Experimental Study on G.I Sheet Encased to Concrete and Exposed to Temperature

Experimental Study on G.I Sheet Encased to Concrete and Exposed to Temperature

1. Lakshmi Praganya 1 B.E., S. Naveen Raj2 B.E., S. Sadam Hussain3 B.E,.

   1,2,3PG Student, Department of Civil Engineering,

   1. A. M. College of Engineering and Technology, Trichy,

      1. Ananthakumar4 M.E.,

4Asst. Prof, Department of Civil Engineering,

M. A. M. College of Engineering and Technology, Trichy

Abstract:- The aim of this experimental study is to determine the strength of galvanized iron (G.I) sheet encased concrete and sorptivity. In recent years G.I tube encased to concrete have been widely studied for their use in the civil infra structure. G.I sheets of two varying thicknesses are used. Generally concrete has high strength properties, even though it has high strength it undergone damage because of its porous nature. Sorptivity test for concrete cube is done to determine its water absorbing capacity. Electrical oven is used for distribute the temperature to the G.I encased concrete cylinders. The cylinders are kept in oven at different temperatures of 100c, 150c, 200c, and 250c with the time periods of 5hrs. Experimental tests are conducted for determining the strength of G.I encased concrete after temperature distribution and Sorptivity for cover concrete.

INTRODUCTION

General

Concrete columns are fundamental structural component in engineering structures. The G.I encased concrete cylinders are increasingly becoming important in infrastructure because the G.I tube serve as stay in place formwork during construction and provide confinement during service, in addition to the resistance to corrosion upto ambient temperatures.

G.I encased concrete are releasing the moisture content and odour. This type of concrete are does not release any fumes. This G.I encased concrete also used for high rise buildings and bridges. Because of gives the better corrosion resistant and good appearance. The galvanised iron is easily available material.

It will further cause decomposition of G.I as a result, the

G.I will lose their confinement effect and the concrete concrete will collapse. It has been found that burning process is complex and non linear so, we will use the electrical oven for distributing the temperature with the time period of 5hrs group of temperature are 100,150,200 and 250c.

Temperature increasing stage will cause using their strength properties and load carrying capacity. The purpose of this study is to understand the temperature distributions and residual strength of G.I tube encased concrete cylinders through experimental testing.

1. G.I sheet

   G.I sheet forms metallurgical bond between zinc and steel (or) iron creating a barrier to prevent itself from getting rusty as easily. It is an essential component of roofs, panel, electric appliance and machine parts.

   It satisfy the needs, we offer 3ft x 6ft, 4 x 4ft, 4 x 8ft in standard size; meanwhile we can cut the size as your request.

   1. Specification of G.I Sheet

      Thickness – 0.15mm 3.5mm

      Elongation – min 7%

      Zinc coating – 60g/m2 600g/m2

      Density – Density of G.I sheet is no

      different for mother steels and is generally taken as 7850 kg/m3

      Melting point – 1400c (Stainless steel)660c (Aluminium)

2. Hot air oven

   Fig 1.1

   Hot Air Oven offered comprise inner chambers that are made in stainless steel finish with outer structure made using mild steel in power coated finish so as to provide for longer service life standards. These hot air ovens also feature gaps between walls that come fitted with glass wool insulation so as to ensure avoiding heat loses in given applications.

   Further, the heating elements are constructed using high grade chrome plated micro-me wire with temperature controlled through thermostat usage.

   1. Technical specification

      • Inner chamber made of S.S. and outer made of Mild Steel with Power coating

      • Gap between the walls fitted with glass wool insulation to avoid heat loses

      • Heating elements are made of high grade chrome plated micro-me wire.

      • Temp. is controlled by thermostat.

      • Temp. range 50°C TO 250°C and Accuracy: +- 2°C.

      • Air Ventilation's are placed on top of both sides to remove hot gases / fumes.

      • In member Type units heaters placed at the right and left side of the inner chamber.

