COMPARITIVE STUDY OF COIR FIBRE REINFORCED CONCRETE AND NYLON FIBRE REINFORCED CONCRETE GUIDED BY Mr.K.Mahendran. M.E., Assistant professor Department of Civil Engg SIT Project work done by: B.Karthic Raja (91707103304) A.Karuppasamy (91707103306) N.Navaneetha Krishanan (91707103308) K.Sivarajan (91707103312)
ABSTRACT The comparative study have been carried out using coir fiber and nylon fiber concrete with a fiber content of 1 %, 2 % & 3 % respectively The compressive strength and flexural strength has been analyzed for 7 days and 28 days for cubes and beams
INTRODUCTION This paper presents the versatility of coconut fibres and its applications in different branches of engineering, particularly in civil engineering as a construction material. Nylon can be used as the matrix material in composite materials, with reinforcing fibres like glass or carbon fiber; such a composite has a higher density than pure nylon.
FIBRE REINFORCED CONCRETE Fibre reinforced concrete (FRC) is concrete containing fibrous material which increases its structural integrity It contains short discrete fibres that are uniformly distributed and randomly oriented Fibres include steel fibres, glass fibres, synthetic fibres and natural fibres. Within these different fibres that character of fibre reinforced concrete changes with varying concretes, fibre materials, geometries, distribution, orientation and densities
APPLICATIONS OF FRC The inclusion of fibres in concrete is to delay and control the tensile cracking of composite material Fibres thus transform inherent unstable tensile crack propagation to a slow controlled crack growth This crack controlling property of fibre reinforcement delays the initiation of flexural and shears cracking It imparts extensive post cracking behaviour and significantly enhances the ductility and the energy absorption capacity of the composite Concrete have wide variety of usages in structures such as heavy-duty pavements, Airfields, industrial floor, water retaining and hydraulic structures, parking structure decks, water and waste water treatment plants, pipes, precast roof and wall panels, and the techniques of shotcrete application.
Cement Fine aggregate Coarse aggregate Water Coir fibre & Nylon fibre MATERIAL PROPERTIES Cement Fine aggregate Coarse aggregate Water Coir fibre & Nylon fibre
CEMENT PPC 43 grade cement was used for this investigation & the specific gravity of cement was 3.05
FINE AGGREGATE The fine aggregate used for this investigation was clean river sand passing through 4.75 mm sieve with the fineness modulus of 3.4 and specific gravity of 2.56. The particle size distribution is given in table below and this sample falls in zone II as per BIS 383 – 1970
SIEVE ANALYSIS OF FINE AGGREGATE Sieve size in mm Weight of materials retained in gram % of materials retained Cumulative % of materials retained % of passing 4.75 100 2.36 126 12.6 87.4 1.18 365 36.5 49.1 50.9 0.60 332 33.2 82.3 17.7 0.30 155 15.5 97.8 2.2 0.15 22
COARSE AGGREGATE The size of crushed granite angular aggregate used in this test was between 20 mm and 4.75 mm with the specific gravity of 2.74 Sieve size in mm Weight of materials retained in gram % of materials retained Cumulative % of materials retained % of passing 20 100 10 1000 4.75 2.36 1.18 0.60 0.30 0.15
WATER Water used for this experimental investigation is fit for concreting and the same water is used for curing purpose also. PH value of water = 7.5
COIR FIBRE
Coir is a natural fibre extracted from the husk of coconut and used in products such as floor mats, doormats, brushes, mattresses etc. Technically coir is the fibrous material found between the hard, internal shell and the outer coat of a coconut. Coir fibres are found between the hard, internal shell and the outer coat of a coconut. The individual fibre cells are narrow and hollow, with thick walls made of cellulose Each cell is about 1 millimetre (0.04 in) long and 10 to 20 micrometres (0.0004 to 0.0008 in) in diameter.
