Self-compacting concrete, which can flow by its own weight and occupy all gaps and restricted regions of the formwork without any external or internal vibrations, is one of the most significant discoveries in concrete science. Workability and mechanical properties such as compressive strength, split tensile strength, and flexural strength were investigated using M30 grade self-compacting concrete with 20% class C fly ash mineral admixture and fine aggregate with copper slag in proportions of 0, 20, 40, 60, and 80% in this paper. This mix % also includes two chemical admixtures, Auramix 200 and Conplast SP430. Adding fly ash to the paste, according to the observations, improves volume while also improving workability. In terms of compressive strength, copper slag at 60% yielded good results. The greatest results for split tensile and flexural strength were obtained when up to 40% of the fine aggregate was substituted with copper slag. When compared to the nominal mix, compressive strength improved by 15.18 percent, split tensile strength increased by 12.9 percent, and flexural strength increased by 18.8 percent at 28 days.
Research Article
Self-Compacting Concrete with Copper Slag as Fine Aggregate-Experimental Study
https://doi.org/10.21203/rs.3.rs-1610673/v1
This work is licensed under a CC BY 4.0 License
Version 1
posted
You are reading this latest preprint version
Self Compacted Concrete
Class C Fly ash
Copper Slag
Tests on Hardened Concrete
SCC concrete self-consolidates without the need for external vibration, allowing for faster concrete pouring and lower labour costs. Vibration isn't required at this site. This was built in 1988 as a prototype for field testing and implementation by Japanese researchers. Compaction is heavily influenced by material characteristics and replacement proportions. There is no unique mix design technique for self-compacting concrete. Without clogging the reinforcement or being severely vibrated, the self-compacting concrete flows easily into the formwork at the right speed. The use of mineral additives is one of the primary differences between normal concrete and self-compacting concrete. According to EFNARC, in order to improve cementitious content, we must increase cement content, which is the most expensive component of concrete. Mineral admixtures lower the cement content while boosting the cementitious content and lowering the cost of concrete. Concrete strengthening additives can also aid to promote particle packing and decrease pore structure. SCC concrete flows and compacts in dense reinforcement without the usage of external or internal vibration. Higher binder concentrations and considerable doses of chemical admixtures (super plasticizers) improve fluidity and stability while reducing segregation and bleeding when compared to conventional concrete. Copper slag is a by-product of copper smelting and refining that is left over from the matte side of the process. Currently available slag management options include recycling, metal recovery, value products, and disposal in slag heaps or stockpiles. Self-compacted concrete offers advantages such as easier concrete placing, faster construction, improved surface smoothness, thinner concrete sections, reduced site workforce, improved durability, safer working environment, and more design freedom. SCC may be employed in the precast domain, as well as in challenging dense steel reinforcing, Cooling tower tank bund sites with natural draughts, marine construction, and high-rise development. More trial batches are needed since the larger paste volume produces more shrinkage and creep, and the mix design and procedure utilised are too complex to implement, as well as being more expensive than ordinary concrete (except for placement costs).
SCC should be built with a high flow capacity, minimum or no segregation, and no corner obstruction. Self-compacting concrete contains a significant amount of cement paste, finer aggregate and water, and an adequate super plasticizer dosage. SCC has a fine aggregate to the coarse aggregate ratio of around one, which is somewhat higher than ordinary concrete. The bulk of SCC design techniques are empirical and vary from traditional design procedures.
