EFFECT OF RICE HUSK ASH ON THE STRENGTH AND DURABILITY PROPERTIES OF CONCRETE

NATIONAL INSTITUTE OF TECHNOLOGYAGARTALA

DEBASREE GHOSH JUNIOR ENGINEER (CIVIL DEPT)WORK OF 2014-8TH SEM

Chapter:1- Introduction Chapter:2- Objective Chapter:3- Literature Review Chapter:4- Material Properties Chapter:5- Experiments required to observe the effect Chapter:6- Observation Chapter:7- Conclusion. Chapter:8- Future Scope References

CONTENTS:

Concrete is the most vital material in the modern construction.

RHA (RICE HUSK ASH) Concrete is the special type of concrete, that

are produced by unusual techniques. Concrete is by definition a

composite material consisting essentially of a binding medium and

aggregate particles with definite proportion of water and it can take

many forms.

RHA Concrete do have advantages as well as disadvantages. The

character of the concrete is determined by quality of the paste. That is

its workability.

Chapter:1-INTRODUCTION

Cont…

CONCRETE

COARSE AGGREGA

TE

FINE AGGREGA

TE

BINDING MATERIA

L

1.1 HOW CONCRETE FORMS:

WATER

Cont…

CEMENT

LIME

LIME-CEMENT

1.2 DESCRIPTIVE DIAGRAM

BINDING MATERIAL

COARSE AGGREGA

TE

STONE

BRICK CHIPS

Cont…

SANDSTON

E DUST

RHA

SURKHICINDER

FINE AGGREGATE

Cont…

Effect of Rice Husk Ash depends on the amount of

replacement and on the chemical and physical

characteristic of replaced material.

Here we will introduce Rice Husk Ash as a replacement of

Fine aggregate with different percentages.

Investigations for the requirement of water for different

percentages of RHA, amount of replacement and the

change in the behaviour of concrete is done.

During the milling of paddy about 22 % of the weight of

paddy is received as husk. This husk is used as fuel in the

rice mills. This husk contains about 75 % organic volatile

matter which burns up and the balance 25 % of the weight

of this husk is converted into ash during the firing process,

which is known as rice husk ash (RHA).

It is highly reactive in nature and obtained by combustion

process.

1.3 Rice Husk Ash (RHA)

Cont…

It is a part of waste ashes. The landfill of waste ash is a

problem of environmental effects because these waste ashes

are not used in any work without construction.

It is a green house agent and increases the green house effect

adversely and becomes non-eco friendly. Many researches

had been done to find out its solution.

Cont…

What we should do?

As Rice Husk Ash Is Non- Eco Friendly

LET US OBSERVE BY EXPERIMENTAL WAY

RHA has two roles in concrete manufacture, as a substitute

for fine aggregate, reducing the cost and weight of concrete

in the production of low cost building blocks.

Therefore, a large number of researchers have been directed

toward the utilization of waste materials.

It increases the durability of concrete.

Chapter:2- OBJECTIVE

Cont…

Rice Husk Ash (RHA) is an agricultural waste product, and

how to dispose off it is a problem to waste managers. Use of

RHA reduces this type of problems.

As it is a waste form in environment there is an increasing

importance to preserve the environment in the present day

world. RHA from the parboiling plants is posing serious

environmental threat and ways are being thought of to

dispose them.

Cont…

Therefore some research work has been done and found that

RHA can be used in construction purpose as a replacement

for cement and sand.

The concrete material is the expensive material and used in

all over India, if all-important expensive material is partially

replaced with more natural, local and affordable material like

RHA will not only take care of waste management but will

also reduce the problem of high cost of concrete and housing.

Cont…

RHA can be used for low cost building (say less important

building specially). But in some specified amount of RHA can

be used.

It is also found that RHA, fly ash with some steel fibre shows

better strength properties than normal concrete.

By using this Rice husk ash in concrete as replacement, the

emission of green house gases can be decreased to a greater

extent.

From the Indian Concrete Journal (ICJ), Journal of

Cement and Concrete Research, Journal of Advanced

Cement based Materials, American Concrete Institute

(ACI) publications literature review has been obtained.

It gives the brief idea about the effect of different types of

ashes on concrete when it is replaced in the place of sand

or cement.

Chapter:3- LITERATURE REVIEW:

Cont…

Different researcher gives their opinion about the

replacement of RHA.

◦ Aramraks et al., (2006) did some experimental study to find out the

feasibility of using ash as fine aggregate in structural grade concrete

through the investigation of the physical and mechanical properties

of concrete in fresh and hardened state.

◦ Aggarwal et al., (2007) studied the effect of use of ash for various

percentages (0-50%) replacement of fine aggregates with ash can

easily equated to the strength development of normal concrete at

various ages.Cont…

◦ Kasemchaisiri et al., (2008) presented the test results of fresh

concrete, the use of ash resulted in the reduction of compressive

strength due to increase of porosity of hardened concrete.

