Mechanical Properties Of Fibre Reinforced Concrete Subjected To Elevated Temperature

R.C.Rajkiran et al., International Journal of Advanced Research in Innovative Discoveries in Engineering and Applications[IJARIDEA] Vol.2, Issue 2,27 April 2017, pg. 39-46

Mechanical Properties Of Fibre Reinforced Concrete Subjected To Elevated Temperature R.C.Rajkiran1, D.Gunasekaran2, S.M.Mathana vigneshwar3, S.Maharaja4 1,2,3.4

Kalasalingam Academy Of Research And Education, Kalasalingam University, Krishnankoil-626 126 1 rajkiran.raj07@gmail.com, 2dgsekar.sathish31@gmail.com, 3vigneshmathan1996@gmail.com , 4 maha25081995@gmail.com

Abstract— The impact of high temperature on the break property of solidified cements which are strengthened with steel and polypropylene filaments have been explored inside the extent of this review. Test comes about demonstrates that higher temperature brings about lessening quality in both the filaments however with a variety in the most extreme temperature. Steel fiber strengthened cement and polypropylene fiber fortified cement is a cementitious material fortified with a given substance of discrete strands. The better mechanical property makes these filaments critical in building development and has expanded use fundamentally in view of its vitality assimilation limit. The vitality required to haul out the strands from the broke cement is more than the vitality required to split the solid grid. Hence, the vitality ingestion limit is the primary material property profited by fiber fortifications. Be that as it may, this vitality retention property holds great just up to a specific temperature. This consider was examined the present work keeping in mind the end goal to evaluate the ideal temperature up to which the quality of the solid filaments would be most extreme.

Keywords— Compressive Strength, High Temperature, Steel Fibre, Polypropylene Fibre.

I. INTRODUCTION

In Present days the utilization of high quality cement is expanded definitely and this is made conceivable with the assistance of fortifications like steel strands, polypropylene filaments, geopolymers and so on.

These fortifications have an immediate increment in the quality of the solid lattice. At the point when these fiber strengthened cements are subjected to high temperatures they won't act of course. The conduct of cement at lifted temperatures relies on upon length of introduction, rate of temperature rise, level of water immersion of the solid, age of the solid, sort of total utilized, kind of bond utilized, total/concrete proportion. In this review the adjustment in the properties of fiber fortified cement under various temperatures and furthermore the most extreme temperature till the solid can withstand is talked about.

Concrete seems to maintain no apparent harm when presented to temperatures up to 400 degrees Fahrenheit. In the event that temperatures over 400 °F are to be experienced, it is insightful to examine the presentation conditions and the solid which will be utilized. To get some thought of a run of the mill progression of impacts as temperature rises, our research center review is directed with two distinctive cement blends with steel strands and polypropylene filaments. The solid blocks are put in stove and warmed for 60 minutes with changing temperatures from 100 °C to 800 °C, and the 3D shapes are tried for compressive quality and the diagram amongst temperature and quality could tell the greatest temperature the solid could withstand. [5] proposed a principle in which another NN yield input control law was created for an under incited quad rotor UAV which uses the regular limitations of the under incited framework to create virtual control contributions to ensure the UAV tracks a craved direction. Utilizing the versatile back venturing method, every one of the six DOF are effectively followed utilizing just four control inputs while within the sight of un demonstrated flow and limited unsettling influences. © 2017, IJARIDEA All Rights Reserved

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R.C.Rajkiran et al., International Journal of Advanced Research in Innovative Discoveries in Engineering and Applications[IJARIDEA] Vol.2, Issue 2,27 April 2017, pg. 39-46

II. OVERVIEW OF THE PROPOSED SCHEME

Materials Used: In this review we have utilized polypropylene filaments and steel strands as strengthening materials to the solid grid. The bond we utilized is conventional Portland concrete of 53 review

A.

Physical properties of Materials: Bond: OPC 53 review bond is utilized, fitting in with IS 12269-1987. Bond particular gravity is observed to be 3.15 utilizing pyconometer. Utilizing Vicat contraption consistency, introductory and last setting time is discovered which 32%, 30 and 260 minutes separately are.

Fine and Coarse total: The stream sand and pounded stones is utilized as fine total and coarse totals separately.

With the strainer size of 2.36 microns the fine totals are sieved though coarse total in 12mm sifter. The particular gravity with the assistance of pyconometer is found for both fine and coarse totals which are 2.65 and 2.70 individually.

Water and Admixture: A decent nature of water is utilized and the water/concrete proportion utilized is 0.35.

