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Producing Paving Block by Using Sawdust as the Main Materials
to Substitute Sand
Novian Mahardika Putra
SMA Sugar Group
To fulfill requirement of life which progressively increases, we need to conduct new invention which is more useful for life. Therefore “Make paving block with elementary materials from sawdust to substitute sand" was conducted to find the new thing which is useful for society, because this paving block is easy to be made. Also considering from the estimated cost paving block from sawdust is cheaper than paving block made of sand because the price of sawdust is cheaper. The changes of the main material caused the quantity of sand which is estimated will be decrease in certain range of time.
This research has been done in Housing 2 PT GPM on 24 until 30 March 2008.This research had 4 methods. The first method was to gather information about paving block. The second method was to collect all materials. The third method was to do the experiment, then calculation. The last method was to test the paving block made of sawdust. To testing the strength of paving block, 5 series of tests were conducted, namely; that were structure test, form test, fall test, scratch test and weight test.
The result of this research indicated that paving block made of sawdust had strength which was almost equal with the paving block made of sand. If the process of paving block making is precise, the strength of sawdust paving block will be equal with sand paving block.
Keyword: Paving Block, Sawdust, Sand Resource, Cement, Curing Process.
We know that around us there are many kinds of waste materials as result of our daily activity. One of the waste materials is sawdust. Sawdust is tiny pieces of wood. In making furniture, it usually can we used as the materials. Any kinds of wood can be used to produce sawdust. If compacted, it will have a solid form that sustains heavier objects.
Sawdust can be told waste if produced continually without processing it can cause air pollution. The effect of it is a problem in respiratory system. In a fact sawdust could be exploited as media cultivation of mushroom and the material of furniture.
Background of this research is because the available of sawdust waste that need to be used with other way beside use it to make furniture or as media cultivation of mushroom. The aim of this research is to make economic paving block with good quality which is not use sand because sand estimated its amount will decrease in certain range of time and also to help building coolie with produce light paving block. Problem of the research was “was paving block from sawdust as strong as sand paving block?” the limitation of this research problem was to test the strength between sand paving block and sawdust paving block in GPM housing scale.
Review of Literature
This research was also supported by research that had been conducted by Dr.Ir.Bambang Subiyanto about sand resources that had been decrease. This is statement from Dr.Ir.Bambang Subiyanto.
The available of sand surely will be decrease, then price of sand will be expensive and purchase power of society will be decrease. Also because some provinces in Indonesia have limited potential of sand, but have many potential of wood. For example is Kalimantan Island. (Dr.Ir. Bambang Subiyanto).
Materials and Methods:
The materials and tools that was used in this research are 13, 5 kg of sawdust, 39 kg of cement, sufficiently water, 0.10 Liters used oil, medium size pail, paving block mould, Cement spoon.
Location and time:
The research was conducted in Housing 2 PT.GPM on 24 until 30 March 2008. This research had 3 steps they were: gathering and selection the materials, mixing all materials until they become paste, mould the paving block and do curing process / draining process by placing it without being exposed to the sunlight.
1. Paving block mould was made with the size of: length; 23 cm, width; 11 cm, height: 6 cm. See picture 1.
Picture 1. Mould of paving block
2. The sawdust was prepared by cleaning it from foreign object within, if it is wet, it must dried first.
3. Before the cement would be mixed with sawdust, make sure it can be used. If the cement was lump, it cannot be used.
4. All materials were placed into the pail with comparison 1: 2, mixed and added water sufficiently. Kept stirring until it became a paste as shown on picture 2 and 3.
Picture 2. One cement spoon.
Picture 3. Paste.
5. Before paste was put into the mould better to give the oil on its walls.
6. The paste was put into mould. After 10 minutes then the mould was removed and let paving block was dried with process of curing. It took around 7 day. See picture 4.
Picture 4. Curing Process
This research used 4 methods to make paving block and to prove sawdust paving block was strong and could be used. The methods were:
1. Finding information about paving block.
2. Collecting the materials.
3. Experimenting and calculating.
4. Testing the paving block.
Kinds of Paving block tests:
1. Structure test of Paving block
The good structure of paving block is without any hole, gap and crack.
2. Form & size test
The good paving block has an even square.
3. Fall test
Paving block with endurance will not be broken when dropped from 1 meter height. See Picture
Picture 6. Fall Test.
4. Test scratch
The surface of good paving block will not be affected when one of its sides is scratched. It happens when the curing process is accurately done.
5. Weight test
Light paving block would benefit in terms of road construction, if it would complete faster. This test was used to find out whether or not sawdust paving block was lighter or heavier than sand block paving.
Result and Discussion
Table 1. Tests Result.
Name of testes
Condition of paving block
The process off mould was not accurate
Paving Block from Sawdust
Paving Block from sand
To Produces 46 paving with size 23 x 11 x 6 need cost:
a) Cement 40 kg Rp. 44.000,-
b) 0, 25 m³ of sand Rp. 18.750,-
c) 0.10 liter of oil Rp. 2300,-
Cost for 1 Paving block Rp. 1.414,-
Cost for 1 m3 paving block (25) Rp. 35.353,-
To produces 46 paving block from sawdust with size 23 x 11 x 6 need cost:
a) Cement 39 kg Rp. 42.900,-
b) 13.5 kg of sawdust Rp. 13.500,-
c) 0.10 liter of oil Rp. 2300,-
Cost for 1 paving block Rp. 1.276,-
Cost for 1 m3 paving block (25) Rp. 31.902,-
· The price of cement, oil, water and sand in every area were different. But the price that was used referring the price in PT GPM.
· Water did not have price because that was PT GPM scale and in GPM water was free.
· The result in scratch test was sufficient because process of curing need more time.
· The result in structure test was sufficient because the process off mould was not accurate.
· The result from weight test is the sawdust paving block is lighter than sand paving block and that will be give big advantage if produce in big amount.
Conclusion and Suggestion
Sawdust could be used as the main material of paving block substituting sand, based on tests, it could be concluded that the strength of sawdust paving block is equal to sand paving block. Providing the process of mould the paving block was accurate.
Any parties that want to continue this research are expected to be more careful in mould and measuring processes. It is better to use good mould and use time effectively.
Thanks to Mr. Joko as supervisor and Mr. Bagio as examiner who has given support and has helped to finish this research.
Muller Claudia, et. al. .2006. Modul pelatihan pembuatan ubin atau paving blok dan batako. http://www.ilo.org/public/indonesia/region/asro/jakarta/download/manualblok.pdf. Access on 4th March 2008.
Subiyanto Bambang, http://www.inovasi.lipi.go.id. Access on 4th March 2008.