Fly ash is a byproduct of the combustion of pulverized coal in power plants. Mineral impurities in coal are suspended during combustion and escape with the exhaust gases. The molten substance condenses into spherically glassy particles known as "fly ash" when it cools. Electrostatic precipitators capture fly ash from exhaust fumes. Although the fine powder resembles "Portland cement," it is not chemically equivalent. Fly ash combines with the byproduct calcium hydroxide produced by the chemical interaction of cement and water to form a new cementitious material that improves a variety of desired concrete properties. To varying degrees, all fly ashes have cementitious qualities, depending on the chemical and physical properties of both the fly ash and the cement. Concrete hardening is delayed because fly ash and calcium hydroxide have a slower chemical reaction than cement and water. Delayd concrete hardening combined with a wide variety of fly ash characteristics can pose considerable problems for the concrete manufacturer and finisher when installing steel-toweled floors. There are two varieties of fly ash: Class C and Class F. Class C is used in levels ranging from 15–40% by weight of cementitious material. Class C fly ash will be more chemically stable and include a higher proportion of calcium oxide. It is frequently made up of high-calcium fly ashes with a carbon proportion of no more than 2%. Class F fly ash is used in doses ranging from 15–25% of the cementitious material's bulk. It reduces the likelihood of sulfate-induced expansion, which can occur in fertilised soils or at the shore. These are typically low-calcium fly ashes with carbon concentrations of less than 5% but occasionally up to 10%. Fly ash is regarded as an environmentally friendly item because it is a result of numerous businesses. In a few locations, it is a more cost-effective alternative to cement. Coloring agents are applied on the job site and come in two different colors. Produces a variety of setup times. It is resistant to cold temperatures, making it simpler to use in the cold. It requires less water than cement, which decreases CO2 emissions and heat of hydration. Traditional builders are opposing fly ash applications due to their inclination to effloresce, as well as substantial concerns about freeze/thaw performance. The use of air-entraining agents has grown in popularity. It takes longer to gain strength. Increased salt scaling as a result of higher quantities of fly Ash. Fly Ash has Seasonal limitation.
Copper slag is granulated metal slag that is used as an abrasive blasting grit (also called as iron silicate). In nature, copper slag has a glassy appearance and granular grain form, with particle sizes similar to sand. Because it has a high concentration of Fe, Si, and Al oxides, it is a pozzolanic material. Bulk density varies from 1900 to 2310 kg/m3, which is approximately comparable to standard fine aggregate bulk density. Each tonne of copper metal produced produces 2.2 tonnes of byproduct, also known as copper slag. Fine aggregates are stated to be in high demand right now, and their replacement is producing a scarcity. Flooding and environmental issues are caused by the excavation of the riverbed. Copper slag is used as a partial replacement for sand to alleviate the ecological imbalance and scarcity.
SCC is employed in Indian projects such as the Metro project in New Delhi, the Nuclear power plant in Kaiga, Karnataka, the Tarapur automic project in Maharashtra, Nathani Heights 75 story in Bombay Central, and the High rise tower 80 storey at Palais Royale in Mumbai.
Cement
The cement employed in this investigation was of the grade OPC 53. The amount required to carry out testing was calculated based on the code requirements and acquired as needed. Table 1 shows the tests used to analyse the qualities of cement, which include the specific gravity test (IS: 1727-1967), the test for normal consistency (IS: 5513-1976), the cement setting time test (IS: 4031 (Part 5) -1988), and the fineness of cement.
|
S.no |
Property |
Test values |
Standard values |
|
1 |
Fineness of cement |
4.12% |
<10% |
|
2 |
Specific gravity |
3.15 |
- |
|
3 |
Consistency |
30.5% |
- |
|
4 |
Initial setting time |
49.5 min |
>30min |
|
5 |
Final setting time |
210min |
<600min |
Table 1 Cement physical properties
Fine Aggregate
IS 383-1970 sand can be used in self-compacting concrete. Sand particles less than 0.125mm are considered powder content in the SCC mix in this sand. Sand that has been crushed as well as sand that has been rounded can be used. You can use either siliceous or calcareous sand. The fine material for this project comes from a nearby river stream. It was sieved through a variety of sieves of different diameters in accordance with IS: 383-1970 (2.36mm, 1.18mm, 600, 300, and 150), and the results are displayed in Table 2. Table 3 specifies the parameters of fine aggregates.
