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Physical and Mechanical Properties of Steel Fiber Reinforced Lightweight Aggregate Concrete Using Fly Ash

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 4, Issue 10, October 2014)

596

Physical and Mechanical Properties of Steel Fiber Reinforced

Lightweight Aggregate Concrete Using Fly Ash

Prafull Vijay

1

, Sandeep Singh

2

1,2

School of Mechanical and Building Sciences, Vellore Institute of Technology, Vellore-632014

Abstract--Two different types of Light Weight Aggregates, one with Sodium Hydroxide and another without Sodium Hydroxide were manufactured. Their physical properties were inspected and based on that it was found that Aggregates having sodium hydroxide as their constituent were more dense, high water absorption capacity, smooth texture and were well graded than the aggregates without Sodium Hydroxide as their constituent. Based on these tests, aggregates having sodium hydroxide were chosen for the casting of concrete materials as a coarse aggregate ingredient. Three different mix ratios were taken and two different curing methods were adopted as water curing and hot Oven bath curing. Based on that, six different Mix IDs were formed and different no. of cubes and cylinders were made from those mix IDs. The Compressive test, split tensile test were performed on cubes and cylinders respectively. Based on these tests, it was found that the Specimens of mix ratios with hot oven curing yields better strength than the specimens of same mix ratio with water curing. Different results were analyzed and graphs were drawn.

Keywords - Aggregates, Curing, Split Tensile, Strength, texture, water absorption.

I. INTRODUCTION

Lightweight Aggregate Concrete, expressed as LWAC is not a new thing in concrete technology. LWAC has been known and used since ancient times, so it is not an arduous process to find a good number of references in correlated with the use of LWAC. The ingredients used for manufacturing LWAC are itself from natural aggregates of volcanic origin such as pumice, scoria, etc [1] .It can be seen from the rate of development in the fields of concrete industry and the demand of the lightweight aggregates for manufacturing of lightweight aggregate concrete that this structural element is an ideal choice and can be the future scope of the construction industry. The main thing which makes LWAC advantageous over normal weight concrete is its reduction in the self-weight along with high strength to weight ratio [2].The lightweight aggregates is divided into two categories based on the natural lightweight such as pumice, scoria, etc. and also based on the artificial lightweight aggregates such as fly ash lightweight aggregate, using clay binders etc.

Research studies showed the adequacy of the use of natural and artificial lightweight aggregate concrete having suitable mechanical characteristics for structural applications [3].The advantage behind this research of lightweight aggregate concrete is its lightweight structural design which makes us enable to increase the number of floors and thus having high buildings [4].The formation process of artificial fly ash lightweight aggregate is consist of two techniques namely granulation and compaction. The processing of agglomeration theory was developed in 1940’s [5]. Granulation technique involves in the formation

of solid pellets by addition of light water through sprinklers and further rotating the pellets with the help of pellet machine. Whereas, the compaction techniques involves the formation of pellet and well compacted by using briquettes apparatus for hard pressing. Lightweight aggregate concrete has been successfully produced in the past. However, in terms of mechanical characteristics LWAC were falling apart in some aspects as in compared from natural weight aggregates. The long term sustainability of lightweight aggregates were also in question, the reason behind this is high porosity of the aggregates and high permeability. Researchers have produced however, lightweight aggregate concretes of 50 MPa and above. Also, durability was investigated and in many instances was found to even exceed that of normal-weight concrete

[6,7].Whatsoever it is found that light weight aggregates

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 4, Issue 10, October 2014)

597

II. OBJECTIVE

The basic objective of this paper is:

 To study the efficiency of pellet production of different types of fly ash lightweight aggregate.  To improve the strength properties of addition of

binders.

 To study the physical and mechanical properties of various types of lightweight aggregate.

 To study the mechanical properties of steel fiber reinforced lightweight aggregate concrete.

