Project Report

MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

1. INTRODUCTION

INTRODUCTION Concrete is a brittle material with low tensile strength and low strain capacity that result in low resistance to cracking. To improve such properties, fibre reinforced concrete (FRC) has been developed (4). Fibres are intended to improve tensile strength, flexural strength, toughness and impact strength (2), to change failure mode by means of improving post-cracking ductility, and to control cracking (3). Tensile strength of the composite, related more to the stress at which matrix develops a macro-crack, will not differ much for most conventional fibre reinforced cementitious materials. Several fibre materials in various sizes and shapes have been developed for use in FRC. Among these fibres, the polypropylene has been one of the most successful commercial applications. The common forms of these fibres are smooth-monofilament and have triangular shape. Polypropylene fibres have some unique properties that make them suitable for reinforcement in concrete. The fibres have a low density, are chemically inert and non corrosive. The primary objectives of this investigation were to determine the benefits of using polypropylene fibre reinforced concrete (PFRC). • To determine the properties of the fresh concrete mixtures using fiber. • To investigate and compare the properties of hardened concrete for control and various PFRC mixes. • Observe the difference between failure patterns of plain and PFRC specimens.:

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

2. LITERATURE REVIEW

2.1 Structural Behaviour of Fibrous Concrete Using Polypropylene Fibres Parveen, AnkitSharma[2]

The aim of the study was to investigate the effect of variation of polypropylene fibres ranging from 0 % to 2.0 % on the behaviour of fibrous concrete.

Conclusions

The result showed that addition of polypropylene fibre has a little effect on the compressive strength, but there was significant increase in the tensile strength with increase in fibre volume fraction. The investigation shows an increase of 47% of split tensile strength and 50% of flexural strength. The result showed that ultimate load mainly depended on percentage volume fraction of fibre. The results shows that split tensile strength increases with increase in fibre volume fraction, because of the holding capacity of the fibres which helps in preventing the splitting of concrete. Polypropylene fibre reinforced concrete showed increase in flexural strength when compared with reinforced concrete.[2]

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

2.2 Effect of polypropylene fibres on strength characteristics of fly ash Concrete Dhillon, Ramandeep, Sharma, Shruti and Kaur, Gurbir[3

The Polypropylene fibres have been used in percentages of 0 % and2.0 % by volume.Effect of varying percentages of Polypropylene fibres on the compressive strength, split tensile strength and flexural strength of concrete has been studied. M20 concrete mix was designed using IS 10262:2009.The compressive strength test, flexural strength test and split tensile strength test is carried out for 7 days and 28 days.

Conclusions

Test results indicate with the increase in percentage of polypropylene fibre content, the compressive strength, split tensile strength and flexural strength of concrete increases by the use of fibers in concrete. The addition of fibres in concrete by volume ( 0 and 2.0 per cent) increases the compressive strength of PPF concrete at both 7 and 28 days. Similar is the case with split tensile strength of cylinder and flexural strength of beam.

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

2.3 Experimental Investigation on Hybrid Fiber Reinforced Concrete Vikrant S. Vairagade, Kavita S. Kene[4]

The use of fibers in a suitable combination may potentially improve the overall properties of concrete.The effect of fibers, is investigated in this paper for a M25 grade concrete.Control and fiber

hybrid

composites

were

cast

using

different

fiber

proportions

of

polypropylene.Compressive test and split tensile strength were performed and results were extensively analyzed to associated with above fiber proportions. Slump tests were carried out to determine the workability and consistency of fresh concrete.For compressive strength test, both cube specimens of dimensions 150 x 150 x 150 mm were cast for M25 grade of concrete. The moulds were filled with 0% HFRC SO.5P0.5, HFRC SO.6P0.4, HFRC SO.7P0.3 and HFRC SO.8P0.2 fibers. For tensile strength test, cylinder specimens of dimension 150 mm diameter and 300 mm length were casted.