|
Sieve Size |
% passing recommended by IS -383 |
Weight Retained (grams) |
Cumulative weight retained |
Cumulative % weight retained |
Cumulative % weight passing through |
|
10 mm |
100 |
0 |
0 |
0 |
0 |
|
4.75 mm |
90-100 |
0 |
0 |
0 |
0 |
|
2.36 mm |
85-100 |
130 |
130 |
13 |
87 |
|
1.18 mm |
75-100 |
110 |
240 |
24 |
76 |
|
600 micron |
60-79 |
140 |
380 |
38 |
62 |
|
300 micron |
12-40 |
300 |
800 |
80 |
20 |
|
150 micron |
0-10 |
200 |
1000 |
100 |
0 |
Table 2 Sieve Analysis of Fine Aggregate
|
S. no |
Property |
Experimental values |
|
1 |
Specific gravity |
2.7 |
|
2 |
Fineness modulus |
2.55 |
|
3 |
Bulk density (loose) |
15.2KN/m3 |
|
4 |
Bulk density(dense) |
16.8KN/m3 |
|
5 |
Grading |
Zone-Ш |
Table 3 Fine Aggregate Physical Properties
Course Aggregate
The coarse aggregate employed in this work (Fig. 1) is crushed granite with a particle size of 10mm, as defined by IS 383-1970, and the experiments that follow were carried out to determine the characteristics of coarse aggregate as defined by IS 2386-1963. (part-III). Table 4 displays the physical properties of coarse aggregate.
|
S.no |
Property |
Experimental Value |
|
1 |
Specific gravity |
2.75 |
|
2 |
Fineness modulus |
7.26 |
|
3 |
Bulk density(loose) |
15.26KN/m3 |
|
4 |
Bulk density(dense) |
16.2KN/m3 |
|
5 |
Water absorption |
0.4% |
Table 4 Coarse Aggregate physical properties.
Water
Portable water is utilised in the concrete preparation and casting processes. When mixed with cement, fine aggregate, and coarse aggregate, it undergoes a hydration process and gradually builds strength.
Copper Slag
Figure 2 shows copper slag, a siliceous by-product of sterile industries that does not leech when exposed to the environment. Because of its glassy structure and toughness, it has attributes similar to genuine river sand. Table 5 shows the properties of copper slag, while Table 6 shows the chemical makeup.
|
Property |
Experimental value |
|
Color |
Black, glassy |
|
Grain shape |
Angular |
|
Specific gravity |
3.5 |
|
Bulk density |
1750kg/m3 |
|
Fineness modulus |
4.55 |
Table 5 Copper slag properties
|
Chemical composition |
Content (%) |
|
Silica |
35.12 |
|
Free silica |
0.31 |
|
(Al2O3) |
2.99 |
|
Titanium(TiO2) |
0.39 |
|
Iron(Fe2O3) |
57.64 |
|
Calcium (CaO) |
0.23 |
|
Magnesium (MgO) |
0.92 |
|
Sodium(Na2O) |
0.95 |
|
Potassium(K2O) |
1.03 |
|
Copper(Cu) |
0.31 |
Table 6 Chemical composition of Copper slag
Source: Jawahar,144B, Polepettai, West Tuticorin.
Fly ash
Type C fly ash is employed. Fly ash formed from the combustion of lignite or sub-bituminous coal has certain self-cementing capabilities in addition to pozzolanic properties. The addition of water strengthens class C fly ash, making it more difficult to fly as it ages. Class C fly ash typically has a lime content of 20%. Unlike class F fly ash, self-cementing class C fly ash does not require an activator. Class C fly ash has more alkali and sulphate. Table 7 shows the properties of fly ash, while Table 8 shows the chemical makeup.
Fig. 3 Class C Flyash
|
Property |
Experimental value |
|
Specific gravity |
2.2 |
|
Fineness modulus |
4.4kg/m2 |
Table 7 Fly ash properties
|
Chemical Composition |
Content (%) |
|
Silica(SiO2) |
39.90 |
|
Alumina. |
16.70 |
|
Iron |
5.80 |
|
Calcium |
24.30 |
|
Magnesium. |
4.60 |
|
Sodium(Na2O) and Potassium(K2O) |
1.30 |
|
SO3 |
3.30 |
Table 8 Fly ash Chemical composition
Chemical Admixture
In this study, Conplast SP430 (Fig. 4, 5) was used. It's employed when a high amount of workability and retention is essential, such as when there be be delays in installation or when high temperatures will cause quick slump loss. It makes it easier to produce high-quality concrete. Conplast SP430, as a high-range water-reducing admixture, meets IS:9103:1999, BS:5075 Part 3, and ASTM-C-494 Types "F" and "G" at high dosage. "Conplast SP430" appears as a dark liquid that dissolves readily in water. Conplast SP430 was specifically intended to save up to 25% on water without affecting workability or the ability to make high-quality, low-permeability concrete.
