Influence of Glass Fibres on High Performance Concrete

Influence of Glass Fibres on High Performance Concrete

Vishal, E.

1. ech Structural Engineering SASTRA University Thanjavur, India

   Prof. Jai Shankar, P.

   Assistant Professor-II, School of Civil Engineering SASTRA University

   Thanjavur, India

   Abstract Normal concrete will have limited ductility, has little resistance to crack and low tensile strength. Inorder to improve these properties, an attempt was executed to study the effect of glass fibres in high performance concrete. The concrete mix design prepared is M40 grade. In this experimental investigation, glass fibres were added in different percentages such as 1%, 2%, 3%, 4%, 5% and their effect on mechanical properties of concrete were studied. A total of 54 specimens such as cubes of size 150x150x150 mm, cylinders of size 100×200 mm and prisms of size 500x100x100 mm were prepared and tests like compression test, flexural strength test, tensile strength test were carried out. Cubes and cylinders were tested in Compression Testing Machine. Prisms were tested under two point loading in Universal Testing Machine and the results were compared. From the test results, it was observed that 5% glass fibre concrete showed higher strength compared to control specimen. It is inferred that glass fibre imparts higher strength and more ductility to the concrete than plain M40 grade concrete.

   Keywords Glass fibres; Silica fume; Mechanical properties.

   1. INTRODUCTION

      The use of glass fibres in concrete is increasing nowadays. Normal concrete gives low strength, less resistant to crack. If glass fibres are added to concrete,it imparts high tensile strength, controls cracking and also reduces bleeding of water. Also the use of glass fibres yields higher flexural strength and improves ductility properties. Yogesh Iyer Murthy et al (2012) replaced fine aggregate by using 25m and 5cm long glass fibre upto 1.5% in normal M30 grade concrete and found an increase in mechanical strength. P.Sangeetha et al (2010) carried out experimental investigation by wrapping Glass Fibre Reinforced Polymer(GFRP) of Mat types for 42 columns, and found that confinement of columns with GFRP wrap increased the strength and ductility of concrete columns and also found that compressive strength increases with increase in number of plies of GFRP. Sathish Kumar.V et al (2012) carried out a research to determine mechanical properties of Geopolymer Concrete Composites(GCC) containing fly ash,alkaline liquid and glass fibre ,from test results, it was observed that GCC reported higher strength in less curing time when compared with geopolymer and Portland cement concrete. Kavita S Kene et al(2012) studied the effect of steel and glass fibres in concrete and observed that by adding steel fibres at 0.5% y volume of concrete, improved brittleness of concrete. Sung Woo Lee et al(2002) studied the structural characteristics of concrete filled GFRP

      composite piles and observed that axial strength concrete filled GFRP tubes increases due to confinement effect given to concrete by FRP shell, and found when piles have high slenderness ratios, strength and ductility decreased and it cannot fully utilize strength gained by confinement effect.

   2. MATERIALS

      1. Cement

         The cement used is Ordinary Portland Cement (OPC) of 53 grade. The specific gravity of cement is 3.15. For ordinary portland cement, the initial setting time is 55 minutes and final setting time is 600 minutes.

      2. Aggregates

         The fine aggregate (i.e) sand that is available in the local area was used in the concrete mix. Fine aggregate passing through 4.75mm size was used.

      3. Glass fibres

      Glass fibre increases the tensile strength by controlling the occurrence of micro cracks into macro cracks. The use of glass fibre imparts strength to concrete and durability. The glass fibres used was Cem-FIL Anti-crack HD.

      TABLE I. PROPERTIES OF GLASS FIBRE

      Properties	Values
      Youngs Modulus	93.8 GPa
      Specific gravity	1.99
      Poisson Ratio	0.23
      Bulk Density	2.488 g/cc
      Diameter	10m
      Tensile strength	1770 MPa

      Fig. 1. Glass fibre in chopped form

   3. EXPERIMENTAL PROGRAMME

      1. Mix Proportion

         In this study, the mix proportion used is M40. It is designed as per IS 10262:2009 code specification. The mix proportion is given in table 2.

         TABLE II. MIX PROPORTION FOR HPC OF M40 GRADE

         Particulars
         Cement	350 Kg/m3
         Fine aggregate	896 Kg/m3
         Coarse aggregate	1140 Kg/m3
         Water	140 Kg/m3
         Super plasticizer	7 Kg/m3

         The mix proportion is 1:2.56:3.26.