Conclusion S0.8P0.2 Gives High Strength as Compare to other Combination.[4]

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

2.4 Evaluation Of Mechanical Properties For Polypropylene Reinforced Concrete Abhishek Kumar Singh, Anshul Jain and DeependraSingh[6]

The effect of inclusion of polypropylene on the compressive and flexure properties of fiber reinforced concrete was studied. Concrete mixtures consists of varying percentage of polypropylene fibers ranging from 0% to 1.8 % by volume of concrete.

Conclusions

Compressive strength of material increases with increasing fiber content. Compressive strength was found out to be maximum for a mix of 0.3% PP and 1% SF.The flexural strength increases with increase in fiber content.The maximum increase in flexural strength was found to be around 43 % .[6]

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

2.5 Development and Application of Hybrid Fibre Reinforced Concrete MarijanSkazlić[7]

The main aim of the investigations was to determine the optimum composition in terms of flexural behaviour of fibre-reinforced concrete containing polypropylene fibres. The research was conducted on 12 fibre-reinforced concrete mixtures. The maximum aggregate grain size was 16 mm. ten different concrete mixtures were prepared with various combinations of polypropylene.All the mixtures had the same water/cement ratio of 0.41, and the same workability in fresh state.

Conclusions

On the basis of the research conducted, it was determined that hybrid fibre-reinforced concretes have significantly higher values of compressive and flexural strengths, and split tensile strength in comparison with fibre-reinforced concretes containing polypropylene fibres.The research indicated that polypropylene fibres can be effectively used to optimize the behavior of concrete in fresh and hardened states.An analysis of the test results showed that polypropylene fibres are effective in crack reduction in young concrete due to their lower modulus of elasticity.

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

3. MATERIALS 3.1 Cement: Ordinary Portland cement 53 grade conforming to IS: 8112-1939 was used. Its properties are shown in table below Table 3.1.1: Cement test results[7]

Sl.no

Characters

Experimental As per Is:8112 1989

1.

Consistency of cement 34%

2.

Specific gravity

3.10

3.15

3.

Initial setting time

50mins

>30min

4.

Final setting time

230mins

<600mins

5.

Compressive strength 3days

23.5N/mm2

>23

7days

35.8N/mm2

>33

Fineness of cement

1.2%

10%

6.

-

3.2 Fine aggregate Table 3.2.1 Physical properties of Fine Aggregate Natural and conforming to zone 2 1 Specific gravity

2.71

2 Fineness modulus

2.63

3 Bulk density in loose condition

1.8 g/cc

4 Bulk density in compacted condition

1.97 g/cc

5 Water absorption

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1.4 %

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

Table 3.2.2 Sieve analysis test results of fine aggregate

Sieve

Cumulative %

Values as per

size

passing

Indian

for sand

Standards

4.75 mm

95.1424

90-100

2.36 mm

90.285

75-100

1.18 mm

72.777

55-90

600 µ

43.631

35-59

300 µ

4.467

8-30

150 µ

0.06

0-10

Pan

-

0-10

3.3 Coarse aggregate Table 3.3.1 Physical properties of Coarse Aggregate

1 Specific gravity

2.8

2 Bulk density in loose condition

1.1 g/cc

3 Bulk density in compacted condition

1.59 g/cc

4 Water absorption

1.1 %

Table 3.3.2: Sieve analysis results of 20 mm downsize aggregate

Sieve size % passing finer IS standard values 40 mm

100

100

20 mm

61.62

95-100

12.5 mm

3.04

-

10 mm

1.02

25-55

4.75 mm

0

0-10

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

Table 3.3.3: Sieve analysis results of 20 mm downsize aggregate

Sieve size % passing finer IS standard values 40 mm

100

-

20 mm

100

100

12.5 mm

96.97

90-100

10 mm

88.89

40-85

4.75 mm

2.03

0-10

Proportioning of 20 mm and 12.5 mm coarse aggregate fraction Different proportions of 20 mm and 12.5 mm are tried to obtain well graded coarse aggregate . For 40-60 proportion of 20 mm and 12.5 mm the aggregate were found to be graded . Hence 40-60 proportion of 20 mm and 12.5 mm fraction by mass of concrete aggregate is finalized for casting.