Properties of SP 430
- Specific gravity ranges from 120 to 1.22 at 300°C.
- Chloride content - Nil (As per IS: 9103-1999 and BS: 5075)
- Air entrainment - 1% (Approximately.)
- Compatibility: With the exception of high alumina cement, it can be used with any type of cement. When added individually to the mix, Conplast SP430 is compatible with different types of Fosroc admixtures. To optimize doses, number of site trials must be conducted.
- Workability: It can be used to make dynamic concrete that doesn't need to be compacted. To achieve a high working mix without segregation, several modest changes may be required.
- Cohesion: Cement particle dispersion enhances cohesiveness, reduces segregation, and improves surface quality.
- Compressive strength: Conplast SP430 is primarily made up of highly effective super plasticizers that increase workability while retaining compressive strength. Conplast SP430 can be used to produce large water reduction as well as significant compressive strength enhancement.
- Durability: Lowering the W/C ratio allows for increased density and impermeability, which increases the durability of concrete.
Advantages
- It increases workability. Fast placing and compaction.
- Strength increases: If water is reduced in precast concrete, it provides great early strength. It has the advantage of being more durable.
- Risk of segregation and bleeding. reduced
- Free from chloride content, this is safe in pre-stressed concrete and with sulphate-resisting cement.
- It reduces porosity, thereby producing good quality concrete with a denser, close-textured surface.
Dosage and applications
- The best technique to discover the appropriate dose for a concrete mix is to undertake a series of Site trials that track the impacts of workability, strength gain, and cement reduction.
- Conplast SP430 site testing must always be compared to an admixture-free concrete mix.
- As a general rule, the dosage should be between 0.6 and 1.5 litres per 100 kg of cement. If there are any dose differences in specific applications, one has to contact Fosroc Technical Services.
Auramix 200
Auramix 200 (Fig. 6, 7) is a high-performance superplasticizer that sometimes acts as a viscosity modifier that can be used in both low and high-grade concrete and is designed for applications that require significant water reduction and longer workability retention. Auramix 200 was developed for use in concrete with long workability retention and pumpable concrete. Auramix 200 is a unique combination of a new generation super plasticizer and a polycarboxylic ether polymer with a long lateral chain. The electrostatic dispersion mechanism significantly reduces the water demand in flowable concrete. It's a light brown liquid that quickly dissolves in water. Auramix 200 effectively disperses cement particles in the concrete mix, allowing the hydration process to reach a larger surface area. This effect can be used to strengthen concrete, make it more workable, or lower the cement content.
Advantages
Pumping concrete of various grades to greater heights with a low viscosity admixture. A great option is concrete with cement replacements and a low water cement ratio.
- Increases strength without compromising workability or cement content.
- It's perfect for precast concrete.
- The use of a super plasticizer improves workability.
- A lower water-cement ratio means less cracking due to shrinkage.
- Makes the concrete water-resistant.
- Increased resistance to carbonation.
- Mitigate Shrinkage and Creep
- Increased Durability
Properties
- Appearance : Ligh tBrown liquid
- pH: Minimum 6.0
- Volumetricmass@250°C:1.07±0.02kg/liter
- Chloride content: Nil as per BS 5075
Dosage
To determine the appropriate dosage of Auramix 200 to meet a specific requirement, laboratory and batch studies should always be used. In contrast, normal dosage ranges between 0.3 and 1.5 percent by weight of total cement or binder content. Dosage above limits is utilised in consultation with the Berger Fosroc technical department to achieve specific blend criteria. Overdosing can cause delays in setting and segregation. When stored between 20oC and 500oC, Auramix 200 has a minimum shelf life of one year.
Mix Design
In self-compacting concrete, there is no standard process for determining mix proportions. On the other hand, EFNARC requirements include a number of proportional constraints. The mix design is first carried out in compliance with IS 10262–2019, and the quantities of each material are then established by confirming the EFNARC-specifications.