      2. Preparation

         In this experimental investigation,totally 54 specimens were casted which includes cubes, cylinders and prisms. Glass fibres are added in varying percentages such as 1%,2%,3%,4%,5% to the concrete. A total of 18 specimens each were put for cubes of size 0.15×0.15×0.15m, cylinders of size 0.1×0.2m and prisms of size 0.5×0.1×0.1m. Silica fume is added in the range of 20% of cement. The amount of superplasticizer used for the mix is measured and mixed with water. Mixing operation was carried out till homogeneous and uniform concrete was achieved. While mixing, placing and compaction, it was observed that glass fibre is uniformly distributed.The well mixed concrete was poured into moulds for cubes to determine compression strength, cylinders to determine tensile strength, prisms to determine flexural strength. Vibrator was used to provide compaction.

      3. Specimen Details

         The details of specimen is given in the table 3 below.

         TABLE III. WEIGHT FRACTION OF GLASS FIBRE FOR VARIOUS PERCENTAGES

         Where, M:grade of concrete M40; C:Cube; R: Cylinder; P:Prism; V1,V2,V3,V4,V5,V6:Percentage weight fraction of glass fibre by cement.

      4. Test Procedure

      The specimens were taken out from mould exactly after 24 hours and immersed in a tank full of water. After 28 days, the specimens were taken out and various tests were carried out. The compressive strength test and tensile strength test were determined for cubes and cylinders respectively using Compression Testing Machine (CTM). The flexural strength test was carried out for prism using Universal Testing Machine (UTM) under two point load bending test under control.

   4. RESULTS AND DISCUSSION

      1. Compressive Strength

         Table 4 denotes the test results of compressive strength at 28 days. It can be seen that silica fume added concrete showed normal strength. It can be noted that addition of 1% glass fibre to concrete increased the strength by 4.13% at 28 days. Further addition of 2%,3%,4%,5% glass fibres showed improved strength by 5.99%,8.17%, 10.56%, 12.93% at 28 days respectively. It can be seen that addition of 5% glass fibre to concrete shows better and higher strength compared to normal concrete strength.

         Glass fibre %	Specimen	Compressive strength (N/mm2)	Average Compressive strength (N/mm2)
         0%	0a	48	48
         	0b	48.2
         	0c	47.8
         1%	1a	50	50.07
         	1b	49.7
         	1c	50.5
         2%	2a	50	51.06
         	2b	51.5
         	2c	51.7
         3%	3a	52.3	52.27
         	3b	52
         	3c	52.5
         4%	4a	54	53.67
         	4b	53.8
         	4c	53.2
         5%	5a	55	55.13
         	5b	55.5
         	5c	54.9

         TABLE IV. COMPRESSIVE STRENGTH TEST RESULTS

         Specimen name	V1 0%	V2 1%	V3 2%	V4 3%	V5 4%	V6 5%	Number of specimens
         MC	3	3	3	3	3	3	18
         MR	3	3	3	3	3	3	18
         MP	3	3	3	3	3	3	18

         Compressive strength (N/mm2)

         Fig. 2, depicts the variation of compressive strength of glass fibre concrete. By increasing the percentage of glass fibre it shows higher strength.

         60

         50

         40

         30

         20

         10

         0

         0% 1% 2% 3% 4% 5%

         Percentage of Glass fibres

         Fig. 2. Compressive strength of Glass fibres

      2. Tensile Strength

         Table 5 denotes the test results of tensile strength at 28 days. It can be observed that tensile strength is increased by 4.11% on addition of 1% glass fibre when compared with 0% glass fibre concrete. Similarly it can be observed that tensile strength increases by 6%, 8.16%, 10.55%, 12.94% on addition

         of 2%, 3%, 4%, 5% glass fibre respectively. It clearly shows that tensile strength of 5% glass fibre at 28 days shows higher strength than normal concrete.

         TABLE V. TENSILE STRENGTH TEST RESULTS

         Fig. 3, depicts the variation of tensile strength of glass fibre concrete.

         50

         45

         40

         35

         30

         25

         20

         15

         10

         5

         0

         0% 1% 2% 3% 4% 5%

         Percentage of Glass fibres

         Tensile strength (N/mm2)

         Fig. 3. Tensile strength of glass fibres

      3. Flexural Strength

      Table 6 denotes the 28 days flexural Strength test results of prisms. Flexural Strength increases with increasing percentage of glass fibre. The 28 days flexural Strength of 1% glass fibre concrete increases by 27.94% compared to normal 0% glass fibre prism. Also, flexural Strength increases by 41.2%, 49.66%, 55.45%, 60.38% with addition of 2%, 3%, 4%, 5% respectively at 28 days. The 28 days flexural Strength of 5% glass fibre shows higher and better strength in comparison with 0% glass fibre concrete.