Table 3.3.4: Sieve analysis of 40:60 % of 20 mm and 12.5 mm coarse aggregate

Sl no IS sieve size

% passing finer

Total % passing IS standard Values

20 mm 12.5 mm (40%)

(60%)

1

40

40

60

100

100

2

20

24.648

60

84.65

95-100

3

12.5

1.216

58.18

59.40

-

4

10

0.408

53.33

53.74

25-55

5

4.75

0.004

1.218

1.222

0-10

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

3.4 Water Water used for both mixing and curing should be free from injurious amount of deleterious material. Potable water is generally considered satisfactorily for mixing and curing concrete. In present work potable water is used.

3.5 Polypropylene fibres Table 3.5.1 Properties of Polypropylene Fibres

Diameter

0.20 mm

Length

12 mm

Aspect Ratio

60

Density

1400 kg/m3

Modulus Of Elasticity

1300-1800 MPa

Figure 3.5.1

4.OBJECTIVES OF PROJECT 4.1Objectives 1. To study the workability of the concrete by using different proportions of polypropylene. . 2. To evaluate compressive strength of concrete by using different proportions of polypropylene.

3. To evaluate the split tensile strength of concrete by using different proportions of polypropylene.

4. To evaluate flexural strength of concrete by using different proportions of polypropylene. DEPARTMENT OF CIVIL ENGINEERING KBN COLLEGE OF ENGINEERING, KLABURAGI

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

5. MIX DESIGN 5.1 Mix design for M20 grade[10]

A-1 Stipulation for proportioning Grade designation =M20 Maximum nominal size of aggregate =20 mm & 12.5 mm Workability =75-100 mm slump Degree of supervision =Good Type of aggregate =crushed angular aggregate

A-2 Test data for materials Cement used - Ultra tech OPC 53 grade Specific gravity of cement - 3.10 Specific gravity of coarse aggregate - 2.8 Specific gravity of fine aggregate - 2.71 Water absorption of coarse aggregate - 1.10 % Water absorption of fine aggregate – 1.40 % Fine aggregate conforming to grading zone 2 of table 4 of IS 383

A-3 Target strength for mix proportioning f'ck=fck+1.65S Where f'ck=target average compressive strength at 28 days, fck=characteristic compressive strength at 28 days, S=standard deviation From table 1 of IS 10262-2009, S=4 N/mm2 f'ck = 20 + ( 1.65 × 4 ) f'ck= 26.6 N/mm2

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

A-4 Selection of water cement ratio From table 5 of IS 456, maximum water cement ratio for M20 and severe condition =0.55 Adopt w/c ratio =0.55

A-5 Selection of water content From table 2 of IS 10262 2009 Maximum water content for 20 mm aggregate =186 liters (for 25-50 mm slump) 6 percent increase for desired 75-100 mm slump range Estimated water content =1.06×186=197.16 liters

A-6 Calculation of cement content W/C ratio=0.55 Cement content =197.16/0.55=358.47 kg/m3 From table 5 of IS 456, minimum cement content for severe exposure conditions =300 kg/m3 358.47 kg/m3 > 300 kg/m3 Hence ok

A-7 Proportioning of volume of coarse and fine aggregate From table 3 of IS 10262 2009, volume of coarse aggregate corresponding to 20mm down size aggregate and fine aggregate conforming to grading of zone 2 =0.62 for w/c ratio of 0.50, for w/c of .55 corrected volume of coarse aggregate is 0.61. Therefore volume of fine aggregate =1-0.61=0.39

A-8 Mix calculations Volume of concrete =1m3 Volume of cement = (mass of cement /specific gravity) ×10-3 = (358.47/3.10)×10-3 = 0.1156 m3 Volume of water = (mass of water /specific gravity) ×10-3 = (197.16/1) ×10-3 = 0.197 m3 DEPARTMENT OF CIVIL ENGINEERING KBN COLLEGE OF ENGINEERING, KLABURAGI

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

Volume of all in aggregate = 1 - ( 0.1156 + 0.197 ) e = 0.6874 m3 Mass of coarse aggregate = e × volume of ca×specific gravity × 1000 = 0.6874 × 0.61 × 2.8 × 10000 = 1174.0792 kg/m3 Mass of fine aggregate

= e × volume of fa×specific gravity × 1000 = 0.6874 × 0.39× 2.71 × 1000 = 726.51 kg/m3

Field Corrections Absorptions by F.A

= ((1.4*726.51)/100) = 10.17 litres

Absorptions by C.A

= ((1.10*1174.0792)/100) = 12.91 litres

Actual weight of C.A

= 1174.0792 – 12.91 = 1161.1692 kg/m3

Actual weight of F.A

= 726.51 – 10.17 = 716.34 kg/m3

Actual amount of water = 197.16 + 10.17 + 12.91 = 220.24 litres .

