Experimental study of precast portal frame

EXPERIMENTAL STUDY OF PRECAST

PORTAL FRAME

2CL404 – CIVIL ENGINEERING PROJECT

ee

Presented By:-

SAGAR HALWAWALA (11BCL014)HIMANSHU MANOLKAR (11BCL015)SATISH KAMBALIYA (11BCL016)MEET KOTADIA (11BCL020)

Guided By:-Dr. P.V. Patel

Introduction

• Precast concrete :- Construction product produced by casting

concrete in a reusable mould or "form" which is then cured

in a controlled environment, transported to the construction

site and lifted into place.

• Increasingly popular in the construction industry.• Increasingly popular in the construction industry.

• Also referred to as Modern Methods of Construction (MMC).

• Extensively used for a wide variety of projects, from railway

sleepers to bridge elements, housing and stadia.

• Reduction in waste on construction site by as much as 50%

when compared to more traditional approaches.

Introduction cont...

• It is due among other factors to the advantages related to the

reduction in construction times, work force and in situ labors,

as well as a more favorable cost-benefit relation, less

environmental impacts, and greater control and final quality

of the elements.

• Utilizing a Precast Concrete system offers many potential• Utilizing a Precast Concrete system offers many potential

advantages over site casting of concrete. The production

process for Precast Concrete is performed on ground level,

which helps with safety throughout a project.

• There is a greater control of the quality of materials and

workmanship in a precast plant rather than on a construction

site.

Types of Precast System.

Depending on the load bearing structure, precastsystems can be divided into the followingcategories:

� Large-panel systems

� Frame systems

�Slab-column systems with walls

�Mixed systems

�Volumetric construction

Precast Components

Precast Building In India

Pragati Tower is a

G+23 storeys fully

precast residential

building project with

6 towers at6 towers at

Bhoiwada, Parel,

Mumbai, India to

rehabilitate slum

dwellers.

Need Of Precast Construction

• Precast concrete solutions can provide construction elements thatare made of recycled materials that generate small amounts ofwaste through the manufacturing and erection phases. Theseprecast products are widely used in the following sectors:

� Residential (floors)

� Stadia� Stadia

� Infrastructure (roads, railways, bridges, sewage)

� Prisons

� Medium and high rise building

� Hospitals

� Commercial and industrial buildings

Need Of Precast Construction cont.

• Their utilization saved construction time and cost,

insured better quality control, and suggested the

achievement of standardization.

• Its fulfills criteria of three “R” of Sustainable

Development ie.Development ie.

� Reduce

� Recycle

� Reuse

Advantage Of Precast Construction

• Quick erection times.

• Reduced need for plant on site.

• Easier management of construction sites.

• Better overall construction quality.• Better overall construction quality.

• Ideal fit for simple and complex structures.

• The forms used in a precast plant may be reusedhundreds to thousands of times before they haveto be replaced, which allow cost of formwork perunit to be lower than for site-cast production.

Limitations

• High Initial cost.

• Lack of local availability of elements.

• Transportation

• Erection• Erection

Objective Of Project

The key objectives of study are as follows.

• To study the basics of precast joints.

• To study the behaviour of joints in precast concrete• To study the behaviour of joints in precast concrete

portal frame by experimental study.

• To compare experimental results of monolithic

specimen and precast specimens (with and without

corbel) and derive conclusion which is comparatively

efficient.

Scope Of Study

• Analysis and design of the Portal Frames.

• Taking a building with continuous slab and designing

intermediate portal frame from it.

Scope Of Study

• Designing of a monolithic portal frame andtwo precast portal frame one with corbel andone without corbel.

• Casting of the scaled down specimen of each• Casting of the scaled down specimen of eachtype of the portal frame.

• Testing the portal frame as per experimentalsetup.

• Based upon experimental data, comparingportal frames and deriving out conclusion.

DESIGN OF PORTAL FRAMESDESIGN OF PORTAL FRAMES

MIX DESIGN

• Design Data

1. Characteristic strength required at 28 days = 25 MPa

2. Maximum size of aggregate = 10 mm2. Maximum size of aggregate = 10 mm

3. Degree of workability = medium

4. Degree of quality control = fair

5. Type of exposure = Moderate

• Test data of materials:-

1. Compressive strength of OPC cement 53

N/mm2

2. Specific gravity of cement = 3.152. Specific gravity of cement = 3.15

3. Specific gravity of coarse aggregate = 2.78

4. Specific gravity of fine aggregate = 2.54

Final Mix Design

Concrete

Grade

Cement

OPC 53

W/C Coarse

Aggregate

Fine

Aggregate

grade

M-25 1 0.54 2.51 1.96

M-25 390 kg 210.6 978.84 kg 762.61 kg

Design Consideration

• Three test specimens of one forth scale model were cast and

tested under two point load. The design and detailing of

portal frame had been done based on the guidelines given in

IS: 456-2000, IS: 13920.

• Dimension of actual portal frame of :-• Dimension of actual portal frame of :-

1. Span – 8m

2. Height – 4m

3. Cross section of beam- 400x600

4. Cross section of column – 400x800

Designed Portal Frame

Dimensional Analysis and Scaling Of

Portal Frame

• As large specimens were difficult to handle so casting

of scaled down specimen for study.