Total world coir fibre production is 250,000 tonnes Total world coir fibre production is 250,000 tonnes .The coir fibre industry is particularly important in some areas of the developing world. India, mainly the coastal region of Kerala State, produces 60% of the total world supply of white coir fibre Over 50% of the coir fibre produced annually throughout the world is consumed in the countries of origin, mainly India. Together India and Sri Lanka produce 90% of the 250,000metric tons of coir produced every year
Nylon Fibre
Fibres have been used as reinforcement since ancient times. By the 1960s, steel, glass (GFRC), and synthetic fibres such as polypropylene fibres were used in concrete, and research into new fibre reinforced concretes continues today There was a need to find a replacement for the asbestos used in concrete and other building materials
Effects of fibre in concrete Fibres are usually used in concrete to control cracking due to both plastic shrinkage and drying shrinkage They also reduce the permeability of concrete and thus reduce bleeding of water. The amount of fibres added to a concrete mix is expressed as a percentage of the total volume of the Admixtures. typically ranges from 0.1 to 3% However, fibres which are too long tend to "ball" in the mix and create workability problems. the use of micro fibres offers better impact resistance compared with the longer fibres
MIX DESIGN M 20 GRADE OF ORDINARY CONCRETE Compressive strength required in the field at 28 days = 20 N / mm2 Maximum size of aggregate = 20 mm Specific gravity of cement = 3.027 Specific gravity of fine aggregate (sand) = 2.74 Specific gravity of coarse aggregate = 2.68
TARGET MEAN STRENGTH OF CONCRETE fck = fck+ ( t x s) f ck = Target mean strength f ck = characteristic compressive strength t = A statistic depending upon the accepted proportion of low results and the number of tests. S = standard deviation as per table f ck = fck + ( t x s ) f ck = 20 + ( 1.65 x 4.6) f ck = 27.59 N / mm2
MOULD DETAILS Cube Mould size : 150mm X 150mm X 150mm Beam Mould Size : 100mm X 100mm X 500mm
Materials required per Cube Cement : 1.215 kg Fine aggregate : 1.830 kg Coarse aggregate : 3.650 kg Water : 607 ml Materials required per Beam Cement : 1.800 kg Fine aggregate : 2.700 kg Coarse aggregate : 5.400 kg Water : 900 ml
Amount Of Fibre Required Weight of fibre in grams Per Cube Per Beam 1 % 12.15 18 2 % 24.3 36 3 % 36.45 54
MIXING
Hand mixing is adopted in this study as the quantity of concrete required per batch was very small Cement, required amount of fine aggregate were mixed thoroughly and kept ready Then required quantity of coarse aggregate is added to the foresaid mix and mixing is again done The required quantity of water is then added with the mix. In the prepared mix the required percentage of different fibre is added and mixed thoroughly
CASTING
The specimens were cast in cast-iron steel moulds The inside of the moulds is applied with oil to facilitate the easy removal of specimens Concrete mix is placed in three layers and each layer is compacted with table vibrator
CURING
After 24 hours, the specimens were demoulded and the respective specimens were immersed in normal water for curing. . After 7 days and 28 days of curing, the specimens were subjected to the compression strength and Flexural strength test.
TESTS CONDUCTED # COMPRESSION STRENGTH TEST
# FLEXURAL STRENGTH TEST
RESULTS AND DISCUSSIONS
FLEXURAL STRENGTH OF BEAMS
Flexural strength in N/mm2 Flexural Strength Results for 7 days Beam specimen for Coir Fibre Concrete % of fibre Flexural strength in N/mm2 0 % 4.5 1 % 5.2 2 % 5.4 3 % 4.8
Flexural strength in N/mm2 Flexural Strength Results for 7 days Beam specimen for Nylon Fibre Concrete % of fibre Flexural strength in N/mm2 0 % 4.5 1 % 5 2 % 5.2 3 %
Flexural strength in N/mm2 Flexural Strength Results for 7 days Beam specimen for Coir And Nylon Fibre Concrete % of Fibre Flexural strength in N/mm2 COIR FIBRE NYLON FIBRE 0 % 4.5 1 % 5.2 5 2 % 5.4 3 % 4.8
Flexural strength in N/mm2 Flexural Strength Results for 28 days Beam specimen for Coir Fibre Concrete % of fibre Flexural strength in N/mm2 0 % 4.9 1 % 5.7 2 % 5.9 3 % 5.5
Flexural strength in N/mm2 Flexural Strength Results for 28 days Beam specimen for Nylon Fibre Concrete % of fibre Flexural strength in N/mm2 0 % 4.9 1 % 5.2 2 % 5.35 3 % 5.5
Flexural strength in N/mm2 Flexural Strength Results for 28 days Beam specimen for Coir And Nylon Fibre Concrete % of Fibre Flexural strength in N/mm2 COIR FIBRE NYLON FIBRE 0 % 4.9 1 % 5.7 5.2 2 % 5.9 5.35 3 % 5.5
COMPRESSIVE STRENGTH OF CUBES
Compressive strength in N/mm2 Compressive Strength Results for 7 days cube specimen for COIR FIBRE CONCRETE % of fibre Compressive strength in N/mm2 0 % 14 1 % 15 2 % 17 3 % 13
Test cubes Compressive strength in N/mm2 Compressive Strength Results for 7 days cube specimen for NYLON FIBRE CONCRETE % of fibre Test cubes Compressive strength in N/mm2 0 % 14 1 % 16 2 % 18 3 %
Compressive strength in N/mm2 Compressive Strength Results for 7 days cube specimen for Coir And Nylon Fibre Concrete % of Fibre Compressive strength in N/mm2 COIR FIBRE NYLON FIBRE 0 % 14 1 % 15 16 2 % 17 18 3 % 13
Compressive strength in N/mm2 Compressive Strength Results for 28 days cube specimen for Coir Fibre Concrete % of fibre Compressive strength in N/mm2 0 % 21 1 % 22 2 % 24 3 % 20
Compressive strength in N/mm2 Compressive Strength Results for 28 days cube specimen for Nylon Fibre Concrete % of fibre Compressive strength in N/mm2 0 % 21 1 % 25 2 % 28 3 % 22
Compressive strength in N/mm2 Compressive Strength Results for 28 days cube specimen for Coir And Nylon Fibre % of Fibre Compressive strength in N/mm2 COIR FIBRE NYLON FIBRE 0 % 21 1 % 22 25 2 % 24 28 3 % 20
CONCLUSION By addition of 2 % of fibre content to the concrete has much strength than the other Nylon fibre gives good Compressive strength and coir fibre is good in Flexural strength At low cost of fibres the optimum strengths are achieved than the other fibres like steel fibres, glass fibres etc.,
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