Mix proportions per cubic meter of concrete becomes

Water

Cement

Fine aggregate

Coarse aggregate

0.61

1

2.026

3.27

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

5.2 Material calculations (M20) M20 grade cube For one cube: - 0.15m×0.15m×0.15m Wet volume = 0.15×0.15×0.15 = 0.003375 m3 Weight of one cube = 0.003375×2456.21 = 8.2897 kg Adding 10 % for wastage Weight = 1.1 * 8.2897 = 9.1186 kg Cement = weight/sum of mix proportions = 9.1186/(0.61+1+2.026+3.27) = 1.32 kg Fine aggregate = 1.32 × 2.026 = 2.674 kg Coarse aggregate = 1.32 × 3.27 = 4.316 kg Water = 1.32 × 0.61 = 0.8052 kg

M20 grade cylinder For one cylinder =150mm dia×300mm length Volume = Area×length =(π/4)×d2 ×h =(π/4)×0.152×0.3 Wet volume = 0.0053 m3 Weight of one cylinder = 0.0053×2456.21 = 13.01 kg Adding 10 % for wastage Weight = 1.1 * 13.01 = 14.311 kg Cement = weight/sum of mix proportions = 14.311/(0.61+1+2.026+3.27) = 2.072 kg Fine aggregate= 2.072 × 2.026 = 4.197 kg Coarse aggregate= 2.072 × 3.27 = 6.77 kg Water = 2.072 × 0.61 = 1.2639 kg

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

M20 grade prism 1 prism = 0.1mm × 0.1mm ×0.5 mm Wet volume = 0.1 × 0.1 × 0.5 = 0.005 m3 Weight of one prism = 0.005 ×2456.21 = 12.28 kg Adding 10 % for wastage Weight = 1.1 * 12.28 = 13.508 kg Cement = weight/sum of mix proportions = 13.508/(0.61+1+2.026+3.27) = 1.955 kg Fine aggregate= 1.955 ×2.026 = 3.96 kg Coarse aggregate= 1.955 × 3.27 = 6.392 kg Water = 1.955 × 0.61 = 1.192 kg

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

6. EXPERIMENTAL PROGRAM:

6.1 Details of various mixes MIX

Percentage of Polypropylene fibre ( % )

MIX 1

0

MIX2

0.5

MIX3

1.0

MIX4

1.5

MIX5

2.0

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

6.2 Workability Test[14] Workability is carried out by conducting the slump test[11] and compaction factor[12] test as ishown in Figures.

Slump = h2-h1 h1 = height before removing cone in mm. h2 = height after removing cone in mm.

compaction factor =

𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑝𝑎𝑟𝑡𝑖𝑎𝑙𝑙𝑦 𝑐𝑜𝑚𝑝𝑎𝑐𝑡𝑒𝑑 𝑐𝑜𝑛𝑐𝑟𝑒𝑡𝑒 𝑤𝑒𝑖𝑔ℎ𝑡 𝑜𝑓 𝑓𝑢𝑙𝑙𝑦 𝑐𝑜𝑚𝑝𝑎𝑐𝑡𝑒𝑑 𝑐𝑜𝑛𝑐𝑟𝑒𝑡𝑒

Figure 6.2.1

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Figure 6.2.2

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

6.3 Preparation and casting of test specimens: For both M20 grade of concrete, 150mm concrete cubes were casted for compressive strength, 150x300mm cylinders for splitting tensile strength and 100x100x500mm beams for flexural strength. The fibers are added by volume of concrete. After casting, all the test specimens were finished with a steel trowel. All the test specimens is stored. They are demoulded after 24 hours, and were put into a water curing tank (figure6.3.1) for 28 days of curing[13].