• Therefore using Buckhimgam Pie theorem and taking

a reduction factor of 1:4 calculation were made and

following model was decided for experimental

testing.

1. Span – 2m

2. Height – 1m

3. Cross section of beam- 100x150

4. Cross section of column – 100x200

Scaled Down Portal Frame

Reinforcement Detailing Of Monolithic

Portal Frame

Precast Portal Frame

1).Without Corbel

• This frame design consists of a L shapedcolumn spanning 300 mm out of column with150mm bars projecting out, accompanied150mm bars projecting out, accompaniedwith 900mm beam casted separately with150mm bars projecting out, welding of110mm on either side of the beam with a gapof 150mm in between the beam approachingbeam from column side.

1). Detailing Of Portal Frame Without

Corbel

2). With Corbel

• In this frame corbel of 110 mm long and

200mm depth were designed having two

dowel bars in corbel and two M10 bolts were

used.

• Beam 1770mm long having hole for bolts

were designed and welding of 110 mm of

columns bar and beam bar were done.

• 15mm spacing were kept on both side of

beam for concreting.

Detailing Of Portal Frame With Corbel

EXPERIMENTAL PROGRAMME OF

PORTAL FRAME

EXPERIMENTAL PROGRAMME OF

PORTAL FRAME

Steps for Experimental Analysis

1. Trial mix for the concrete mix design

2. Casting of covers (20mm)

3. Setting up of form work

4. Tie up the reinforcement cage4. Tie up the reinforcement cage

5. Connection of column and base plate by welding

6. Placement of the reinforcement cage into the formwork

7. Casting of the Portal Frame

8. Curing

9. Setting up of portal frame in test set up frame

Trial mix for the

concrete mix

design

Three cubes of

150*150*150mm were150*150*150mm were

casted as per obtained mix

design for M25 grade of

concrete and were tested

for 7 days strength.

The cubes were

tested on Universal

Testing Machine after

seven days and result

obtained was 16.5

N/mm^2. Which is

66% of 25N/ N/mm2.66% of 25N/ N/mm .

Casting of covers

(20mm)

• Tea cups were used forcasting of mortar coverhaving proportion of1:2. and then bindingwire were inserted in it.

• Cups were kept in waterand cured for threedays.

1).Methodology For Monolithic Portal

Frame

Tie up the

reinforcement cagereinforcement cage

of column

•Column with end to

end length of 1075mm

and beam with end to

end length of 2200 mm

was casted.

Reinforcement cage of Beam

Placement of

reinforcement

cage into

formwork

•8 mm thick steel plate

was used to serve purpose

Connection of

column and base

plate by welding

was used to serve purpose

of footing for stability of

the frame.

•Reinforcement bars of

column at bottom was

welded with plate by

120mm length.

• Wooden logs were firmly kept for connecting base

plate to form work.

•Casting of frame were performed,

vibrator was used for removing the voids.

Cubes were arranged on sides of were

to prevent expulsion of formwork and to

have desired shaped frame.

Casting of the

Portal Frame

Curing

•After Casting, curing were done for 28

days and gunny bags were used for this

purpose.

•After 28 days of casting, the frame was

arranged as per set up.

Setting up of

frame in test

set up and

Measuring

Verticality of

frame with

plumb bob.plumb bob.

Test Setup

• Test setup consists of loading frame on which four ISMB 150

were rigidly fixed by the means of metal nuts, bolts and wires.

Upon this portal frame having base plate 8mm thick is

connected to the ISMB 150 by the help of clamps.

Furthermore the testing assembly consists of 5 dial gaugesFurthermore the testing assembly consists of 5 dial gauges

placed at 100mm, 450mm, 1000mm, 1450mm and 1900mm

from the left hand side respectively.

• For application of load a 250 kN hydraulic jack is mounted at

the top of the loading frame facing downward side below

which an ISMB 200 section was placed over two roller support

330mm from the middle of the support on either side.

2).Methodology For Precast Portal

Frame without Corbel

•Placing

Reinforcement Cage

into formwork of 900

mm long.

•Bars extending on

both sides of 130mm

long for connecting it

to bars of column.

Different components were arranged in level to have proper connections.

Reinforcing Bars extending from columns and Beams are welded of length 110mm

with the help of mobile welder.

•Placing of form work for Micro Concreting, which were

sealed with M-seal in order to prevent leakage.

Using Micro-concrete in proportion of 1:2 with proper stirring, and

pouring Micro Concrete and curing it for 28 days.

Setting up the Frame in the laboratory with the help of crane which is electrically operated.

Grinding the surface for making it even and checking the verticality with the help of spirit level.

Test Setup

• Two beam of ISMB 300 were kept at end and over it beam of

ISMB 500 were kept and above it specimen were kept. Above

specimen two rollers of 50mm were kept for providing

support and above it beam ISMB 200 were kept and spacer of

100mm were used and then jack of 100kN, 300mm height

were used thus completing full length of 2000mm height.were used thus completing full length of 2000mm height.

