study on the behavior of r.c.c. beam-column junction · using a table vibrator to give vibration to...

International Journal of Technical Innovation in Modern Engineering

& Science (IJTIMES) Impact Factor: 5.22 (SJIF-2017), e-ISSN: 2455-2585

Volume 4, Issue 8, August-2018

IJTIMES-2018@All rights reserved 659

Study on the Behavior of R.C.C. Beam-Column Junction

Manish Pagani, Dr. M. K. Maroliya(Associate Professor)

Applied Mechanics Department

Faculty of Technology & Engineering. M. S. University, Vadodara, India

Abstract— In recent years, the growth of infrastructure is rapidly. The demand of client is to construct with better quality and

also in short time. In R.C.C. structures the common portion of beam and column and also a critical section is called beam –

column joint. The beam – column joints play a critical role in R.C.C. structures.

In this study we are going to compare the behavior precast and cast in situ beam column joint. Casted two specimens of

precast and two specimens of cast in situ specimens of same size and same design. Using Fe-415 and M:20 grade of concrete

(nominal mix) to prepare a both specimens. The height of column of all four specimens is 1350 mm. Cross section of column

is 150×150 mm. Span of beam is 700 mm and cross section of beam is 150×150 mm.

To prepare a precast specimens casting of column and beam separately and joint beam and column with grouted material.

Using a table vibrator to give vibration to the specimens during concreting. A load is given by hydraulic jack of 500kn capacity

at a corner of the beam and used proving ring to measure the load.

Keywords— Beam, Column, Precast Concrete, cast in situ, beam column junction.

I. INTRODUCTION

As we know the R.C.C structures can be constructing by several methods. Common method generally used in India is cast in situ.

Now we all know the importance of time so we developed a new technique called precast. Not only the time but there are many

advantages of precast structures on cast in situ structures i.e. ready high raised buildings in a short time, no need of scaffolding

and formwork, need a less labors but skilled labors, initial cost of precast structures may be high but at last it is much cheaper

than cast in situ structures.

As in precast structures the parts of whole structures like beam column slabs already casted on industry only we need to transfer

it on site and joint them by grouting material or any dry method we can use.

Only a major difference in precast and cast in situ structure is of beam column joints and we know that is a critical part of the

structures.

So prepare a specimens using same design and material of precast and cast in situ specimens and tested them under static load and

see the results of performance of beam column joint of both specimens.

II. ADVANTAGES OF PRECAST ON OTHER STRUCTURES

1. Precast buildings have a great fire rating and often times eliminate the costly process of fireproofing.

2. Precast buildings are safe and sufficiently strong enough to resist impacts and natural catastrophes such as tornados, floods and

earthquakes.

3. Since precast is manufactured in a controlled indoors environment it is easier to control the mix, placement and curing for a

more consistent product.

4. Required less labors as compared to requirements of labors on other structures.

5. No need of scaffolding and formwork, and can be construct in any environmental condition.

6. Fast construction as compared to cast in situ structures.

International Journal of Technical Innovation in Modern Engineering & Science (IJTIMES) Volume 4, Issue 8, August-2018, e-ISSN: 2455-2585, Impact Factor: 5.22 (SJIF-2017)


III. SCOPE AND OBJECTIVE OF STUDY

A beam-column joint is a very critical zone in R.C.C. structures.

1. To design the beam-column connection for laboratory testing.

2. Design beam and column as per IS 456:2000.

3. Preparation of mould, reinforcement and casting of precast and cast in situ specimens.

4. Testing of all specimens under static load.

5. Comparison between the performance of connection of precast and cast in situ specimens under static load.

IV. DESIGN AND DETAILS OF SPECIMEN

Design of precast and cast in situ specimens as per IS 456:2000

Size of beam and column are given below

1) Cross-section of column=150 × 150 mm2

2) Cross-section of beam = 150 × 150 mm2

3) Height of the column =600 mm

4) Total height of both column with beam= 1350 mm

5) Span of beam =700mm

6) Grade of steel – Fe-415

7) Grade of concrete – M:20 (nominal mix)

V. CASTING OF SPECIMEN

Used M:20 grade of concrete and Fe-415 steel grade for all specimens. Casted two precast and two cast in situ specimens.

Casting of precast specimen casting of precast beam column junction in four steps.

1. Cast column at 600 mm.

2. Cast beam and left four holes of 25 mm diameter at a corner of beam.

3. Grouting all four holes of beam which were inserted in column.

4. Insert beam in column and remaining reinforcement of 600 mm will be concreting.

Casting first column of precast at a distance of 600 mm as shown in fig. Remaining reinforcement of 750 mm is kept open for

inserting beam.

Precast beam and column casted separately, curing method of precast beam and column were also done by different method as

beam kept in tank and column curing done by Hassan begs to avoid corrosion of steel.

Before inserting beam in column, we make a temporary structure by cement blocks of similar height of column to support a beam

during grouting and maintaining alignment.So smooth grouting can be possibleBefore grouting of specimens all holes were clean

by slurry, rebaring material (fischer) used as a grout material for grouting the specimens.

Fig. 1 Precast beam



Fig. 2 Grouting of beam column joint.

After grouting specimen left for 2-3 hours for hardening of grout material and remaining portion is casted on next day.

For casting of precast beam column and cast in situ specimen we used table vibrator to avoid voids in concrete but only in precast

2nd

column we have to use a needle vibrator because column 1st and beam were in plastic stage so in table vibrator whole model

would vibrate and it can affect junction.

Fig.3 final casting of precast column.

Fig. 4 Cast in situ specimen before and after casting.