◦ Rocha et al., (2009) investigates the influence of ash as a

replacement for FA, the result shows ash are susceptible to water loss

by bleeding and the higher the percentage of ash used as a natural

sand replacement the lower the deformation through plastic

shrinkage.

Cont…

◦ Lee et al., (2010) evaluated the utilization of ash as FA and CA in

high-strength concrete. It was found that the slump flow of fresh

concrete was slightly decreased from 530mm to 420mm when coarse

ash was replaced 100% of normal CA, while fine ash did not affect the

slump flow.

◦ Chua Wei Leong et al., (2010) studied the use of municipal solid

waste (MSW) incineration ash as aggregate for the production of light

weight concrete, the compressive strength s of concrete in the three out

of the four test series were able to achieve the ASTM standard

requirement on light weight concrete.Cont…

◦ Sun et al., (2008) applied low-profile piezoceramic transducers and it

shows the differences in amplitude between wave packets are sensitive

to the cracking process of concrete with externally applied loads.

Literature review is important to have the knowledge of

amount of replacement and its requirement.

It gives some co-relationship between different form of

replacement that has been observed during experiments of

different researchers.

Physical State

Appearance Particle Size

Color Odour Specific Gravity

Solid – Non

Hazardous

Very fine powder

25 microns

Grey Odourless 1.22

Chapter:4- MATERIAL PROPERTIES:

Rice husk ash is pozzolanic material and highly reactive.

RHA is high in silica content in the form of noncrystalline or

amorphous material silica.

It is also durable in nature, several researchers have studied the

durability variation of the concrete with pozzolanic materials.

Rice Husk Ash: 4.1 TABLE

Cont…

After replacement of Fine aggregate with RHA we have the

following proportions for M20 grade concrete with different

percentages of Fine Aggregate replacement with RHA are as

follows:-

% Cement Fine aggregate

Coarse Aggregat

e

RHA

20% 1 1.08 2.66 0.1340% 1 0.81 2.66 0.2660% 1 0.54 2.66 0.39

4.2. TABLE

Compressive Strength Test on:◦ Cube (150mm x150mm x 150mm)◦ Cylinders (150mmØ x 300mm)

Split Tensile Strength Test on:◦ Cylinders (100mmØ x 200mm)

Flexural Strength Test on:◦ Beam (100mm x 100mm x 500mm)

Rapid Chloride permeability Test Young’s Modulus Test Non-Destructive Test

Chapter:5- Experiments Required To Observe The Effect Of RHA

Cont…

The strength of the concrete

depends on the properties and

proportions of the constituent

materials, rate of loading, the

method of testing and the

specimen geometry.

The cube specimen generally

exhibit 20 to 25 percent higher

strength than cylindrical specimen

due to specimen geometry.

Compressive Strength Test:

Cont…

The split tensile strength test is the

indirect measurement of the tensile

strength by placing a cylindrical

specimen horizontally between the

loading surfaces.

This method is consists of applying a

diametric compressive force along the

length of a cylindrical specimen.

Split Tensile Strength Test

Cont…

Flexure strength test is the ability check

of a beam or slab to resist failure in

bending.

Generally flexure strength value is

about 2 to 20 percent of compressive

strength.

The flexure strength of the specimen is

expressed as the modulus of rupture fb.

Flexural Strength Test on:

Cont…

Rapid Chloride Permeability Test

Rapid chloride permeability Test has been conducted

to find out the permeability of different concretes.

Rapid chloride test was designed to determine the

resistance of concrete to the penetration of chloride

ions, an indicator of its permeability.

Charge passed (coulombs) Chloride ion penetrability

>4000 High

<100 NegligibleCont…

The elastic modulus of concrete is a very

important mechanical parameter reflecting the

ability of the concrete to deform elastically.

The modulus of elasticity or Young’s modulus

is defined as the slope of the stress-strain curve

within the proportional limit of a material.

The secant modulus is defined as the slope of

straight line drawn from the origin of axes to

the stress-strain curve

Young’s Modulus Test

Cont…

For Non-Destructive Test, piezoelectric

transducers and Ultrasonic Pulse Velocity

Method have been used to find out the crack

depth for conventional concrete and rice

husk ash concrete.

The basic principle of crack detection is that,

if the crack is at appreciable width and

considerable depth, perpendicular to the test

path, no signal will be received at the

receiving transducer.