Design
- Grade of concrete = M30
- Cement grade = 53 Grade
- Maximum size of coarse aggregate = 10mm
- Specific gravity of coarse aggregate = 2.75
- Specific gravity of copper slag = 3.5
- Specific gravity of fly ash = 2.2
- Specific gravity of fine aggregate = 2.7
- Fine aggregate zone = Zone Ш
- Specific gravity of cement = 3.15
Procedure
Step-1: Determination of Target mean strength (fck׳)
f'ck = fck+1.65*S (or) fck+X
S= Standard deviation from Table 1 IS10262- 2019 (S=5)
fck = 38.25MPa
fck = characteristic compressive strength at 28 days
Step-2 Selection of water/cement ratio
W/C = 0.4 (after many trails)
Step-3: Selection of maximum water content
From table-2 IS 10262-2019
Water content = 208 lit
Step-4: Required water content = 200 lit/m3 (as per EFNARC7.2)
Step-5: Cement content=500 kg/m3
Step-6: Air entrapped - 1%
From table 3 of IS 10262-2019, amount of air entrapped is 1% of total volume for 10mm size of aggregate
Step-7: From table-3 IS 10262-2019
Depending upon zone of fine aggregate, select the volumes of fine and coarse aggregate
Volume of coarse aggregate = 0.48
Volume of fine aggregate = 0.5
Step-8: Mix Calculation
Volume of concrete=1m3
Volume of cement =0.159 m3
Volume of water = 0.2 m3
Volume of total aggregate (e) = 0.641-superplasticizer
1-0.159-0.2 = 0.641m3
Mass of fine aggregate = e x Volume of fine aggregate x Specific gravity of fine aggregate
=0.635Mass of fine aggregate = 891.54kg/m3
Mass of coarse aggregate = e x Volume of fine aggregate x Specific gravity of Coarse aggregate Mass of coarse aggregate = 821.1kg/m3
Step-10: selection of super plasticizer and viscosity modifying agent
SP dosage = 0.8% of powder content
VMA dosage = 0.2% of powder content
Therefore, the Mix proportion obtained is
Cement: F.A: C.A = 1: 1.78: 1.676
Proportion for SCC Mix (Per 1m3)
|
Material |
Nominal Mix |
20% Copper Slag |
40% Copper Slag |
60% Copper Slag |
80% Copper Slag (Kg) |
|
Cement (Kg) |
415 |
415 |
415 |
415 |
415 |
|
Fly Ash (Kg) |
100 |
100 |
100 |
100 |
100 |
|
Copper Slag(Kg) |
- |
186.2 |
372.4 |
558.6 |
744.8 |
|
Water (lit) |
190 |
190 |
190 |
190 |
190 |
|
FA (Kg) |
931 |
744.8 |
558.6 |
372.4 |
186.2 |
|
CA (Kg) |
818 |
818 |
818 |
818 |
818 |
|
SP (lit) |
4.1 |
4.1 |
4.1 |
4.1 |
4.1 |
|
VMA (lit) |
1.03 |
1.03 |
1.03 |
1.03 |
1.03 |
Table 9 Proportion for SCC mix
Mix Notations
- CS-0: Nominal SCC mix with 20% fly ash
- CS-20: 20% Copper Slag with 20% fly ash
- CS-40: 40% Copper Slag with 20% fly ash
- CS-60: 60% Copper Slag with 20% fly ash
- CS-80: 80% Copper Slag with 20% fly ash
The specimen test results were reported, as well as tests for concrete specimens in terms of compressive strength, split tensile strength, flexural strength, and workability of SCC at various curing ages.
Tests on Fresh Concrete
Slump Flow Test
A circular plate with a diameter of 850 mm was used in this test, and it was smooth, watertight, and rigid. Handles must be connected if necessary to prevent the slump flow measurement from being interrupted. Wipe the inside and external sides of the droop cone and plate with a moist towel lying horizontally. Fill the cone to the brim with concrete, then brush away the excess to produce a level surface on top of the cone. Lift the cone vertically gently and slowly, taking measurements of the slump formed on the plate in two perpendicular directions with a scale or measuring tape. The flow values obtained are listed in Table 10. Figure 8 depicts graphs of mix notations vs slump flow.
