1. COMPRESSIVE STRENGTH OF CONCRETE USING SAWDUST AS FINE AGGREGATE
Submitted by
Chella Meena.D
Kokila.L
Saraswathy.AN
Guided By
Mr.K.Letcham M.E.,
Assistant Professor(Senior Grade) / Civil

2. ABSTRACT
This project reports the results of an experimental investigation carried out to study the effects of sawdust on strength development of concrete .
Fine aggregate is partially replaced with 10, 15 and 20% of sawdust by weight.
A total of 24 cubes of 100mm dimensions are cast and cured in water for 7 and 28 days.

3. OBJECTIVES
To find the compressive strength of concrete using the sawdust as fine aggregate with the concrete of grade M20.
The effect of cementious materials & curing condition on the compressive strength of concrete also analyzed for a period of 7 & 28 days.

4. LITERATURE SURVEY
U.J.Alengaram, M.Z.Jumaat and H.Mahmud ,“Influence of Cementitious Materials & Aggregates Content on Compressive Strength of Palm Kernel Shell Concrete”, Journal of applied sciences 8 (18) , Page No.:
This project reports the effect of cementitious materials, fine & coarse aggregates content on workability & compressive strength of palm kernel shell concrete. An increase in fine aggregate content & subsequent decrease in PKS content had positive effect on both workability & compressive strength. The 28 days compressive strength of mixes containing cementitious materials were found in the range of 26 to 36 Mpa.

5. Literature Survey cont……..
O.Ata, E.A.Olanipekun & K.O.Oluola, “A Comparative Study of Concrete Properties using Coconut Shell & PalmKernel Shell as Coarse Aggregates”. Build Environ.,41, Page No:
This paper presents the results of an investigation carried out on the comparative cost analysis and strength characteristics of concrete produced using crushed, granular coconut and palm kernel shells as substitutes for conventional coarse aggregate in gradation of 0%, 25%, 50%, 75% and 100%. The results of the tests showed that the compressive strength of the concrete decreased as the percentage of the shells increased. However, concrete obtained from coconut shells exhibited a higher compressive strength than palm kernel shell concrete in the two mix proportions. The results also indicated cost reduction of 30% and 42% for concrete produced from coconut shells and palm kernel shells, respectively.

6. Literature Survey cont……..
Emmanuel A.Okunade “The Effect of Wood Ash & Sawdust Admixtures on the Engineering Properties of a Burnt Laterite – Clay Brick”, Journal of applied sciences 8 (6) Page No:
The effects of the addition of sawdust & wood ash admixtures to a 70:30 parts by weight laterite-clay mix were investigated. The admixtures were added in various combinations of proportions by volume. It was discovered that the major contribution of the sawdust admixture is the reduction in the dry density of the finished burnt product. Increasing contents of sawdust in the mixes produced the opposite results in the finished products, mainly due to its effect of producing a less compact structure in the finished product.

7. Literature Survey cont……..
F.A. Olutoge,“Investigations On Sawdust And Palm Kernel Shells As Aggregate Replacement” ARPN Journal of Engineering and Applied Sciences, April Page No:7-13.
This study investigated the use of saw dust and palm kernel shells (PKS) as replacement for fine and coarse aggregates in reinforced concrete slabs. Sawdust and PKS were used to replace both fine and coarse aggregates from 0% to 100% in steps of 25%. Increase in percentage of sawdust or palm kernel shells in concrete slabs led to a corresponding reduction in both flexural and compressive strength values. It is seen that at a low replacement value of 25% sawdust and PKS can produce lightweight reinforced concrete slabs which could be used where low stress is required at reduced cost.

8. CONCRETE
Concrete is a mixture of cement, well graded fine & coarse aggregate , water.
Concrete is formed due to the reaction of cement & water. This reaction is called “hydration”.
It has high compressive strength & it is weak in tension.

9. INGREDIENTS Cement : OPC Coarse Aggregate : 12 mm size
Fine Aggregate : Sand & Sawdust
Water

10. MIX DESIGN BASED ON INDIAN STANDARD METHOD
CONCRETE MIX DESIGN
MIX DESIGN BASED ON INDIAN STANDARD METHOD
Characteristic compressive strength required in the field at 28 days – 20Mpa
Maximum size of aggregate – 12 mm
Degree of workability – 0.9 Compacting factor
Degree of quality control – good
Types of exposure – mild

11. Test Results Specific gravity of cement – 3.15
Specific gravity of coarse aggregate – 2.60
Specific gravity of fine aggregate – 2.60
Water absorption of Coarse aggregate – 0.50
Specific gravity of sawdust

12. Target Mean Strength: ft = fck + ks = 20 + (1.65 x 4) ft =26.6 Mpa
ft - target mean strength in Mpa
fck – characteristic compressive strength in Mpa
k – constant depending upon the definition of characteristic strength
s – standard deviation of the particular mix which is available in IS:

13. Water- Cement Ratio : Cement Content: Water Content:
For W/C ratio of 0.5.
Water content =197.20Kg/m3
Absolute volume of sand =40%
Water Content:
Required water content = =204 Kg/m3
water content =204 Kg/m3
Cement Content:
Volume of sand = =35.5%
Cement weight = /0.5 =406 Kg/m3
Cement weight =406 Kg/m3.