Non-Destructive Test

COMPRESSIVE STRENGTH OF CONCRETE CUBE WITHOUT RHAFIG.1 Compressive strength of M20 grade concrete cube (N/mm2)

Chapter:6- OBSERVATION

1day 3days 7days 28days020406080

100

13.6 14.82 23.2 25.4514.22 14.6821.5 25.3113.72 15.522.5

27.83

Series1 Series2 Series3Cont…

COMPRESSIVE STRENGTH OF CUBE WITHOUT RHAFIG.2 Compressive strength of M25 grade concrete cube (N/mm2)

1day 3days 7days 28days0102030405060708090

100

14.95 15.83 26.23 29.5615.26 15.66

25.4632.4517.72 18.21

24.3328.23

Series1 Series2 Series3Cont…

COMPARISON BETWEEN DIFFERENT BEHAVIOUR OF CONCRETE  

FIG. 3 Compressive strength of concrete cube without RHA(N/mm2)

FIG. 4 Compressive strength of concrete cube with RHA(N/mm2)

1 day 3 days 7 days 28 days

13.85 15

22.42

26.2

15.98 16.57

25.3430.08

M20 M25

1 day 3 days 7 days 28 days

8.0312.6

15.72

20.819.17

13.217.16

22.44

10.49

14.7

18.12

22.8

M20 with 60% RHA M20 with 40% RHAM20 with 20% RHA

Cont…

FIG. 5 Compressive strength of M20 grade concrete cube with RHA(N/mm2)

1 day 3 days 7 days 28 days

8.03

12.6 15.72 20.819.17

13.217.16 22.44

10.49

14.7

18.1222.8

13.85

15

22.42

26.2

Comparison between M20 grade without RHA and with 20% , 40% & 60% RHA

M20 with 60% RHA M20 with 40% RHA M20 with 20% RHA M20

Cont…

M25 M20 20% RHA 40% RHA 60% RHAWithout RHA M20 With RHA

0

5

10

15

20

25

30

35

23.22

18.0315.78

14.0711.9

31.83

24.15

19.4

13.83

10.72

28.34

20.17

16.76 14.76

13.47

Specimen 1 Specimen 2 Specimen 3

COMPRESSIVE STRENGTH REPRESENTATION OF CYLINDERS

FIG. 6 Total Compressive Strength of cylinder in N/mm2

Cont…

FIG. 7 Total representation of Split tensile Strength of cylinder in N/mm2

TOTAL REPRESENTATION OF SPLIT TENSILE STRENGTH 

M25 M20 20% RHA 40% RHA 60% RHAWithout RHA M20 With RHA

2.74

1.92

1.67

1.43

1.18000000000001

2.322.09

1.731.57

1.24

2.41

2.13

1.79

1.391.15999999999999

2.49

2.05

1.73

1.46

1.19000000000001

Specimen 1 Specimen 2 Specimen 3 Average

Cont…

FIG. 8 Flexural strength of beam (100mm x100mm x500mm)

FLEXURAL STRENGTH OF BEAM WITH AND WITHOUT RHA

Strength a Strength a Strength aM20 M25 M20 (20% replacement)

Without RHA With RHA

0

5

10

15

20

25

30

The concrete specimen so prepared gives the highest

compressive strength at 7days compared to 1day and 3days.

The compressive strength of concrete varies with the type of

curing and the amount of curing done before the test.

Experimentally it is found that 28 days strength is found to

be more than 7 days.

RHA replacement, M20 with 20% replacement shows higher

strength values than M20 with 40% replacement.

Chapter:7- CONCLUSION:

Cont…

M20 with 40% replacement shows higher strength values

than M20 with 60% replacement. But three of these values

are found lesser strength than the specimens tested without

rice husk ash replacement.

Use of RHA showing a drastic increase in the amount of

water required during the preparation of specimens.

Standard mixes of concrete uses less amount of water as

compared to the mixes replaced with rice husk ash.Cont…

We can conclude that in cases of lack of fine aggregate we

can use rice husk ash in place of fine aggregate up to a

certain extent.

It increases the porosity of concrete specimen and hence

decrease the strength of concrete, but lesser amount of

replacement will show very negligible change in the

strength, so in case of having shortage of fine aggregate we

can use some amount rice husk ash.

In future, the availability of rice husk ash as a replacement

for fine aggregate can be used if the properties of rice husk

ash concrete are similar to standard concrete.

Rice Husk Ash decreases the workability of concrete as the

water requirement increases. But if we use RHA, Fly ash

with some steel fiber, it will increase the strength of

concrete. Hence, can be used as a normal concrete in

future.

Chapter:8- FUTURE SCOPE:

[1] Assumed standard deviations for target mean strength

of concrete taken from table 11, 22 page no. 491-492 of

CONCRETE TECHNOLOGY by M.S. Shetty.

[2] Mix proportions according to IS: 456-2000

[3] Mix design as per IS: 10262-2009

[4] Aggregates in Concrete. Asian Journal Of Civil

Engineering (Building And Housing) Vol. 8, No. 1 (2007)

Pages 49-62.

References:

Cont…

[5] Qasrawi H.Y., Marie I.A., The use of USPV to anticipate failure in

concrete under compression. Cement and Concrete Research 33 (2003)

2017–2021. [6] Kasemchaisiri R., Tangtermsirikul S., Properties of Self-Compacting

Concrete in Corporating Ash as a Partial Replacement of Fine Aggregate.

ScienceAsia 34 (2008): 087-095.

[7] Kim H.K.,Use of power plant ash as fine and coarse aggregates in

high-strength concrete.

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