|
Mix Design |
Mix Notation (%) |
Slump Flow (mm) |
|
70% OPC + 30% FA + 100% Sand + 0% CS |
CS-0 |
690 |
|
70% OPC + 30% FA + 80% Sand + 20% CS |
CS-20 |
705 |
|
70% OPC + 30% FA + 60% Sand + 40% CS |
CS-40 |
716 |
|
70% OPC + 30% FA + 40% Sand + 60% CS |
CS-60 |
730 |
|
70% OPC + 30% FA + 20% Sand + 80% CS |
CS-80 |
740 |
Table 10 Slump flow values
L- Box Test
An L-shaped Rectangular Box is included in this test. Pour the concrete into the vertical rectangular box and use a brush to remove any excess concrete. The gate is then raised, allowing concrete to flow into the horizontal box in proportion to what is left in the vertical component. The L-Box ratio values are shown in Table 11. Figures 9 and 10 exhibit graphs of mix notations vs L-box ratios, respectively, while Figure 11 displays the L-Box Apparatus.
|
Mix Notation (%) |
L-Box Ratio |
H1 |
H2 |
T20 |
T40 |
|
CS-0 |
0.85 |
40 |
34 |
2.0 |
3.0 |
|
CS-20 |
0.89 |
40 |
38 |
1.5 |
2.5 |
|
CS-40 |
0.92 |
39 |
36 |
1.5 |
2.0 |
|
CS-60 |
0.97 |
38 |
37 |
1.0 |
2.0 |
|
CS-80 |
0.95 |
38 |
36 |
1.0 |
2.0 |
Table 11 L-Box ratio values
V-Funnel Test
In this experiment, a V-shaped funnel with a bottom closure was employed, and the required mix of concrete was poured into it up to the brim. Scrape away any excess concrete from the top of the funnel with a spatula, making a smooth surface. The time required for the funnel to empty the concrete is calculated by opening the funnel valve and using a stopwatch. The V-Funnel values are shown in Table 12. Figure 11 depicts graphs of mix notations versus V-Funnel time, while Figure 12 shows the V-Funnel Apparatus.
|
Mix Notation (%) |
V Funnel (sec) |
|
CS -0 |
9.0 |
|
CS -20 |
8.5 |
|
CS -40 |
7.6 |
|
CS -60 |
6.9 |
|
CS -80 |
6.0 |
Table 12 V-Funnel values
Observations
- According to EFNARC, the slump flow produced in the mixtures is in the 650–800 mm range.
- As the percentage of copper slag increased, so did the slump flow value.
- The V-funnel times obtained in the mixes are between 8 and 12 seconds.
- V-funnel time decreases as copper slag content increases.
- L-Box ratios are typically in the 0.8–1 range.
- The L-Box ratio grew as the percentage of copper slag increased.
- Concrete's workability has enhanced.
- Fresh concrete has all of its qualities within the prescribed ranges.
Tests on Hardened Concrete
Compressive Strength Test
It is a test that determines how much compressive load a material can bear before fracturing. In this test, standard-sized cubes of 150x150x150 mm3 were cast, and the maximum load at failure was determined using compression testing equipment. Table 13 displays the compressive strength values. Cubes cast for numerous experiments are depicted in Figure 14. A graph of compressive strength, mixture notations, and days is shown in Figure 15. Figure 16 displays a comparison of compressive strength versus age from 0% replacement to 60% replacement (optimum). Figure 13 depicts the compressive strength comparison of CS-0, CS-20, CS-40, CS-60, and CS-80. Only at 7, 14, and 28 days is the compressive strength test performed. For 7 days, the optimum compressive strength is 32 MPa, for 14 days, 41 MPa, and for 28 days, 44 MPa. It is observed at 30% replacement. Compressive strength increases with increasing copper slag percentage up to 60 percent replacement, then drops to 80 percent replacement. The rise in compressive strength increases as the age of the concrete grows.