III. EXPERIMENTAL PROGRAM

Materials

Cement and Flyash

Ordinary Portland cement (OPC) of 53 grade was used to manufacture LWA.The physical and chemical properties of cement were presented in Table 1. The Flyash is class F Flyash which was obtained from Ennore Thermal cement plant was used to manufacture LWA. The physical and chemical properties of Flyash were presented in Table. The content of Flyash used for aggregates was 80% and remaining 20% was Bentonite.

Table 1

Physical & Chemical Properties of Flyash and Cement

Observation Flyash-Class F

Cement

Physical Propeties

Type Class F OPC 53 Grade

Initial & Final Setting

- 45 min & 1Hr & 45 min resp.

Consistency Test - 31 %

Specific Gravity 2.01 3.14

Chemical Properties

SiO2 56.8 18.5

Al2O3 25.8 5.24

Fe2O3 6.8 5.9

CaO 3.67 60.9

MgO 1.67 1.1

SO3 0.47 1.5

Na2O 2.06 -

K2O 0.01 -

Cl¯ 0.52 0.002

Aggregates

Natural sand was used (Zone 2) in the concrete whose average size was 2.36mm sieve size. Coarse aggregate used in concrete was less than 12.5 mm sieve size in surface saturated dry (SSD) condition.

Light Weight Aggregate

Production Technique Of Lwa Using Agglomeration Technique-Cold Bonding

The manufacturing of Lightweight aggregates was done by using Class F Flyash along with addition of Cement and Bentonite using Agglomeration technique (cold bonding). A pelletizer machine shown in Fig 1 was used in the process of manufacturing of aggregates. The disc having dimensions of 500 mm as diameter and 200 mm depth was used.

Fig1. Fabricated disc pelletizer machine

[image:2.612.42.282.434.714.2]
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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 4, Issue 10, October 2014)

598

[image:3.612.55.293.219.556.2]

The duration of rotation was kept for 15 minutes. The aggregates were kept in oven curing at 100° C for 7 days. Table 2 present the composition of LWA manufactured. The gradation analysis of LWA is shown in Fig 2.

Table 2:

Composition Of Pellets Formed

MIX ID C NC

Duration 15 15

Fly Ash (gm) 70 70

Cement(gm) 30 30

NaOH(gm) - 100

Water 25% 25%

Curing Water Curing Hot Oven 200° C

Fig: 2 Gradation Analysis for Light Weight aggregate concrete

Specific gravity and Water absorption of LWA

 Sp (ssd) = ))

 W =

Where, A- Wt. of saturated surface dry Aggregates

W1- Wt. of pycnometer + Wt. of water + Wt. of aggregates

W2- Wt. of Pycnometer + Wt. of aggregates

B- Wt. of Oven Dried Aggregates

Specific Gravity value:-

NC – 2.10 C – 1.78

Water Absorption Value for NC is 1.97 and C is 1.86

Bulk Density of LWA

Bulk Density =

The Bulk density of LWA is presented in Table 3.

Table 3 Bulk density of LWA

Mixing And Casting Of Specimens

Following are the specimens casted for the study:  Lightweight sintered flyash aggregate concrete using

steel fibers with Mix ID 1, curing as water curing and referred as MA1.

 Lightweight sintered flyash aggregate concrete using steel fibers with Mix ID 2, curing as water curing and referred as MA2.

 Lightweight sintered flyash aggregate concrete using steel fibers with Mix ID 3, curing as water curing and referred as MA3.

 Lightweight sintered flyash aggregate concrete using steel fibers with Mix ID 1, curing as Hot Oven Curing at 200°C and referred as MB1.

 Lightweight sintered flyash aggregate concrete using steel fibers with Mix ID 2, curing as Hot Oven Curing at 200°C and referred as MB2.

 Lightweight sintered flyash aggregate concrete using steel fibers with Mix ID 3, curing as water curing and referred as MB3.

Table 4 shows the manufactured mixes according to the cement, coarse aggregates, fine aggregates, amount of super plasticizer and steel amount. The 20 mm steel fiber with an aspect ratio 46 .The types and numbers of specimen casted for this series of test are given below.