Since low w/c proportion is utilized 1% hyper plasticizer is utilized as admixture. The blend proportion according to configuration is 1:1.4:2.3.

Polypropylene filaments: Polypropylene is a manufactured hydrocarbon polymer; the fiber is made utilizing expulsion forms by hot drawing the material through the pass on. The pp fiber length is 30 mm and 0.5 mm breadth; thus perspective proportion will be 60. The thickness of the polypropylene fiber utilized is 900 kg/cum. As the fiber has low particular gravity its weight is 0.15% of the aggregate weight of cement utilized.

B.

The benefits of polypropylene filaments: • Increase in pliable and flexural quality.

• Reduction in plastic shrinkage breaking.

• Minimizing warm breaking.

• Improved spalling resistance.

Fig.1. Polypropylene fibre

Steel fibres: Steel fibre is made up of steel and has a density of 7900 kg/cum. The diameter of the steel fibre used is about 0.60 mm which is a hook end fibre. Length of this fibre used is 35 mm and © 2017, IJARIDEA All Rights Reserved

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R.C.Rajkiran et al., International Journal of Advanced Research in Innovative Discoveries in Engineering and Applications[IJARIDEA] Vol.2, Issue 2,27 April 2017, pg. 39-46

hence the aspect ratio (L/D) is 55. The weight of steel fibre used is 1% to the total volume of the concrete mix.

The advantages of steel fibre reinforcement: • High performance and improved crack resistance • Multidirectional reinforcement.

• Less labor and less construction time required.

• Steel fibres reduce the permeability and water migration in concrete.

Fig.2. Round hooked end fibre

Fig.3. Casted Polypropylene fibre cube

Fig.4. Cube in heated Muffle furnace

Fig.5. Steel fibre cube after testing

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R.C.Rajkiran et al., International Journal of Advanced Research in Innovative Discoveries in Engineering and Applications[IJARIDEA] Vol.2, Issue 2,27 April 2017, pg. 39-46

Fig.6. Polypropylene fibre cube after testing

III. EXPERIMENTAL PROCEDURE

The blend configuration depends on the idea of applied blend plan and the blend proportion is resolved as 1:1.4:2.3 with 0.35 w/c proportion. The materials are gathered according to the proportion. At that point for steel fiber 3D square throwing 1% the heaviness of the solid blend is weighed and is blended with the bond and totals though for polypropylene strands 0.15% of the heaviness of the solid blend is utilized. At that point the solid is then threw in 100 mm x 100 mm x 100 mm 3D squares. Taking into account setting of cement for a day the shapes are demoulded and are kept in curing water for 28 days. On the 28th day the 3D shapes are removed from the curing tank and are made to dry. Following a hour the heaviness of the air dried 3D shape test is noted and is then kept inside a stifle heater with temperature set to 100°C for 60 minutes 60 minutes. At that point the heater is turned off and the specimen is left inside the heater undisturbed for 24 hours. Following day the 3D shape is then tried to decide the compressive quality. The same is rehashed for various temperatures of 200°C, 300°C, till 800°C and the individual compressive quality of the solid shape are found.

TABLE I COMPRESSIVE STRENGTH AT DIFFERENT TEMPERATURES

STEEL FIBRES TEMP (°C)

100 200 300 400 500 600 700 800

Weight before heating (grams) 2541.5 2495.5 2466.5 2505.5 2561 2543 2534 2472

Weight after heating (grams) 2508 2398 2353.5 2390.5 2430 2406 2395 2302

POLYPROPYLENE FIBRES Weight Weight before after heating heating (grams) (grams) 2531 2499 2512.5 2476 2557.5 2459 2584 2465.5 2470 2355 2652 2521 2610 2505 2562 2447

COMPRESSIVE STRENGTH Steel fibre Polypropylene (MPa) fibre (MPa) 29 35.8 48.2 63.4 37.5 30.5 25.6 23.3

31.1 43.9 57.7 44.3 37.7 29 31.2 29.8

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R.C.Rajkiran et al., International Journal of Advanced Research in Innovative Discoveries in Engineering and Applications[IJARIDEA] Vol.2, Issue 2,27 April 2017, pg. 39-46

Fig.7. Compressive strength of fibres at different temperatures

IV. RESULTS AND DISCUSSION

Arrangement for diminishing in compressive quality and rate misfortune in weight are ascertained and individual charts are plotted. From figure 3 unmistakably the quality of steel fiber is most extreme at 400 °C and for polypropylene fiber is at 300 °C. So the rate misfortune in the compressive quality of the filaments are ascertained past the most extreme temperatures of the separate strands and is plotted. The rate misfortune in weight is taken as ordinate and temperature in abscissa and weight reduction is plotted for both the strands.