Figure6.3.1

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

6.4 Compressive strength test[13] : Cube specimens were used for determining characteristic compressive strength. The cubes were tested in a compression testing machine of capacity 200Ton. The cubes were placed and the load was applied in the testing setup such that the top surface of the cube during casting was perpendicular to the two opposite sides of the compressed surfaces. The load at which specimen ultimately failed was noted. The compressive strength was calculated by dividing the load by area of specimen compressive strength (Fc) =ultimate load /cs area of cube

.

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

Figure 6.4.1

6.5 Split tensile strength[13] Test: The tensile strength of concrete is obtained indirectly by subjecting concrete cylinders to the action of a compressive force along two opposite generators.. The cylinder split tensile test of Brazilian test is a good method for subjecting a large part of the cross section of a specimen to uniform tensile stresses. The tensile strength of concrete was calculated by using the formula Split tensile strength=2P/(πDL)

Where D= diameter of the cylinder in mm. L= height of the cylinder in mm. P= load in ton.

Figure 6.5.1

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

6.6 Flexural strength[13] Test Another common test performed for determination of tensile strength is flexure test, in which a simple plain concrete prism of 100x100x500mm and the load is applied at L/3 from each end.The load at which specimen fails is noted. Flexural strength[15]=Pl/(bd2) Where P=load in KN l=length of the prism=500mm d=depth of prism=100mm b=width of prism=100mm

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

7. RESULTS AND DISCUSSION 7.1 Results of workability for M20 Grade Table 7.1.1 Mix

Slump value Compaction factor In mm

Mix 1

96

0.940

Mix 2

99.5

0.947

Mix 3

75

0.779

Mix 4

80

0.790

MIX 5 76

0.723

M20

M20

150 100 Slump value In mm

50

1 0.8 0.6 0.4 0.2 0

0 Mix 1 Mix 2 Mix 3 Mix 4

Compaction factor Mix Mix Mix Mix 1 2 3 4

Discussion for M20 Grade Figure 7.1.1 shows the graph of slump value vs Mix proportions for M20 grade of concrete. As the percentage of polypropylene is decreased, the workability is found to be increasing. Figure7.1.2 shows the graph of compaction factor vs Mixproportions.Similar results are observed by conducting compaction factor test.

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

7.3 Results of Compressive strength test for M20 grade. Table for 7.3.1 Mix

Load in KN

Average load in KN

Compressive stress (N/mm2)

578.79 Mix 1

613.125

577.155

25.651

554.265

24.634

631.077

28.048

676.89

30.084

694.066

32.054

539.55 549.36 Mix 2

544.455 568.98 647.46

Mix 3

632.745 613.125 667.08

Mix 4

706.32 657.27

MIX 5

657.27 722.82 702.11

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

M 20 grade 35

30

25

20 Compressive stress (N/mm2)

15

10

5

0 Mix 1

Mix 2

Mix 3

Mix 4

Discussion for M20 Figure 7.3.1 shows the graph of compressive strength vs Mix proportions for M20 grade of concrete. The compressive strength of Mix1 is found to be more than Mix2 .The maximum improvement in compressive strength is seen in M5.

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

7.5 Results of Split tensile test for M20 grade. Table 7.5.1 Mix

Load in KN Average load in KN Split

Tensile

Strength

(N/mm2) 264.87 Mix 1

279.585

273.012

3.862

255.06

3.608

309.015

4.372

338.445

4.788

274.68 250.155 Mix 2

264.87 250.155 323.73

Mix 3

299.205 304.11 343.35

Mix 4

333.54 338.445

MIX

322.02

5

308.53

319.40

4.524

327.67

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

M 20 grade) 6

5

4

3

Split Tensile Strength (N/mm2)

2

1

0 Mix 1

Mix 2

Mix 3

Mix 4

Discussion for M20 Figure 7.5.1 shows the graph of split tensile strength vs Mix proportions for M20 grade of concrete. The split tensile strength of Mix1 is found to be more than Mix2 .The maximum improvement in split tensile strength is seen in M5.

