The document discusses utilizing sewage sludge ash in construction materials. It begins by introducing that sewage sludge obtained after treatment is currently used for landfills, soil conditioning, and fertilizer. The objectives are to effectively manage sludge by using incinerated ash in construction. Literature shows sludge ash can replace 20-40% of clay in bricks and a small ratio of ash can replace cement in concrete. The methodology examines collecting sludge, testing dried and incinerated sludge properties, and incorporating ash into bricks, concrete, and pavers. Preliminary results found the ash bricks absorb more water and concrete with 20-40% ash reached 16-18 MPa compressive strength. The document concludes that alternative

1. Utilisation of Sewage Sludge Ash
in Construction materials
PROJECT GUIDE:
Dr. T. MURALI KRISHNA
EXTERNAL GUIDE:
Mr.R. RAMACHANDRAN
BY
M.ABILASH (11310103002)
K.AJITH (11310103005)
AR.SASANK (11310103006)
MA.NETHAAJE (11310103029)

2. INTRODUCTION
 Sewage Sludge is that obtained after the
treatment of sewage from sewage treatment
plant (STP)
 The present scenario is that this treated sludge is
used for land fills (open and closed), soil
conditioner and natural fertilizer.
 Most of the city and towns the sewage disposal is
not proper, improper disposal of this treated
sludge will cause environmental problems like,
 Seepage of gray water into the ground water etc.,

3. OBJECTIVES
Effective management of the sludge is a
challenging problem . Main objective of our project is to
utilize the sewage sludge in making construction
materials by incinerating sludge

4. LITERATURE REVIEW
Sludge ash in clay bricks :
The appropriate percentage of ash content for producing
quality brick was in the range of 20 to 40 %
The optimum moisture content is in the range of 15 to 20%
The molded mixture is fired at 1000 degree Celsius for 6
hours.
Sludge in concrete :
The chemical component of the incinerated ash of sewage
sludge is close to the component of cement used in
concrete.
If we use small ratio of sewage sludge ash(SSA) we can
produce good ordinary Portland cement (OPC).
If we increase the ash content in the cement due to its
porosity we can make pervious concrete.

5. METHODOLOGY
Flowchart for Experimental Procedures for clay bricks
Dewatered Sewage Sludge
End product
105 o
C Oven Dry Incinerate at 800 o
C
Determine sludge and Ash Characteristics
Crushed Clay Prepare Brick Mixtures 0 % - 50 % Ash
Analyse:
Specific Surface Area,Atterberg’s test,Compaction test
Vacuum out Air from the mix.Extruded into Standard ModesMaturated for 24 hrs
then 103 o
C oven dry
Fired at 950 o
C, 1000 o
C, 1050 o
C
Building Brick Tests:
Firing Shrinkage, Loss on Ignition, Water Absorption,
Bulk Density, Compressive Strength

6. WORK DONE
 Collecting sewage sludge from STP
 Testing the properties of dried sludge
 Incinerating the dried sludge
 Testing the properties of sewage sludge ash
 Particle size distribution of sludge ash
 Preparing the clay bricks
 Ash in clay bricks
 Ash in concrete
 Ash in pavers blocks

7. COLLECTING SEWAGE SLUDGE
FROM STP
Sewage sludge is collected from Koyambedu
Sewage treatment plant.
The collected sludge is from the first drying bed of
the STP.
The moisture content of the collected raw sludge is
5.27% so the sample is dried under the natural heat
(sun light) for two days.
As the sample collected from STP is in the form of
cakes is has bee pulverized to completely dry the
sludge

8. PROPERTIES OF DRIED
SLUDGE
 No harmful emissions are identified since sludge
is used for agricultural purpose as natural
fertilizer.
 But ,testing of raw sludge is necessary before
incinerating the sludge.
 Harmful emissions are found once the sludge is
incinerated.

9. INCINERATING THE SLUDGE
 Sludge has to be incinerated at an temperature of
850 to 900 degree Celsius, so there has to be a
closed conduit.
 This type of incinerators available only in industries
 We incinerated our sewage sludge in bio-gas
incinerator which can produce a maximum
temperature of 1000 degree Celsius.
 We made separate tray made of mild steel (MS) of
size 6*2ft.
 The efficiency of incinerator for our sludge is 70%

10. INCINERATOR INCINERATED
ASH

11. PROPERTIES OF SLUDGE
ASH
• The main aim of our project is to reduce the
contamination made by the sewage sludge, so the
sludge ash is tested for the presence of toxic
elements
• We tested the sludge properties, the results shows
the toxic elements are with in the limit
• The test results shows the presence of heavy
metals which causes leaching effects are in the
trace level

12. PARTICLE SIZE DISTRIBUTION
 As the sludge collected from the STP is a mixture
of sand particles with sludge, it has to be fine
sieved.
 Sieve used for particle size distribution
 For Brick 0.850mm (Pass through) ASTM
20
 For Concrete 0.212mm (Pass through)
ASTM 70

13. PREPARING THE CLAY BRICKS
 Weight of fresh Brick : 4.4kg
 Weight of a well dried brick (Nil moisture) : 3.4kg
 Water content : 4.4-3.4 = 1000gms = 1ltr
 Approximately 800ml water is used for a clay brick
PROPORTIONS
Percentage of
ash
Weight of Mud Weight of ash
% grams grams
30 2380 1020
40 2040 1360
50 1700 1700