|
S.No |
Mix Notation |
Compressive Strength (MPa) |
||
|
7 Days |
14 Days |
28 Days |
||
|
1 |
CS-0 |
25.1 |
33.6 |
38.2 |
|
2 |
CS-20 |
25.7 |
34.9 |
39.4 |
|
3 |
CS-40 |
28.0 |
37.5 |
43.1 |
|
4 |
CS-60 |
32.0 |
41.0 |
44.0 |
|
5 |
CS-80 |
24.0 |
30.2 |
32.4 |
Table 13 Compressive Strength Values
Split Tensile Strength Test
The Split tensile test is performed to see how a material reacts to an axial stretching force. A standard-sized cylinder with a diameter of 150mm and a height of 300mm was cast for this test, and the maximum load at failure was measured using split tensile testing equipment. Table 14 summarises the findings. Figure 18 compares split tensile strength values for CS -0, CS -20, CS -40, CS -60, and CS -80. The split tensile strength is only evaluated at 7, 14, and 28 days. The ideal value of split tensile strength for 7 days at 40% replacement is 2.8 MPa, 3.43 MPa for 14 days, and 3.76 MPa for 28 days. Split tensile strength increases with increasing copper slag content up to 40% replacement and then decreases for 60% and 80% replacement. Figure 19 displays a comparison of split tensile strength with respect to age between 0% and 40% replacement (optimum).
|
S.No |
Mix Notation |
Split Tensile Strength (MPa) |
||
|
7 Days |
14 Days |
28 Days |
||
|
1 |
CS-0 |
2.39 |
2.91 |
3.33 |
|
2 |
CS-20 |
2.53 |
3.20 |
3.62 |
|
3 |
CS-40 |
2.80 |
3.43 |
3.76 |
|
4 |
CS-60 |
2.73 |
3.40 |
3.72 |
|
5 |
CS-80 |
2.20 |
2.70 |
2.90 |
Table 14 split tensile strength test result
Flexural Strength Test
Beams with typical dimensions of 150x150x700 mm3 were cast in the Flexural Strength test, and the maximum load at failure was calculated using flexural testing equipment. The flexural strength of CS-0, CS-20, CS-40, CS-60, and CS-80 is shown in Figure 20. Only at 7, 14, and 28 days is flexural strength measured. At 40% replacement, flexural strength peaks at 4.97 MPa after 7 days, 5.80 MPa after 14 days, and 6.42 MPa after 28 days. Flexural strength increases with increasing copper slag content up to 40% replacement and then decreases for 60% and 80% replacement. Figure 21 displays a comparison of flexural strength with respect to age ranging from 0% to 40% replacement (optimum).
|
S.No |
Mix Notation |
Flexural Strength Value (MPa) |
||
|
7 Days |
14 Days |
28 Days |
||
|
1 |
CS-0 |
4.14 |
4.77 |
5.40 |
|
2 |
CS-20 |
4.35 |
5.08 |
5.80 |
|
3 |
CS-40 |
4.97 |
5.80 |
6.42 |
|
4 |
CS-60 |
4.77 |
5.39 |
6.22 |
|
5 |
CS-80 |
3.94 |
4.35 |
4.56 |
Table 15 Flexural Strength Data
Results
- Slump flow at 40% copper slag =716mm
- V funnel test at 40% copper slag=7.6sec
- L box ratio at 40% copper slag=0.92
- Compressive strength is greatest at 60% copper slag, or 44 MPa.
- The greatest split tensile strength is 3.76 MPa at 40% copper slag.
- Flexural strength is greatest at 40% copper slag, or 6.42 MPa.
The workability qualities of self-compacting concrete are within limitations and improve as the quantity of copper slag increases. The improvement in compressive strength is up to 15.18 percent for 60 percent fine aggregate replacement with copper slag, and 12.8 percent for 40 percent replacement. For a 40% fine aggregate substitution with copper slag, the increase in split tensile strength is up to 12.9%. Flexural strength increases by up to 18.8 percent when 40 percent fine aggregate is replaced with copper slag. The best replacement of copper slag is in the 20 to 40 percent range. All of the beam specimens failed solely due to flexure. VMA dosage is adjusted by the number of trials for good qualities because excessive dosage produced a delay in setting time and segregation, resulting in a drop in strength. Segregation and bleeding occur when the super plasticizer quantity is large. The number of trials influences the dosage. Copper slag has a higher specific gravity than fine aggregate. It makes concrete stiffer by increasing its self-weight.