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

7.7 Results of Flexural test for M20 grade. Table 7.7.1 Mix

Load in KN Average load in KN flexural

Strength

(N/mm2) 6.621 Mix

7.112

1

5.886

6.543

3.2716

6.131

3.0656

8.338

4.16925

8.583

4.29875

6.131 Mix

6.621

2

5.640 8.093

Mix

8.829

3

8.093 8.338

Mix

8.338

4

9.074

Mix 5

9.702 9.876 10.351

9.976

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4.8967

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

M20 grade 5 4.5 4 3.5 3 2.5 flexural Strength (N/mm2) 2 1.5 1

0.5 0 Mix 1

Mix 2

Mix 3

Mix 4

Discussion for M20 Figure 7.7.1 shows the graph of flexural strengthvs Mix proportions for M20 grade of concrete. The flexural strength of Mix1 is found to be more than Mix2 .The maximum improvement in flexural strength is seen in M5.

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

8. CONCLUSIONS 1. As the percentage of polypropylene is increased from 0% to 2.0% there is increase in compressive, split tensile & flexural strength for M20 grade.. • Polypropylene fibres dose not disperse properly in the mixing water. Addition of fibres to dry mix was found to be more practical. • The presence of fibres in concrete alerts the failure mode of material. It is found that the failure mode of plain concrete is mainly due to spalling, while the failure mode of fibre concrete is bulging in transverse directions. • Compressive strength of material increases with increasing fibre content. Strength enhancement ranges from 8% to 16% for PFRC. • Strength enhancement in splitting tensile strength due to polypropylene fibre addition varies from 5% to 23%. Split tensile strength at 28’days is approximately 50% higher than 7 day’s strength. • During the test it was visually observed that the PFRC specimen has grater crack control as demonstrated by reduction in crack widths and crack spacing. The flexural strength increases with increasing fibre content. The maximum increase in flexural strength of PFRC is 36%. • The percentage increase in shear strength of the polypropylene fibre mix varies from 23% to 47%. This is because of fibres enhances the load carrying capacity of mix.

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

8.1 SCOPE OF FURTHER STUDY 1. The investigation can be done for different grades of concrete such as M25, M30, M35,M40 etc., and also on high strength concrete. 2. The investigation can be done by varying percentages of fly ash with addition of hybrid fbres. 3. The effect of concrete with addition of other types of fibres such as glass fibre, nylon fibre, bamboo fibre etc., can be studied. 4. The effect of concrete using other pozzolanic materials with addition of hybrid fibres can be studied.

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

REFERENCES 1)Muntadher Ali Challoob, VikasSrivastava(Effect of Fly Ash and Steel Fibre on Portland Pozzolana Cement Concrete)International Journal of Engineering Trends and Technology (IJETT) – volume 5 number 3 - Nov 2013.

2)

Parveen ,Ankit Sharma(Structural Behaviour of Fibrous Concrete Using Polypropylene

Fibres)

International Journal of Modern Engineering Research (IJMER) www.ijmer.com

Vol.3, Issue.3, May-June. 2013 pp-1279-1282 ISSN: 2249-6645.

3) Dhillon, Ramandeep, Sharma, Shruti and Kaur, Gurbir.(EFFECT OF STEEL AND POLYPROPYLENE FIBRES ON STRENGTH CHARACTERISTICS OF FLY ASH CONCRETE) International Journal of Research in Advent Technology, Vol.2, No.3, March 2014 E-ISSN: 2321-9637. 4) Vikrant S. Vairagade*, Kavita S. Kene (Experimental Investigation on Hybrid Fiber Reinforced Concrete) International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 2, Issue 3, May-Jun 2012, pp.1037-1041 16) M.S.Shetty, “Concrete Technology Theory and Practice” S Chand company limited , New Delhi .