14. CASTED SEWAGE SLUDGE
ASH BRICK

15. FIRING OF CLAY BRICKS

16. TESTS ON FIRED CLAY
BRICKS
S.
N
Ash %
in brick
Weight of
clay
Brick(kg)
(a)
Weight of
fired
bricks(Kg
(b)
Loss on
Ignition
(Kg)
(c)=
(a)-(b)
Weight of
water
absorbed
brick (Kg)
(d)
Differenc
in weight
(kg)
(e)=
(d)-(b)
1 NIL 3.600 3.396 0.204 3.940 0.544
2 30 % 3.000 2.790 0.210 3.333 0.543
3 40% 2.810 2.572 0.238 3.442 0.870
4 50% 2.730 2.418 0.312 3.542 1.394

17. SLUDGE ASH IN CONCRETE
Properties of Sludge Ash:
Name of the Parameters Protocol Unit Result
Total Kjeldhal Nitrogen as
N
14684 1999 (Reaff.2005) % 0.30
Phosphorus as P 14684 1999 (Reaff.2005) % 1.1
Potassium as K EPA 3050 B % 0.14
Mercury as Hg EPA 1311 mg/kg BDL(DL:5.0)
Cadmium as Cd EPA 3050 B % 0.27
Arsenic as As EPA 3050 B mg/kg BDL(DL:5.0)
Lead as Pb EPA 3050 B % 0.01
Chromium as Cr EPA 3050 B % 0.005
Nickel as Ni EPA 3050 B mg/kg 45.9
Manganese as Mn EPA 3050 B % 0.043
Copper as Cu EPA 3050 B % 0.177
Iron as Fe EPA 3050 B % 2.29
Calcium as Ca EPA 3050 B % 5.59

18. Properties of sludge:
Name of the Parameters Protocol Unit Result
Moisture IS 2720 Part 2 1973 % 5.08
Total Kjeldhal Nitrogen as
N
14684 1999
(Reaff.2005)
% 0.32
Phosphorus as P
14684 1998
(Reaff.2005)
% 0.93
Potassium as K USEPA 3050 B % 0.83
Cadmium as Cd USEPA 3050 B % 0.32
Arsenic as As USEPA 3050 B % 0.003
Lead as Pb USEPA 3050 B % 0.01
Chromium as Cr USEPA 3050 B % 0.006
Nickel as Ni USEPA 3050 B mg/kg 61.4
Manganese as Mn USEPA 3050 B % 0.041
Copper as Cu USEPA 3050 B % 0.23
Iron as Fe USEPA 3050 B % 11.28
Calcium as Ca USEPA 3050 B % 5.7

19. REACTION IN CEMENT AND
ASH MORTAR
Results from FTIR

20. Ash % in concrete
 The presence of Calcium as Ca in sludge ash prompted
us to replace cement partially in concrete.
 Grade of the concrete is M20
 Water Cement ratio is 0.6
 The proportion of ash added is 20%,30% and 40% to
the cement.

21. CASTED,ASH MIXED CONCRETE
CUBES

22. COMPRESSIVE TEST
Sl.N
o
Grade of
concrete
Percentage of
ash
Compressive strength
(KN/mm sq.)
1 M20 20 % 18.7
2 M20 30 % 16.6
3 M20 40 % 16.4

23. REACTION BETWEEN CEMENT
AND ASH
S.N
o
Percentage
Ash in
Mortar
Calcium
Silicate
Hydrate
(g/Kg)
Calcium
Hydroxide
(g/Kg)
Ettringite
(g/Kg)
Mono
Carbonate
(g/Kg)
1 NIL 18.68 2.0 11.34 25.85
2 20 % 6.32 0.67 14.58 24.63
3 30 % 5.10 0.54 16.77 23.45
4 40 % 6.96 0.76 15.12 22.81

24. IMPORTANCE OF HYDRATION
 Calcium silicate hydrate, this is the main reaction product and is
the main source of concrete strength.
 Calcium hydroxide contributes slightly to the strength and
impermeability of the paste, because it reduces the total pore
volume by converting some of the liquid water into solid form.
 Ettringite is formed in hydrated Portland cement system as a
result of the reaction of calcium aluminate with calcium sulphate,
both present in Portland cement

25. ASH IN PAVER BLOCKS
 Mix Grade used for paver block is M40.
 Normal procedure of making paver blocks is adopted
 80 mm zigzag blocks are casted.
 Cement in pavers are replaced by 20%,30% and 40% with
sludge ash.

26. PERVIOUS NATURE OF PAVER
BLOCK

27. PASSIVATION
 The presence of nickel as Ni is 45.9 % in our
sludge ash.
 Nickel can be used for handling elemental
fluorine, owing to the formation of a passivation
layer of nickel fluoride.
 By devising some technique , the reinforcements
inside the structures can be prevented against
corrosion by using Nickel in sludge ash.

28. Feasibility
Incineration is a good process by which all toxicities can be
eliminated. But by incineration the emission of toxic gases
are at higher rate. These toxic gases can be decrease by
using the following methods,
 Closed chamber incineration .
 ESP (Electrostatic Precipitators) in incinerators.

29. Conclusion
 Ash in clay bricks: Loss on Ignition (LOI) is on higher
side . so alternative procedure is needed to use sludge
ash in clay brick.
 Ash in Concrete: From sludge ash having smaller
sized grains, denser concrete can be made, when
cement is replaced.
 Ash in paver blocks: Use of quarry dust and sludge
ash made paver blocks pervious attaining same
properties as normal blocks.

30. THANK YOU