This document discusses the use of rice husk ash (RHA) in concrete. RHA is a pozzolanic material that is produced from burning rice husks, an agricultural waste. RHA has physical properties like gray color, irregular texture, and particle size less than 45 microns. Chemically, RHA is high in silicon dioxide at 86.96% and can partially replace cement in concrete production. Using RHA in concrete provides benefits like higher strength, reduced permeability, and increased resistance to sulfate and chloride attacks. Graphs show increased compressive strength of RHA concrete at 7, 14, 21, and 28 days. While water requirements are increased, RHA can be a good substitute for cement and help

1. USE OF RICE HUSK ASH IN CONCRETE (RHA)
Presented by :-
G . Tharunkumar
Dept. Of Civil Engineering,
G. Pullaiah College of Engineering and Technology.

2. CONTENT
 1 Introduction
 . What is RHA
 3. Properties of RHA
 4. RHA in Concrete Production
 5.Advantages and Disadvantages
 6.Conclusion

3. 1.INTRODUCTION
 Rice husk is an Agricultural waste product which is produced in Millions
of tons. Approximately for 100Kg of rice ,20Kg of rice husk is obtained .
Rice husks contain Organic substance and 20% of Inorganic material.
 Physical characteristics and chemical composition of mineral admixtures
can be fulfilled by burning rice husk into RICE ASH.
 Combustion of rice husk at controlled temperature produces RHA that has
amorphous silica content and large surface area.

4. 2.What is RHA ?
 Rice husk is an “pozzalonic material” . It is having different types of
physical & chemical properties . The product obtained by from RHA is
identified by trade name silpoz which much finer than cement.

5. 3a.Physical properties of Rice Husk Ash:-
S.no Particulars properties
1 Colour Gray
2 Shape Texture Irregular
3 Mineralogy Non Crystalline
4 Particle Size <45micron
5 Odour Odourless
6 Specific gravity 2.3
7 Appearance Very fine

6. 3b.Chemical properties:-
S.no Particulars Proportio
n
1 Silicon dioxide
(sio2)
86.96%
2 Aluminium oxide (Al2o3) 0.2%
3 Iron oxide
(Fe2o3)
0.1%
4 Calcium oxide
(cao)
0.3-2.2%
5 Magnesium oxide (Mgo) 0.2-0.6%
6 Sodium oxide
(Na2o)
0.1-0.8%

7. 4. RHA in Concrete production
a. In convectional concrete:
 As RHA contains high amount of amorphous
silica .It is can be used as a partial replacement
of cement in convectional concrete to develop its
strength and durability properties.
 The RHA will be perfect substitute of silica
fume for making special concrete mixes.
 From experiments it is found that replacement of
RHA below 20% in concrete gives neither
gives strength in concrete nor durability

8. 5. Advantages
• Higher the strength as it provides an additional CSH
Gel.
• Reduces permiability hence resistance against the
chloride attack increases.
• As it consumes lime content of the concrete , Sulfate
attack doesn’t attack.
• The bleeding of concrete doesnot occur’s

10. Compressive strength of RHA Concrete
 The compressive strength of RHA concrete
was investigated at 7,14,21,28 days curing
age.
 The summary of this result are graphically
represented Graphically below for
percentages of RHA

11. Graphical representation

12. Disadvantages
 The water for convectional concrete is increased.
 Choice of good quality RHA which is major factor
for strength and durability.
 We cant use only RHA as a source of Materialin
Geopolymer concrete.

13. 6.Conclusion
 The RHA is very good substitute of cement in both
convectional concrete and in Geopolymer concrete.
 The RHA can be used as a good pavements for improving the
shear strength of pavements.
 Use of RHA helps in reducing the co2 emission,
creating a better environment controlling Global warming

14. As a Civil Engineer ,I request
all you to use eco-friendly
materials and help in creating
A better environment