Binder

Type

Loose Bulk

Density

Rodded Bulk

Density

C

831.8498

973.873

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 4, Issue 10, October 2014)

599

 15 concrete cubes for testing compressive strength (3, 7&28 days) for each Mix ID and the average values were taken into consideration for test days result.

 4 Cylinder was casted for split tensile (7&28 days) for each mix ID

Table 4

Mixture proportionson the basis of saturated surface dry condition

IV. RESULTS AND DISCUSSIONS

Compressive Strength

The Compressive Strength of the cubes for 3, 7 and 28 days is shown graphically in Fig 4 for each mix ID. From the figure it is evident that MB3 has the highest strength parameter. It is attributed to the fact that as cement content is increasing in the mixes, the bond strength between the particles is increasing and thereby strength is increasing. It was also noticed that as the content of coarse aggregate decreased in the mixes, the strength also decreased. Thus the trend of compressive strength observed in the figure is justified. The compressive test setting apparatus has been shown in Fig 3(i) & Fig 3(ii).

Fig 3(i): Compressive Testing Machine

Fig 3(ii): Testing Apparatus

Split Tensile Strength

The Split tensile strength of the cubes for 7 and 28 days is shown graphically in Fig 5 for each mixes. It is evident from the graph that the split tensile strength also follows the same trend as compressive strength. The observation is attributed the to the increasing cement content which increase the bond strength. The Split Tensile Specimens during test has been shown in Fig 4(i) & Fig (ii).

Ingredient’s ratio M1 M2 M3 Cement 1 1 1

Natural Sand 2 3.45 1.10

Coarse

Aggregates 2.46 2.04 1.81

Water 0.3 0.3 0.3

Steel Fibers (% by volume of concrete)

1.5 1.5 1.5

Super plasticizer (% by weight of cement)

[image:4.612.332.562.128.451.2] [image:4.612.39.269.248.447.2]
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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 4, Issue 10, October 2014)

600

Fig 4(i): Split tensile Testing

[image:5.612.48.282.126.327.2]

Fig 4(ii): Weight Check

[image:5.612.331.563.129.350.2] [image:5.612.113.515.400.612.2]
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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 4, Issue 10, October 2014)

601

V. CONCLUSION

By the analysis of result it can be concluded that:

1) Oven curing is much better than the water bath curing but water curing is more economical. 2) The strength parameters (compressive strength and

split tensile strength) are age dependent as 28 days strength was higher than the 7 days strength.

REFERENCES

[1] Satish CHandra,Leif Berntsson, Lightweight Aggregate

Concrete,Elsevier, 28-Oct-2002 - Technology & Engineering [2] P Gomathi & A Sivakumar, Indian Journal of Engineering &

Material Sciences, Vol.21,April 2014, pp227-232

[3] P. Gomathi and A. Sivakumar,ARPN Journal of Engineering and Applied Sciences,VOL. 8, NO. 4, APRIL 2013,ISSN 1819-6608

[4] Shanmugasundaram S, Jayanthi S, Sundararajan R,Umarani C and

Jagadeesan K. 2010. Study on Utilization of Fly Ash Aggregates in Concrete.Modern Applied Science. 4(5): 44-57.

[5] Baykal G. and Doven A.G. 2000. Utilization of Fly Ash by Pelletization Process Theory Application Areas and Research results. Resources, Conservation and Recycling. 30, 59-77.

[6] G.C. Mays, R.A. Barnes, The performance of lightweight

aggregate concrete structures in service, The Structural Engineer 69 (20) (1991) 351–361.

[7] M. Berra, G. Ferrara, Normal weight and total-lightweight high strength concretes: A comparative experimental study, in: Proc. of High-Strength Concrete 2d Int. Symp., ACI, SP-121, 1990, pp. 701–733.

Figure

Table 1     Physical & Chemical Properties of Flyash and Cement
Table 2:  Composition Of Pellets Formed
Fig 3(i): Compressive Testing Machine
Fig 4(i): Split tensile Testing

References

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