TABLE II PERCENTAGE LOSS IN WEIGHTS TEMPERATURE (°C)

STEEL FIBRES

POLYPROPYLENE FIBRES

100

1.32

1.26

200

3.91

1.45

300

4.58

3.85

400

4.59

4.59

500

5.12

4.66

600

5.39

4.94

700

5.49

4.02

800

6.88

4.49

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R.C.Rajkiran et al., International Journal of Advanced Research in Innovative Discoveries in Engineering and Applications[IJARIDEA] Vol.2, Issue 2,27 April 2017, pg. 39-46

Fig.8. Weight of steel fibre before and after heating

Fig.9. Weight of polypropylene fibre before and after heating

Fig.10. Percentage loss of weight in fibres

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R.C.Rajkiran et al., International Journal of Advanced Research in Innovative Discoveries in Engineering and Applications[IJARIDEA] Vol.2, Issue 2,27 April 2017, pg. 39-46

TABLE III PERCENTAGE LOSS IN COMPRESSIVE STRENGTHS TEMPERATURE (°C)

STEEL FIBRES

POLYPROPYLENE FIBRES

100

0

0

200

0

0

300

0

0

400

0

23.22

500

40.85

34.66

600

51.89

49.74

700

59.62

45.93

800

63.25

48.35

Fig.11. Percentage loss of compressive strength in fibres

V. CONCLUSION From the results and discussions the following conclusions are made regarding behavior of fibre reinforced concrete at elevated temperatures.

1.The steel fibre should not be used in places above 400°C as it started to decrease in strength after the optimum temperature.

2.For the polypropylene fibres the maximum allowable temperature for good functioning is about 300°C. 3.From figure 6 it is inferred that the polypropylene fibre melts but they fills up the voids so that the weight loss is less when compared to steel fibres.

4.From table 1 it is clear that the compressive strength of polypropylene fibre is more than that of the steel fibres in most of the cases.

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R.C.Rajkiran et al., International Journal of Advanced Research in Innovative Discoveries in Engineering and Applications[IJARIDEA] Vol.2, Issue 2,27 April 2017, pg. 39-46

5.The percentage loss of the compressive strength (figure 6) clearly proves that even though the polypropylene fibres starts to melt before the steel fibres its fracture properties is good than that of steel fibres at higher temperatures.

ACKNOWLEDGMENT

We express our sincere thanks to our chancellor Dr.K.Sridharan, for all the facilities provided by him for completion of this project work.

We would like to express our gratitude to our Director Dr. S.Sasi Anand, for his kind cooperation in this study.

Our sincere thanks to the Head of our Department Dr.M.Muthukannan, without him this project could not have been this much successful; he also encouraged and guided us throughout our experimental study.

REFERENCES [1] Amit Rana, “Some Studies on Steel Fiber Reinforced Concrete”, International Journal of Emerging Technology and Advanced Engineering Vol. 3, Issue 1.

[2] Saeed Ahmed et.al, “A Study on Properties of Polypropylene Fiber Reinforced Concrete” , 31st Conference on our World in Concrete & Structures.

[3] M. L. Malhotra, “The Effect of Temperature on the Compressive Strength of Concrete”, Magazine Concrete Research, Vol. 8, No. 23; pp. 85 ff.

[4] Farhad Aslani, Bijan Samali, “Constitutive relationships for steel fibre concrete at elevated temperature”, fire technology, Springer science, 50, 1249-1268.

[5] Christo Ananth,"A NOVEL NN OUTPUT FEEDBACK CONTROL LAW FOR QUAD ROTOR UAV",International Journal of Advanced Research in Innovative Discoveries in Engineering and Applications[IJARIDEA],Volume 2,Issue 1,February 2017,pp:18-26.

[6] P.H. Petersen, “Resistance to High Temperature”, A.S.T.M. Special Technical Publication, No. 169-A; pp.

290 ff.

[7] W. Khaliq, “Performance characterization of high performance concretes under fire conditions (Ph.D. thesis), Michigan State University, 2012 [8] T.T. Lie and V.R. Kodur,”Thermal properties of fibre reinforced concrete at elevated temperatures”, IR 683, IRC, National Research Council of Canada, Ottawa, Canada,1995.

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