1. Ashour S.A., Mahmood K. and Wafa F.F., “Influence of Steel Fibers and Compression Reinforcement on Deflection of High-Strength Concrete Beams”, ACI Structural Journal, V. 94, No. 6, Nov.-Dec. 1997, pp. 611-624. 2. Bairagi N.K. and Modhera C.D., “Shear Strength reinforced concrete”, ICI Journal, Jan-March 2001, pp. 47-52. International Journal of Advanced Engineering Technology E-ISSN 0976-3945 IJAET/Vol.III/ Issue I/January-March, 2012/42-45 3. Balaguru, P. N., and Shah, S. P., Fiber-Reinforced Cement Composites, Singapore, McGraw-Hill, 1992. 4. Banthia, N., and Sheng, J., “Fracture Toughness of MicroDEPARTMENT OF CIVIL ENGINEERING KBN COLLEGE OF ENGINEERING, KLABURAGI

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Fiber Reinforced Cement Composites”, Cement and Concrete Composites, Vol. 18, 1996, pp. 251-269. 5. Bentur, A., and Mindess, S., Fiber Reinforced Cementitious Composites, London, Elsevier Applied Science, 1990. 6. Chen Pu - Woei, Chung D. D .L. “A Comparative Study of Concretes Reinforced with Carbon, Polyethylene, and Steel Fibers and Their Improvement by Latex Addition”, ACI Material Journal, V. 93, March-April 1996, pp. 129133. 7. Desai A.K., “Earthquake Resistant Ductile Concrete”, NBM & CW, Oct 2007, pp.144-159. 8. Gustavo J. Parra-Montesi, “High-Performance FiberReinforced Cement Composites: An Alternative for Seismic Design of Structures” ACI Structural Journal, V. 102, No. 5, September-October 2005,pp 668-675. 9. Kim Dong-Joo, Naaman A. E., and El-Tawil S., “High Performance Fiber Reinforced Cement Composites with Innovative Slip Hardending Twisted Steel Fibers”,International Journal of Concrete Structures and Materials, Vol.3, No.2, December 2009, pp. 119-126. 10. Mirsayah A. and Banthia N., “Shear Strength of Steel Fiber-Reinforced Concrete”, ACI Material Journal, V.99, Sep-Oct 2002, pp. 473-479. 11. Parameswaran V.S., “High - Performance Fiber Reinforced Concretes”, Indian Concrete Journal, Nov. 1996, pp. 621-627. 12. Valle M. and Buyukozturk O., “Behavior of Fiber Reinforced High-Strength Concrete under Direct Shear”, ACI Material journal, V.90, No.2, Mar.-Apr. 1992, pp. 122-133. 13. S. Eswari, P.N.Raghunath, K. Suguna, “Ductility Performance of Concrete with Dramix Steel Microreinforcement”, Advances in Natural and Applied Sciences, 2(3), 2008, pp. 243-248. 14. Dave U. V. and Desai Y. M. “Effect of Polypropylene, Polyester and Glass fibres on various strength of ordinary and standard concrete”, The First International Conference On Recent Advance In Concrete Technology, Sep. 2007,Washington D.C. U.S.A. 15. ACI Committee 544, “Measurement of Properties of Fiber Reinforced concrete”.

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MECHANICAL PROPERTIES OF CONCRETE USING FLYASH WITH ADDITION OF POLYPROPYLENE FIBRES

ABSTRACT The addition of fibres to concrete considerably improves its structural characteristics. Fibre reinforced concrete contains short discrete fibres that are uniformly distributed and randomly oriented. Fibres include polypropylene fibres, steel fibres, glass fibres, synthetic fibres and natural fibres each of which lend varying properties to the concrete. The hybrid combination of metallic and nonmetallic fibres can offer potential advantages in improving concrete properties.

As concrete is the most commonly used material in construction, improvement of cementitious material become more and more essential. Conventional concrete has two major drawbacks: low tensile strength and a destructive and brittle failure. In an attempt to increase concrete ductility and energy absorption, polypropylene fibre reinforced concrete (PFRC) has been introduced. This study is part of a research program on evaluating the performance of polypropylene fibre reinforced concrete. An experimental investigation explored properties such as compressive strength, flexural strength, and split tensile strength of polypropylene fibre reinforced concrete. The fibre volume fraction Vf ranges from 0 to 2%. No significant change is found for compressive strength but flexural, split tensile improves greatly, when compared to the plain concrete.

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