![](wp-content/uploads/doi-ijert-logo.png)
- Open Access
- Total Downloads : 431
- Authors : Premlal. V G , A. Nizad
- Paper ID : IJERTV4IS090409
- Volume & Issue : Volume 04, Issue 09 (September 2015)
- DOI : http://dx.doi.org/10.17577/IJERTV4IS090409
- Published (First Online): 22-09-2015
- ISSN (Online) : 2278-0181
- Publisher Name : IJERT
- License:
This work is licensed under a Creative Commons Attribution 4.0 International License
Strength and Durability Characterestics of Steel Fibre Reinforced Concrete Containing Copper Slag as Partial Replacement of Fine Aggregate
Premlal. V G
M.Tech Student, Department of Civil Engineering,
T.K.M College of Engineering, Kollam, Kerala, India
Prof. A. Nizad
Associate Proffesor, Department of Civil Engineering,
T.K.M College of Engineering, Kollam, Kerala, India
Abstract – This paper focuses on the strength and durability characterestics of steel fibre reinforced concrete containing copper slag as partial replacement of fine aggregate. Mix proportioning has to be done for M20 normal concrete. Sand is replaced with copper slag in proportions of 0%, 10%, 20%, 30%, 40%, 50% & 60%. In all mixes, the proportion of steel fibre is kept constant i.e., 0.2% by volume of concrete. All hybrid mixes were tested and then found that Steel fibre reinforced concrete containing copper slag as 40 % Partial replacement of fine aggregate gives maximum strength and durability criteria.
Key Words: Copper Slag, Steel Fibre, Partial Replacement, Compressive Strength, Optimum Mix, Accelarated Corrosion Process etc.
-
INTRODUCTION
Normal concrete, widely used as a construction material, has many advantages including an ability to be cast, low cost, good durability, fire resistance, energy efficiency, onsite fabrication and aesthetics. However, concrete also has many disadvantages including low tensile strength, low ductility and large variability. Concrete is a most versatile construction material because it is designed to withstand the harsh environments. Engineers are continually pushing the limits to improve its performance with the help of innovative chemical admixtures and supplementary materials. The use of these by products not only helps to utilize these waste materials but also enhances the properties of concrete in fresh and hydrated states.
Common river sand is expensive due to excessive cost of transportation from natural sources. Also large- scale depletion of these sources creates environmental problems. Hence substitute or replacement product for concrete industry needs to be found.. Copper slag is an industrial by-product material produced from the process of manufacturing of copper. Due to its less tensile strength, concrete is subjected to crack on loading. These cracks will propagate in all the three directions. Concrete technologists have found that
reinforcement with randomly distributed short fibres may improve the toughness of the cementitious materials by preventing or controlling the initiation, propagation of crack.
This work aims at the study of strength and durability variations observed by the incorporation of copper slag as partial replacement of sand in steel fibre reinforced concrete and then compared with the strength & durability properties of conventional concrete.
-
OBJECTIVES
To investigate the development of strength and durability characteristics of copper slag admixed steel fibre reinforced concrete and compare with normal concrete.
-
TESTING OF MATERIALS
Cement
Ordinary Portland cement (OPC) confirming to IS-12269
(53 Grade) having specific gravity of 3.14 and fineness of 4
% was used.
Copper slag
Copper slag with specific gravity 3.91 and fineness modulus 3.47 was used.
Fine aggregate
Manufacture sand conforming to Grading zone II of IS:
383 1970 having specific gravity of 2.6 and fineness modulus 2.47 was used.
Coarse aggregate
Crushed angular metal of 12 mm size having specific gravity of 2.78 and fineness modulus of 6.92 was used.
Steel fibre
Steel fibre of crimpled type, density 7.2 gm/cc having aspect ratio 56 was used.
Water
Potable clean water was used.
-
MIX PROPORTION
The mix design is done for M20 concrete as per IS: 10262- 1982.
Table.1 Mix proportions (Kgm3) and Mix ratio
Cement
Coarse
Aggregate
Fine Aggregate
Wate
r
333
1020
925
170
1
3.08
2.78
0.51
Mix Designation
Copper slag
(%)
Steel fibre (%)
CS0
0
0
CS1
10
0.2
CS2
20
0.2
CS3
30
0.2
CS4
40
0.2
CS5
50
0.2
CS6
60
0.2
-
MIX DESIGNATION Table.2 Mix Designation
-
EXPERIMENTAL RESULTS
The various tests of strength and durability were performed, tabulated and analysed the results.