      • All the control switches & pilot lamps are fitted on the front panel

      • Trays should be supplied with G.I. wire mesh.

        MATERIALS

        The materials used in this experimental investigation are

        1. Cement: Ordinary Portland cement (OPC) 53Grade (IS 1489 PART I 1991).

        2. Fine aggregate: Locally Available clean river sand ZONE II of IS 383 1970.

        3. Coarse aggregate : Locally available well graded crushed Granite Coarse aggregate of normal size 20mm is used.

        4. Water : Locally available portable water obtained From source of college campus bore well is used for mixing and curing of concrete for normal conditions conforming to the requirements of water for concreting and curing as per IS: 456 2000.

        5. G.I Sheet : G.I Sheet is received from Trichy.

        METHODOLOGY

      • Concrete contains cement, water C.A and F.A. The cubes, cylinders and prism samples were cast on the mould in their required size with a water cement ratio as 0.50.

      • The cylinders were heated with different temperatures of 100ºc,150 ºc,200 ºc and 250 ºc with the time period of 5 hours for compressive strength test.

      • Sorptivity test for unsaturated concrete

RESULT AND DISCUSSION

water

water

1. sorptivity test results

   S.NO	Speci men weight	Temper ature ºC	Weight before drying in oven (kg)	Weig ht after dryin g in oven (kg)	Absorpti on of water 24 hrs (kg)
   1	CM-1	50	7.61	7.21	0.33
   2	GIS-3	50	7.81	7.20	0.26

   Comparision of

   concrete cube and GI

   Comparision of

   concrete cube and GI

   encased cube

   absorption

   0.4

   0.3

   0.2

   0.1

   0

   encased cube

   absorption

   0.4

   0.3

   0.2

   0.1

   0

   GIS

   GIS

   type of specimens

   type of specimens

   24 hrs WATER

   ABSORPTION

   CM

   24 hrs WATER

   ABSORPTION

   CM

   weight kg

   weight kg

   Sl.No	Specimens		Compressive Strength On 7 Days (N/mm2)	Compressi ve Strength On 28 Days (N/mm2)
   1	CT		13.61	20.24
   2	GICT	0.15 mm tk	20.32	29.48
   		2 mm tk	24.76	37.14

   CT

   Sl.No	Specimens		Compressive Strength On 7 Days (N/mm2)	Compressi ve Strength On 28 Days (N/mm2)
   1	13.61	20.24
   2	GICT	0.15 mm tk	20.32	29.48
   		2 mm tk	24.76	37.14

2. compressive strength of plain concrete cylinders and GI sheet encased concrete concrete cylinders

GICT-2

GICT-2

7 and 28 days strength of

CT and GICT

7 and 28 days strength of

CT and GICT

40

35

30

25

20

15

10

5

0

40

35

30

25

20

15

10

5

0

7th day

7th day

40

30

20

10

0

40

30

20

10

0

7 and 28th split tensile strength of CM and GICT

7 and 28th split tensile strength of CM and GICT

CM

GICT-0.15 GICT-2

1

CM

GICT-0.15 GICT-2

1

2

2

THICKNESS mm

THICKNESS mm

compressive strength N/mm²

compressive strength N/mm²

Comparison Of 7 and 28 days CM Compressive Strength Values vs GI sheet encased concrete cubes

7 AND 28TH DAY

40 COMPRESSIVE STRENGTH OF CM AND GICC

30

7 AND 28TH DAY

40 COMPRESSIVE STRENGTH OF CM AND GICC

30

20

10

0

CM

GICC-0.15

GICC-2

20

10

0

CM

GICC-0.15

GICC-2

THICKNESS mm

THICKNESS mm

1

1

2

2

load N/mm²

load N/mm²

Comparison Of 7 and 28 days CM Split Tensile Strength values vs GI sheet encased concrete cylinders

Comparison of 28 days Flexural Strength Values vs GI sheet encased concrete prisms