- Abdullah Mohsen Ahmed Zeyad and Abdullah Mustafa Saba: Influence of Fly Ash on the Properties of Self-Compacting Fiber Reinforced Concrete, Journal of Steel Structures & Construction, volume 3, Issue 1, 2017 (Saba, 2017).”
- “Ankur tayal and Ankit Yaduvanshi: To Study the Mechanical Properties of Self Compacting Concrete Containing Copper Slag, International Journal of Engineering Research & Technology (IJERT), Vol. 8 Issue 04, April-2019 (Yaduvanshi, 2019).”
- “Bertil person(2001) A comparison between mechanical properties of self-compacting concrete and the corresponding properties of normal concrete cement and concrete Research 31.pp 193–198.”
- Binusukumar,k. NagamaniandR. Srinivasa Raghavan (2007) Evaluation of strength at early ages of self-compacting concrete with high volume of fly ash, Construction and building materials, pp 1–8.
- Bouzoubaand Lachemi(2001): Performance of self-compacting concrete made with different volumes of poly propylene fibres, Construction and building materials 55. pp 323–332
- Burak Felekoglu and Hasan Sarikahya(2007) "Effect of chemical structure of polycarboxylate based superplasticizer on workability retention of self-compacting concrete, Construction and building materials, pp 1–9.
- Cengiz Duran Aity(2005): Strength properties of high-volume fly ash roller compacted and workable concrete and influence of curing condition" Cement and concrete research, 35
- ,1112–1121
- Efstratios G. Badogiannis: Durability of metakaolin Self-Compacting Concrete. Construction and Building Materials 2015, PP. 133–141.
- Felekoglu,B. Turkel,S. Baradan(2006) Effect of w/c ratio on the fresh and hardened properties of SCC" Building and Environmental Research vol:35.pp 373–379.
- Girish.R. V.Ranganathand Jagadish Vengala(2010) Influence of powder and paste on flow properties of SCC: "Construction and Building materials 24, Pp2481–2488.
- Graide Zoran, Despotovic, Iva and Topliccuric, Gordana (2008) "Properties of self- compacting concrete
- HebaA.Mohamed(2011) "Effect of fly ash and silica fume on compressive strength of self- compacting concrete under different categories of curing conditions, Shams engineering journal 2:79–86.
- IS: 3812 – 2003, specifications for pulverized fly ash, Bureau of Indian standard New Delhi,India.
- IS:383–1970, Specifications for coarse and fine aggregates from natural sources for concrete,Bureau of Indian standards, New Delhi, India.
- IS:8112 1980, specifications for 43 grade Portland cement, Bureau of Indian standards, NewDelhi, India.
- Khalifa S. Al-Jabri a, Makoto Hisada: Copper slag as sand replacement for high performance concrete, Cement and concrete composites ELSEVIER, 2009, PP.483–488.
- Mehmet Gesoglu, Erhan Guneyisi, ErdoganOzbay(2009) " Properties of self compacting concretes made with binary, ternary, and quaternary cementitious blends of fly ash, blast furnace slag and silica fume" Construction and Building materials 23, pp 1847–1854.
- Meysam Najimi,Ali Reza Pourkhorshidi: Properties of concrete containing copper slag waste. ICE (Institute of Civil Engineers), volume 63, issue 8, 2011.
- Mostafa Khanzadi, Ali Behnood: Mechanical properties of high-strength concrete incorporating copper slag as coarse aggregate. Construction and Building Materials, ELSEVIER, 2009
- Mustafa Sahmaran, Heru Ari Christiano and Ismail Ozgur Yaman (2006) The effect of chemical admixtures and mineral admixtures additives on the properties of self- compacting mortars" Cement and concrete composites, 28. PP432-440.
- Neeta.A, Subha.B, Karthik.V : A Mix Design of Self Compacting Concrete with Copper slag as Fine aggregate and Silica fume as Mineral Admixture. International Journal of Scientific & Engineering Research, Volume 7, Issue 4, April-2016.
- Nikita Gupta and Rafat Siddique, M.ASCE: Sulfate Resistance and Drying Shrinkage of Self- Compacting Concrete Incorporating Copper Slag. ASCE (American Society of Civil Engineers)
No competing interests reported.