply supported two way slab in flexure .Indian Journal of Engineering & Material Science

11. Sudarsan Rao H. , Gnaneswar k. and Raman N.V (2008) Behaviour of steel reinforced slurry infiltrated fibrous concrete (SIFCON) simply supported two way slab in flexure with two adjacent edges simply supported and other two edges fixed . .Indian Journal of Engineering & Material Science