• For application of load a 100kN hydraulic jack is mounted at

the top of the loading frame facing downward side below

which an ISMB 200 section was placed over two roller support

330mm from the middle of the support on either side.

3).Methodology For Precast Portal

Frame with Corbel

In this frame

Corbel of size

110*110*200

and two Dowel

Bars of 10mmBars of 10mm

diameter are

designed.

Binding of M10 bolts with Dowel Bars

Placing of PVC pipes in beam for maintaining holes for bolts

Fixing the bolts emerging out from the column into the beam and welding the Reinforcing

Bars of column and beam with the help of mobile welder, then Micro concreting is done.

•After casting of Pre-cast

elements, Micro-concreting is

done by proper stirring in

proportion of 1:2.

•And curing it for 28 days.

•Then setting up the frame in the

laboratory, and test setup islaboratory, and test setup is

similar to that of frame without

corbel.

EXPERIMENTAL RESULTS OF EXPERIMENTAL RESULTS OF

PORTAL FRAMES

Results Of Monolithic Portal

Frame

40

50

60

LOA

D (

kN

)

Load vs Deflection

900L

0

10

20

30

0 5 10 15 20 25 30

LOA

D (

kN

)

DEFLECTION(mm)

900L

450L

centre

900R

450R

Results Portal Frame without

Corbel

Results Portal Frame with Corbel

30

40

50

60

70

80

90LO

AD

(KN

)LOAD VS DEFLECTION AT 100 mm FROM LEFT

0

10

20

30

-1 0 1 2 3 4 5 6 7 8

DEFLECTION(mm)

Monolithic Without Corbel With Corbel

40

50

60

70

80

90

LOA

D(K

N)

LOAD VS DEFLECTION AT 550 mm FROM LEFT

0

10

20

30

0 2 4 6 8 10 12 14 16

LOA

D(K

N)

DEFLECTION


40

50

60

70

80

90

LOA

D(K

N)


0

10

20

30

0 5 10 15 20 25 30

LOA

D(K

N)

DEFLECTION


40

50

60

70

80

90

LOA

D(K

N)


0

10

20

30

0 5 10 15 20

LOA

D(K

N)

DEFLECTION


40

50

60

70

80

90

LOA

D(K

N)


0

10

20

30

0 2 4 6 8 10

DEFLECTION


Observation For Cracks Of Monolithic

Portal Frame

Observation For Cracks Of Portal

Frame without Corbel

Shear crack

observed at

52.5 kN. @left

corner of

frame

Tension

Crack

observed

at 60.5

kN @ top

at corner

on both

side

Crack

observed

between point

load and

centre @ 65.0

kN

Crack

observed at

67.5 kN

Crack

observed at

connection @

70 kN

Cracks

Observed

@ 72.5

kN

Major Crack

observed at

connection @

80 kN at point

load

Observation For Cracks Of Portal

Frame with Corbel

Shear

Crack

observed

at 50 kNat 50 kN

Minor Crack

Observed at

point load @

55 kN

Minor Crack

Observed

between center

and point load

@62.5 kN

Major Failure at 67.5 kN

Summary• In this study taking a building with continuous

slab and designing intermediate portal framefrom it.

• Further casting and testing of one forth scaledspecimen of monolithic portal frame , and twospecimen of monolithic portal frame , and twoprecast portal frame one with corbel and onewithout corbel were carried out.

• Testing of the portal frames were done as perexperimental setup.

• Based upon experimental data, comparingportal frames and deriving out conclusion.

Conclusion• Deflection pattern through out the testing followed

similar pattern i.e. maximum deflection is observed incase of monolithic frame, than portal frame withoutcorbel followed by portal frame with corbel.

• This shows that Monolithic Frame is more ductile thanPre-cast Frame, but carries low load.Pre-cast Frame, but carries low load.

• However it is observed while testing portal frame withthe corbel that deflection at center of span weresimilar to deflection at 450mm distance on both side ofcenter.

• However this could be attributed to presence of thecorbel as due to presence of corbel proper fixity is notobtained at support and there is rotation which wouldresults in similar kind of deflection.

28.4

15

20

25

30

De

fle

ctio

n(k

N)

Maximum Deflection of Portal Frame(mm)

10.1

12.8

0

5

10

15

With Corbel Without Corbel Monolithic

De

fle

ctio

n(k

N)

55

67.5

80

40

50

60

70

80

90

Ult

ima

te L

oa

d(k

N)

Ultimate Load

monolithic with corbel without corbel

load 55 67.5 80

0

10

20

30

40

Ult

ima

te L

oa

d(k

N)

Type of system

• Load carrying capacity of frame without corbelis 15% more than frame with corbel and 31%more than monolithic frame.

• Deflection is also between monolithic andwith corbel frame.

• Thus portal frame without corbel is more• Thus portal frame without corbel is moreefficient comparatively.

• After going through study it can be wellconcluded that the precast construction canperform well unconventional to that of theexisting belief.

Thank YouThank YouThank YouThank YouThank YouThank YouThank YouThank You

Experimental study of precast portal frame

Education

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