28TH DAY FLEXURAL STRENGTH OF CM AND GICP

28TH DAY FLEXURAL STRENGTH OF CM AND GICP

45

40

35

30

25

20

15

10

5

0

45

40

35

30

25

20

15

10

5

0

CM

GICP-0.15 GICP-2

CM

GICP-0.15 GICP-2

TYPE OF SPECIMEN

TYPE OF SPECIMEN

28th day

CM GICT-0.15

THICKNESS mm

28th day

CM GICT-0.15

THICKNESS mm

Comparison Of 7 days Compressive Strength Values for G.I encased concrete cylinders exposed to temperature vs GI sheet encased concrete cylinders with various thickness

7 days compressive strength of

GICT exposed to temperature

40

35

30

25

20

GICT-0.15

15

7 DAYS COMPRESSIVE STRENGTH OF CMT AND GICT

40

30

7 days compressive strength of

GICT exposed to temperature

40

35

30

25

20

GICT-0.15

15

7 DAYS COMPRESSIVE STRENGTH OF CMT AND GICT

40

30

10

5

0

10

5

0

GICT-2

GICT-2

0 100 150 200 250

temperature °C

0 100 150 200 250

temperature °C

20

10

0

20

10

0

CMT GICT-0.15

GICT-2

CMT GICT-0.15

GICT-2

100 150 200 250

temperature °C

100 150 200 250

temperature °C

compressive strength N/mm²

compressive strength N/mm²

compressive strength N/mm²

compressive strength N/mm²

e

e

Comparison Of 28days Compressive Strength Values for G.I encased concrete cylinders exposed to temperature vs GI sheet encased concrete cylinders with various thickness

28 days compressive strength of

GICT exposed to temperature

40

30

28 days compressive strength of

GICT exposed to temperature

40

30

0 100 150 200 250

temperature °C

0 100 150 200 250

temperature °C

20

10

20

10

GICT-0.15

GICT-2

GICT-0.15

GICT-2

0

0

20

10

0

20

10

0

CMT GICT-0.15

GICT-2

CMT GICT-0.15

GICT-2

Comparison Of 7days Compressive Strength Values for G.I encased concrete cylinders exposed to temperature vs plain concrete cylinders after temperature

Comparison Of 28days Compressive Strength Values for G.I encased concrete cylinders exposed to temperature vs plain concrete cylinders after temperature

28 DAYS COMPRESSIVE STRENGTH OF CMT AND GICT

40

30

28 DAYS COMPRESSIVE STRENGTH OF CMT AND GICT

40

30

100 150 200 250

temperature °C

100 150 200 250

temperature °C

CONCLUSION

• G.I sheet encased cylinders gives more strength compared to the normal cylinders.

• It does not need any plastering. It gives the good appearance.

• The concrete cylinder has an encasing of G.I sheet of thickness 0.15mm and 2mm its strength tested.

• There is an increase of 43.5% is the compressive strength in heated condition.

REFERENCE

1. Chiang, Chih-Hung and Tsai, Cho-Liang, Time-Temperature Analysis ofBond Strength of a Rebar after Fire Exposure, cement and concrete research, V.33,No.10,Oct.2003 pp 1651-1654.

2. Neville, A.M., properties of concrete,4th edition, Pearson education Limited.1995,844 pp.

3. Abrams, M.S., Compressive Strength of Concrete at Temperatures to 1600 F,Temperature and Concrete,SP25, American Concrete Institute,farmingtonhills,MI,1971,pp.33-58.

4. National Codes and Standards Council of the Concrete and Masonry Industries, Assessing the condition and repair alternatives of fire- Exposed concrete and masonry members, fire protection planning report, Aug.1994, 14

5. Yüzer N., Aköz , F and Öztürk, L.D., Compressive StrengthColor Change Relation in Mortar sat high temperature, Cement and Concrete Research,V.34,No.10, Oct.2004, pp.1803-1807.