The document discusses the use of rice husk ash (RHA) as a supplementary cementitious material (SCM) in concrete. RHA is a waste product from rice production that can be used to partially replace cement in concrete. Using RHA provides environmental benefits as it utilizes an agricultural waste and reduces cement usage, which is responsible for 7% of global CO2 emissions. The document outlines the properties and pozzolanic reactivity of RHA that make it suitable as an SCM. Test results showed improved compressive strength of concrete when partially substituting cement with RHA. This demonstrates the potential for RHA to enhance the sustainability and properties of concrete.

1. PRESENTAED BY:
Saibas .S
Civil Engineering
J.N.N.C.E-Shimoga

2.  Today, concrete has become the most commonly used
building material in the construction industry.
 Currently, concrete is extensively used with more than 10
billion tons produced annually in modern industrial
society.
 For manufacturing that quantity of concrete, the concrete
industry has had an enormous effect on the
environmental appearances.
 The cement industry alone is estimated to be responsible
for about 7% of all the CO2 generated worldwide.

3.  Several studies have focused on finding alternatives that can be used
as replacement to cement, such as, the disposable and less valuable
wastes from industry and agriculture wastes.
 The utilization of agricultural waste can provide the break-through
needed to make the industry more environmentally friendly and
sustainable.
 The purpose of this study is to clearly describe and briefly introduce
waste materials from agricultural commodities that have been well
managed and successfully used as supplementary cementitious
materials (SCM) for the manufacture of concrete.
 Among all agricultural wastes , the Rice Husk ash proves to be
effective, used as Supplementary cementitious Materials.S

4. Cementitious material, supplementary, (SCM) -
an inorganic material that contributes to the
properties of a cementitious mixture through
hydraulic or pozzolanic activity, or both
Some examples of supplementary cementitious
materials are rice husk ash, fly ash, silica fume,
slag cement, and natural pozzolans. In practice,
these materials are used in combination with
portland cement.

5.  Nowadays, global environmental warming is considered to be the
most important worldwide issue.
 As agricultural wastes affect of the environment, the use of these
waste materials in construction will realize the many benefits
previously mentioned.
 Research has determined that concrete that produced using
agricultural wastes presents improved thermal properties, which
can result in significant points being gained in the atmosphere.
 Agricultural wastes used as SCMs in concrete production can
contribute to the environmental friendliness and economic
effectiveness of structures worldwide.
 Rice husk ash is most commonly used agricultural waste as SCM
in production of concrete.

6. Rice husk is a natural sheath that forms around rice grains during
their growth. It is widely available in rice-producing countries, and
considered to be an agricultural solid waste material.

7. Rice husk has no commercial value when removed
during the refining process.
Rice Husk Ash was burnt for approximately 72hours
in air in an uncontrolled burning process. The
temperature was in the range of 400-600 degree C .The
ash collected was sieved through BS standard sieve size
75µm and its colour was grey.

8. Country
Rice paddy
production in
2013(Mt)
Husk produced
(20% of total)
(Mt)
Potential ash
production
(18%of husk)Mt)
Rice paddy
production in
2002(Mt)
Incremental
(%) from 2002
to 2013
China
200.0 40.0 7.20 177.60 11.20
India
160.0 32.0 5.80 123.0 23.10
Bangladesh
45.0 9.0 1.60 39.0 13.30
Pakistan
9.0 1.80 0.30 5.80 35.50

9.  Rice husk ash (RHA) is a carbon neutral green product
gained from raw rice husk that is changed to ash using the
combustion process.
 The colour of the rice husk ash (RHA) ranges from white
grey to black, depending on the source of the raw material,
method of incineration, time and burning temperature.
 RHA is very rich in silicon dioxide which makes it very
reactive with lime due to its non-crystalline silica content
and its specific surface. It has about 85-90% silica.
 This study investigated the engineering properties of
RHA as a material for concrete production. The results
shows that RHA is a super pozzolan and very suitable as a
partial replacement of OPC.
 i.Physical Properties ii. Chemical Properties

12. • A pozzolan is defined as ‘‘a siliceous or siliceous and aluminous
material, which in itself possesses little or no cementitious value but
will, in finely divided form and in the presence of moisture,
chemically react with calcium hydroxide to form compounds
possessing cementitious properties (pozzolanic activity)’’.
• It can be explained that when pozzolanic materials are combined
with Portland cement, they will react to form cementitious
properties, whereas by themselves, they do not possess any
cementitious properties.
• The RHA is considered as a good super-pozzolona material in
the production of concrete due to its high silica content.

13.  The use of RHA as a supplementary cementitious material for
producing high strength concrete.
 Most studies have indicated that the standard compressive
strength of concrete combined with or without SCMs, is within the
range for conventional concrete (15–45 Mpa) and has a density of
about2400 kg/m3 .
 Recent studies have shown the possibility of producing high
strength concrete up to 55 MPa and72 MPa for 7 and 28 days
curing , respectively.
 Promoting the compressive strength of concrete and the
ability to produce high strength concrete with SCMs, such as
RHA, is very important because the compressive strength of
concrete plays a fundamental role in the design and
construction of concrete structures .

14. SEM morphology of the RHA powder

15. The compressive strength of RHA concrete was investigated
at 7 ,14 ,21,28 days curing age. The summary of the results
are presented graphically and tabulated in a figure 1 and 2
below for the percentages of RHA.
0
5
10
15
20
25
30
RHA 20%
WITHOUT
RHA
7 DAYS
14 DAYS

17.  Recent interest focused on sustainable development
and the recognition of eco concrete with the
population growth around the world.
 The technical and economic advantages of
incorporating Rice Husk Ash in concrete should be
exploited by the construction and rice industries,
more so for the rice growing nations of Asia.
 As the Rice Husk Ash is waste material, it reduces
the cost of construction.

18.  RHA based sand cement block can significantly reduce
room temperature. Hence air conditioner operation is
reduce resulting in electric energy saving.
 The utilization of agricultural waste can be the break-through
needed to make the industry more environmentally friendly
and sustainable.
 The successful usage as a partial or whole replacement of
Portland cement contributes to the resolution of the land fill
problem and reduction in the cost of building materials, and
provides a satisfactory solution to environmental issues and
problem associated with waste management.

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[3] Zain .M.F.M, Islam .M.N, Mahmud .F and Jamil .M,
Production of rice husk ash for use as a in concrete Constr
Build Mater supplementary cementitious material 2011,
p.798–805
[4] Mahmud .H.B, Chia .B.S and Hamid .A.A, Rice husk ash –
an alternative material in producing high strength concrete.
In: Proceedings of international conference on engineering
materials, Ottawa, Canada; 1997. p. 275–284.