      TABLE VI. FLEXURAL STRENGTH TEST RESULTS

      Glass fibre %	Specimen	Tensile Strength (N/mm2)	Average Tensile Strength (N/mm2)
      0%	0a	38.4	38.4
      	0b	38.56
      	0c	38.24
      1%	1a	40	40.05
      	1b	39.76
      	1c	40.4
      2%	2a	40	40.85
      	2b	41.2
      	2c	41.36
      3%	3a	41.84	41.81
      	3b	41.6
      	3c	42
      4%	4a	43.2	42.93
      	4b	43.04
      	4c	42.56
      5%	5a	44	44.11
      	5b	44.4
      	5c	43.92

      Glass Fibre %	Specimen	Flexural Strength (N/mm2)	Average Flexural strength (N/mm2)
      0%	0a	0.154	0.147
      	0b	0.138
      	0c	0.15
      1%	1a	0.202	0.204
      	1b	0.206
      	1c	0.204
      2%	2a	0.252	0.250
      	2b	0.244
      	2c	0.254
      3%	3a	0.29	0.292
      	3b	0.2918
      	3c	0.294
      4%	4a	0.326	0.330
      	4b	0.332
      	4c	0.33
      5%	5a	0.374	0.371
      	5b	0.37
      	5c	0.368

      Fig. 4, depicts the variation of flexural Strength of glass fibre concrete.

      0.4

      0.35

      Flexural strength (N/mm2)

      0.3

      0.25

      0.2

      0.15

      0.1

      0.05

      0

      Fig. 4. Flexural strength of Glass fibres

   5. CONCLUSIONS

The present work deals with the use of glass fibre in concrete which is obtained as a waste product from glass industry. The addition of glass fibre into concrete improves the mechanical strength at 28 days. From the results obtained, it is evident that mechanical strength of concrete increases with increasing percentages of glass fibre at 28 days. Therefore it is concluded that addition of 5% glass fibre to concrete showed higher mechanical strength and durability compared to control specimen.

REFERENCES

1. Yogesh Iyer Murthy, Apoorv Sharda, and Gourav Jain, Performance of Glass Fiber Reinforced Concrete, International Journal of Engineering and Innovative Technology, vol.1, June 2012.

2. P.Sangeetha, and R.Sumathi, Behaviour of glass fiber wrapped concrete columns under uniaxial compression, International Journal of Advanced Engineering Technology, vol. I, pp. 74-83, April-June 2010.

3. V.Sathish Kumar, Blessen Skariah Thomas, and Alex Christopher, An Experimental Study on the Properties of Glass Fibre Reinforced Geopolymer Concrete, International Journal of Engineering Reearch and Applications, vol. 2, 2012, pp.722-726.

4. Kavita S Kene, Vikrant S Vairagade, and Satish Sathawane, Experimental Study on Behavior of Steel and Glass Fiber Reinforced Concrete Composites, Bonfring International Journal of Industrial Engineering and Management Science, vol. 2, December 2012.

5. IS 10262-2009, Recommended guidelines for Concrete Mix Design, Bureau of Indian Standards, New Delhi.

6. K. Chandramouli, Srinivasa Rao, N. Pannirselvam, T. Seshadri Sekhar and P. Sravana,Strength properties of glass fiber concrete, ARPN Journal of Engineering and Applied Sciences, vol. 5, 2010, pp.1-5.

7. Faiz A. Mirza, and Parviz Soroushian, Effects of Alkali-Resistant Glass Fiber Reinforcement on Crack and Temperature Resistance of Lightweight Concrete, Cement & Concrete Composites, 2002, pp.223- 227.

8. R. Griffths, and A. Ball, An Assessment of the Properties and Degradation Behaviour of Glass Fibre Reinforced Polyester Polymer Concrete, Composites Science and Technology, 2000, pp.2747-2753.

9. P. N. Balaguru and S. P. Shah, Fiber Reinforced Cement Composites," McGraw-Hill Inc., 1992.

10. V. Vairagade and K. Kene, Experimental Investigation on Hybrid Fiber Reinforced Concrete, International Journal of Engineering Research and Applications, vol. 2, 2012, pp. 1037-1041.