14. Volume of fine aggregate:
Volume of fine aggregate V=(w + {C/Sc} + {fa / P Sfa}) x (1/1000)
Max. size of aggregate = 12mm
Entrapped air in the wet concrete = 2.8%
0.972 = (204+ (406/3.15) + ((1/0.355) × (Fa/2.60))) (1/1000)
Fa = 596 kg/m³
Volume of coarse aggregate:
Volume of coarse aggregate CA = {(1-p)/p x (Fa x Sca)/Sfa}
Ca = (( )/0.355) ×596 × (2.6/2.6)
Ca = 1183kg/m³

15. MIX PROPORTION Water :Cement : F.A : C.A
: : : (Kg/m3)
: : : 1.183(Kg)
: : : 2.914
For 6 cubes :
Water :Cement : F.A : C.A
: : : (Kg/m3)
: : : (Kg)

16. SAWDUST Sawdust is composed of fine particles of wood.
It is a by-product of cutting lumber with a saw, hence its name.
It can present a hazard in manufacturing industries, especially in terms of its flammability.
To minimize its disposal ,it is reused such as Fuel uses, Fibre & wood base board uses, Chemical uses.

17. PROPERTIES OF SAWDUST It has low density. (about500 -1500 kg/m3)
It has better heat-and sound proofing qualities (the thermal conductivity varies from W/mK).
The modulus of elasticity is about KN/mm2
Crushing strengths of 4 -14N/mm2.
Transverse strength of N/mm2.

18. Fig. 1 SAWDUST

19. Table:1 Quantity of Concrete For Sawdust Replacement per m³%
Quantity of concrete (kg/m³)
Cement
Sawdust
sand
Coarse aggregate
406 -
596
1183 10
59.6
536.4 15
89.4
506.6 20
119.2
476.8

20. SPECIFIC GRAVITY TEST ON SAWDUST
To know the specific gravity of sawdust we can use “PYCONOMETER TEST”
G =(W2 - W1 ) / {(W4 - W1) -(W3 - W2 )}
= ( ) / {( ) - ( )} =0.45
G = Specific gravity of sawdust
W1 =Weight of dry pyconometer =0.665 Kg
W2 =Weight of sawdust + pyconometer =0.789 Kg
W3 =Weight of sawdust+ water + pyconometer =1.303 Kg
W4 =Weight of pyconometer + water =1.450 Kg

21. Fig.2. SPECIFIC GRAVITY TEST FOR SAWDUST

23. SPECIFIC GRAVITY TEST ON SAND
To know the specific gravity of sand we can use “PYCONOMETER TEST”
G =(W2 - W1 ) / {(W4 - W1) - (W3 - W2 )}
= ( ) / {( ) - ( )} = 2.6
G = Specific gravity of sand
W1 =Weight of dry pyconometer =0.665 Kg
W2 =Weight of sand + pyconometer =1.410 Kg
W3 =Weight of sand + water + pyconometer = Kg
W4 =Weight of pyconometer + water =1.450 Kg

24. Fig.4. SPECIFIC GRAVITY TEST FOR SAND

25. PREPARATION OF CUBES Cube preparation is done by 3stages Mixing
Casting
Curing

26. MIXING SAND SAWDUST FINE AGGREGATE CEMENT COARSE AGGREGATE WATER
CONCRETE

27. Table.2 Test On Concrete Cubes
% of saw dust replacement
Test cubes Compressive strength
in Tons
7 days
28 days 1 2 3
Ave. 0%
Conventional cube
16.5 16 17
17.5
18.5
17.67
10%
13.5 13 14
12.5 12
12.33
15% 11
9.8
10.5
11.83
20%
7.8
8.9
9.6
11.5
11.33

28. Fig.5.COMPARISON OF AVE.COMPRESSIVE STRENGTH OF CONCRETE AT 7 DAYS

29. Fig.6.COMPARISON OF AVE.COMPRESSIVE STRENGTH OF
CONCRETE AT 28 DAY

30. Fig.7 COMPARISON OF COMPRESSIVE STRENGTH AT 7 DAYS

31. COMPARISON OF COMPRESSIVE STRENGTH AT 7 DAYS
N/mm2
Fig.8 COMPARISON OF COMPRESSIVE STRENGTH AT 7 DAYS

32. Fig.9 COMPARISON OF COMPRESSIVE STRENGTH AT 28 DAYS
N/mm2
Fig.9 COMPARISON OF COMPRESSIVE STRENGTH AT 28 DAYS

33. Fig.10 COMPARISON OF COMPRESSIVE STRENGTH AT 28 DAYS
N/mm2
Fig.10 COMPARISON OF COMPRESSIVE STRENGTH AT 28 DAYS

34. Fig.11 CONVENTIONAL CUBE

35. Fig.12 TEST CUBE

36. Fig.13 TESTING ARRANGEMENT

37. Fig.14 FAILURE OF CONVENTIONAL CUBES

38. Fig.15 FAILURE OF TEST CUBES

39. CONCLUSION
Comparative study of concrete properties using sawdust as fine aggregate with replacement of 10%,15%,20% has been carried out.
Compressive strength of concrete is decreased with the increment of sawdust replacement.
For all percentage of sawdust replacement concrete strength is lesser than the conventional concrete in the mixer proportion of 1:1.5:3.

40. REFERENCES
U.J.Alengaram, M.Z.Jumaat and H.Mahmud (2008) ,“Influence of Cementitious Materials & Aggregates Content on Compressive Strength of Palm Kernel Shell Concrete”, Journal of applied sciences (18), Page No.:
O.Ata, E.A.Olanipekun & K.O.Oluola, “A Comparative Study of Concrete Properties using Coconut Shell & PalmKernel Shell as Coarse Aggregates”. Build Environ.,41 Page.No:
Emmanuel A.Okunade (2008) “The Effect of Wood Ash & Sawdust Admixtures on the Engineering Properties of a Burnt Laterite – Clay Brick”, Journal of applied sciences 8 (6). Page No:
F.A. Olutoge, (April 2010) “Investigations On Sawdust And Palm Kernel Shells As Aggregate Replacement” ARPN Journal of Engineering and Applied Sciences,. Page No:7-13.

41. THANK YOU