VI. TEST SET UP IN LABORATORY

Fig 5 shows the laboratory arrangement of specimen for testing.

Where,

D1 = dial gauge 1st used at corner of beam to measure deflection of beam.

H = distance between dial gauge 2nd and 3rd.

One end of the column was at strong ground, and the other end was laterally restrained by a jackfrom loading frame. A specimen

was restrained by given a load by jack on upper side ofcolumn.

At end of the beam hydraulic jack were used to give a gradually load on beam.

Proving ring placed between hydraulic jack and beam to measure a load reading given by jack tothe beam.

Fig 5 Test setup in laboratory.

VII. PROCEDURE OF TESTING

1. Specimen arranged in laboratory as shown in fig. 5

2. Given a load from jack to the column to restrained specimen during testing

3. All dial gauges keep as shown in fig 5

4. Measure distance between dial 2nd and dial 3rd = H

5. Give a gradually increasing load to corner of the beam by hydraulic jack as shown in fig.

6. Take a reading of proving ring for measure load.

7. Take a reading of dial 1st for deflection and dial 2nd and dial 3rd for measure rotation of beam.

8. Plot a load deflection curve.

9. Calculate moment from load

10. Plot moment rotation curve.



Fig. 6 setup of specimen for testing.

Used a 15-tone jack at the face of the column to restrain specimen during testing when load is applied on free end of the beam.

VIII. RESULT AND DISCUSSION

Fig 7 Experimentally load vs deflection curve for Precast– 1

Fig 8 Experimentallyload vs deflection curve for Precast -2

0

2

4

6

8

10

12

14

16

18

LOA

D (

KN

)

DEFLECTION (MM)

P-1

PRECAST 1ST



Fig 9 Experimentallyload vs deflection curve for Cast-in-situ -1

0

2

4

6

8

10

12

14

16

18

LOAD

(KN

)

DEFLECTION (MM)

C-2

CAST IN SITU 2ND

Fig 10 Experimentally load vs deflection curve for Cast-in-situ -2

Fig 11 failure of Precast-1 specimen.

0

2

4

6

8

10

12

14

16

18

LOA

D (

KN

)

DEFLCETION (MM)

C-1

CAST IN SITU 1ST



FIG 13 LOAD VS DEFLECTION CURVE FOR PRECAST 1

IX. CONCLUSION

The beam column connection is most important structural element in reinforcement concrete building. In present study, a

numerical investigation to the experimental work on behavior of beam column connection under gradually increasing load was

carried out. The effect of load on beam column junction of precast and cast in situ specimen was studied. The following

conclusion or observation can be drawn.

1. The failure mode of beam column connection was classified to gradually fail.

2. From the experimental results it was observed that the ultimate load carrying capacity of precast specimens is almost

same as cast in situ specimens.

3. It was carried out experimentally that deflection with respect to load were more of precast as compared to cast in situ

specimens so stiffness of beam of monolithic connection is more than precast specimen.

4. From result of current study, it is observed that precast connection can be used as replacement of cast in situ connection

with some modification in design.

X. REFERENCES

Seismic evaluation of r/c moment resisting frame structures considering joint flexibility

13th world conference on earthquake engineering vancouver, b.c., canada august 1-6,2004 paper no. 2799Uma s.r.1 and

Meher prasad

Reported the performance of exterior beam column joints with cross inclined bars under seismic type loading, ISET journal

of earthquake technology, paper no. 503, vol. 46, no. 2, june 2009, pp. 47-64Bindu et al. (2008)

Studied on seismic analysis of steel braced reinforced concrete frames.International journal of advance research, ideas and

innovations in technology issn: 1245impact factor: 4.295 (volume 4, issue 2) Viswanath k.g et al (2010)

Experimental study on behavior of interior rc beamcolumn joitns subjected to cyclic loadindInternational journal of applied

engineering research,dindigul volume 1, nol,2010P.rajaram, A.murugesan and G.S.thirugnanam

Seismic behavior of beam-column joint using gfrp bars in multi-storey building using etabsISET journal of earthquake

technology , paper no. 503 , vol. 46,no.2, june 2009,pp 47-64Radhika et al.

Behaviour of discontinuous precast concrete beam-column connections.Thesis submitted to the university of nottingham for

thedegree of doctor of philosophySarakotasaadhasan, (2011)

Seismic evaluation of beam-column joints using gfrpbars in multi-storey building using etabs,international journal of

advanced engineering research and studies e-issn2249–8974Radhika j. popat1, et al. (2011)

(2015), pp. 39- 49M. N. kataoka, et al. (2012)

An experimental study to evaluate performance of wet precast beam column connectionsDigesh d. joshi, Paresh v. patel

Study on the behavior of beam-column connection in precast concrete structure computer and concrete , vol. 16,no.1 (2015)

163-178 Marcela n. kataoka, marcelo a. ferreira and analúciah.c. el debs

Numerical investigationofrc exterior beam colum connections under monotonic loads Volume 13, issue 1 ver. vi (jan-feb

2016),pp 60-67 Ahmed g. asran1, hassan h. el-esnawi2, sabryfayed3

IS 456 (2000): Plain and Reinforced concrete – Code of practice [CED 2: Cement Concrete]

0

2

4

6

8

10

12

14

16

18

0.0000 5.0000 10.0000 15.0000 20.0000 25.0000

LOA

D (

KN

)

DEFLECTION (MM)

LOAD VS DEFLECTION

precast -1

precast - 2

cast in situ - 1

study on the behavior of r.c.c. beam-column junction · using a table vibrator to give vibration to...

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