This document summarizes a seminar presentation on rice husk ash (RHA). RHA is obtained by burning rice husks between 600-700°C for 2 hours. It is composed primarily of silicon dioxide and can be used to partially replace cement in concrete production. The addition of RHA increases strength and durability by reducing calcium hydroxide levels in concrete. It also reduces efflorescence and susceptibility to chemical and sulfate attacks. Using RHA in concrete can help reduce carbon dioxide emissions from cement production and provides an economic use for the agricultural waste product of rice husks. The seminar outlines the physical and chemical properties of RHA and reviews its advantages and disadvantages when used in concrete.

1. seminar on
RICE HUSK ASH
PRESENTED BY- GUIDE
MOHAMAD MUJTABA HARSHA.D.SAPKAL

2. A valuable green resource with great
potential

3. What is Rice husk ash ( RHA)
Obtained from burning protecting outer cover of rice husk
It consists of non-crystalline silicon dioxide (SiO2) with
high specific surface area and high pozzolanic
reactivity.
The RHA can be found as natural materials, by-products
or industrial wastes
Chemical propertie so fare closer to micro silica ,silica
fime

4. RICE HUSK RICE HUSK
ASH

5. HOW RHA PRODUCE
Chemical compositions of RHA are affected due to
burning process and temperature
RHA produced by burning rice husk between 600 to
700°C temperatures for 2 hours

6. Blaine Specific Surface (cm2/g) 13150
Specific Gravity (cm2/g) 2.21
Mean Particle size (μm) 10.61
Passing # 325 (%) 95.10
Chemical properties
SiO2 90.16
Fe2O3 0.41
Al2O3 0.11
CaO 1.01
MgO 0.27
SÔ3 0.12
Al2O3 + Fe2O3 0.52
SiO2 + Al2O3 + Fe2O3 0.93
Na2O 0.01
K2O 0.65
Table 1 Physical and Chemical Properties of RHA

7. How RHA improves concrete
 OPC reacts with water to form two products
 Calcium silicate hydrate :it gives strength and
durability to concrete
 Calcium hydroxide
 reacts with CO2 causing effloresce
It creates negative effects on concrete

8. Addition of RHA
1.Increases calcium silicate hydroxide
2.Decreases calcium hydroxide
Ca(OH)2+SiO2=H2O+CaSiO3
The major benefits of the reaction are
High strength
Reduced efflorescence
Reduce sulphate attacks
Reduce chemical attacks

9. Uses of RHA
 RHA can be used in the 2 distinct ways
1)To create HPC –RHA can be added to cement to
increase high strength concrete
2)To create Green Concrete-RHA can be used as an
substitute to reduce amount of cement with higher
strength

10. Carbon credits
 The production of 1 Tons of cement contributes to 1
tons of co2 in atmos,
 Worldwide 7% of carbon dioxide emission for
production of OPC
 The utilization of RHA in concrete production is
solution to reduce the cement

11. ADVANTAGES
 Improves compressive strength, flexural strengths
and split tensile strength.
 RHA mixed concrete shows better bond strength as
compared to OPC concrete.
 Permeability of concrete decreases chloride diffusion
and chloride permeation reduces (30%) replacement.
 RHA makes a role to increased resistance to chemical
.

12. DISADVANTAGES
 Suitable incinerator/furnace as well as grinding
method is required for burning and grinding rice husk
in order to obtain good quality ash.
 Strength of concrete is reduced for larger (beyond
30%) replacement.
 There is a little transportation problem.
 Unburnt RHA is not suitable for concrete production

13. CONCLUSION
 To study the effect of RHA as substitute for fine
aggregate in concrete mixture.
 The properties of concrete containing RHA had been
successfully studied.
 The use of RHA in civil construction, besides reducing
the environmental polluters’ factors, may bring several
improvements fotg544r the concrete characteristics.

14. REFRENCE
 1.M.S.SHETTY CONCRETE TECHNOLOGY
 2.Effect of Rice Husk Ash on Cement Mortar and
Concrete. Sudisht Mishra,
Prof (Dr.) S. V. Deodhar.
 3. Effect of Rice Husk Ash on Lime Stabilization. Dr. J. N.
Jha (Member) K. S. Gill
 4.Effect of Rice Husk Ash on Cement Stabilized Laterite.
MUSA ALHASAN