-
Results of Strength Tests Compressive Strength
Table.3 Compressive Strength
Mix Designation
Compressive Strength (MPa)
3 day
7 day
28 day
CS0
24
26
35
CS1
25.5
28
37
CS2
27
29.5
38.5
CS3
28
31
40
CS4
29.5
33
42.5
CS5
27.5
29
39
CS6
25
26.5
36
Fig.1 Variation of Compressive
Strength at 3rd, 7th & 28th days
Flexural Strength
Table.4 Percentage Increase in Flexural Strength at 28th day
Mix Designation
Flexural
Strength (MPa)
Increase in Flexural Strength (%)
CS0
3.41
–
CS1
3.72
9.09
CS2
4.02
17.89
CS3
4.10
20.23
CS4
4.19
22.87
CS5
4.01
17.59
CS6
3.60
5.59
Fig.2 Variation of Flexural Strength at 28th day
Split Tensile Strength
Table.5 Percentage Increase in Split Tensile Strength at 28th day
Mix Designation
Split Tensile Strength (MPa)
Increase in Split tensile strength (%)
CS0
2.83
–
`CS1
3.12
10.25
CS2
3.47
22.61
CS3
3.60
27.21
CS4
3.75
32.51
CS5
3.33
17.67
CS6
3.25
15.19
Fig.3 Variation of Split Tensile Strength at 28th day
Modulus of Elasticity
Table.6 Modulus of Elasticity at 28th day
Mix Designation
Modulus of Elasticity (MPa)
Increase in Modulus of Elasticity (%)
CS0
40401
–
CS1
42365
4.86
CS2
51044
26.34
CS3
52490
29.92
CS4
54752
35.52
CS5
45132
11.71
CS6
43844
8.52
Fig.4 Variation of Modulus of Elasticity at 28th day
Impact Resistance
Table.7 Impact Resistance at 28th day
Mix Designation
No. of blows required for first crack (X)
No. of blows required for
Ultimate failure (Y)
CS0
11
20
CS1
18
36
CS2
26
60
CS3
33
72
CS4
53
108
CS5
49
90
CS6
40
79
Fig.5 Variation of Impact Resistance at 28th day
-
Fixing the Optimum Mix
Optimum mix in the view of Strength consideration is Steel Fibre Reinforced Concrete Containing Copper Slag as 40
% Partial Replacement of Fine Aggregate (CS4) and that mix is selected for studying the Durability characteristics by comparing with Normal mix.
-
Results of Durability Tests
Accelerated Corrosion Process (Galvano Static Weight Loss Method)
Table.8 Results of Accelerated Corrosion Process (Uncoated rebar)
Mix Desig nation
Weight of rod (gm)
Loss in Weight (gm)
Corrosion Rate (mm/yr)
Before
corrosion
After
corrosion
CS0
230
228
2
0.35
CS4
230
220
10
1.75
Table.9 Results of Accelerated Corrosion Process (Coated rebar)
Mix Design ation
Weight of rod (gm)
Loss in Weight (gm)
Corrosion Rate (mm/yr)
Before
corrosion
After
corrosion
CS0
230
230
NIL
NIL
CS4
230
230
NIL
NIL
Acid Attack
Copper slag admixed concrete shows 23.59 & 34.29 % reduction of in compressive strength when compared to normal mix at 56 & 90 days due to acid attack.
Sulphate Attack
Copper slag admixed concrete shows 1.18 & 4.71 % reduction in compressive strength when compared to normal mix at 56 & 90 days due to sulphate attack.
Bulk Diffusion
Table.10 Penetration of Chloride Ions
Mix Designation
Depth of Penetration of Chloride Ions (mm)
at 56 day
at 90 day
CS0
30
33
CS4
25
27
Mix Designation
Diffusion coefficient (10-12 ) m2/Sec
at 56 day
at 90 day
CS0
11.63
8.75
CS4
8.07
5.84
Table.11 Diffusion Coefficient
Carbonation
Mix Designation
Carbonation Depth (mm)
at 56 day
at 90 day
CS0
5
8.3
CS4
2
3.2
Table.12 Carbonation Depth
-
Copper slag admixed concrete shows higher energy absorption value and this is attributed to the ductile nature of copper slag admixed beams. Maximum percentage increase in flexural strength is 22.87 %.
-
Maximum percentage increase in split tensile strength is
32.51 %.
-
Maximum percentage increase in modulus of elasticity is
35.52 %.
Rapid Chloride Permeability Test
Table.13 Chloride Permeability at 56 day
Mix Designation
Total Charge Passed (Coulombs)
ASTM C-1202
Classification
CS0
405
Very Low
CS4
520
Very Low
Table.14 Chloride Permeability at 90 day
Mix Designation
Total Charge Passed (Coulombs)
ASTM C-1202
Classification
CS0
558
Very Low
CS4
710
Very Low
-
-
CONCLUUSION
-
The strength parameters are optimum when the concrete containing 40 % replacement of fine aggegate by copper slag.
-
Due to low water absorption, coarser & glassy surface of copper slag, the workability of concrete increases when the
% of copper slag increases.
-
High toughness of copper slag attributes to the increased compressive strength. Maximum percentage increase in compressive strength is 21.43 %. When copper slag % is greater 40, there is a reduction in compressive strength. This is due to the increased voids and increased free water content.
-
It is recommended that if the copper slag admixed concrete is to be used in corroded environment, the reinforcement should be coated with some protective coating.
-
Copper slag admixed concrete specimens showed lesser resistance to acid attack due to its higher mass and higher resistance to sulphate attack, chloride attack and carbonation.
-
Chloride penetration of copper slag admixed concrete is graded under the category very low. It is indicating the lesser permeability of slag admixed concrete.
-
-
REFERENCES
-
D. Brindha and S. Nagan (2010), Durability Studies on Copper Slag Admixed Concrete, Asian Journal Of Civil Engineering (Building And Housing), Vol. 12, No. 5 563-578
-
D. Brindha et al. (2010), Assessment of Corrosion and Durability Characteristics of Copper Slag Admixed Concrete, International Journal Of Civil And Structural Engineering, Volume 1, No 2, 192- 211
-
Binaya Patnaik et al. (2015), Strength and Durability Properties of Copper Slag Admixed Concrete, International Journal of Research in Engineering and Technology, Volume 4, 158-166
-
Amit Rana (2013), Some Studies on Steel Fibre Reinforced Concrete, International Journal of Emerging Technology and Advanced Engineering, Volume 3, 120-127
-
A. Sivakumar and Manu Santhanam, Mechanical Properties of High Strength Concrete Reinforced with Metallic and Non-metallic Fibres, Cement and Concrete Composites, 29(8), 603-608