1st International Conference on Rehabilitation and Maintenance in Civil Engineering (ICRMCE)
Solo, 21-22 March 2009
ISBN No
.
THE MEASUREMENT OF WATER CONTENT USING
GYPSUM BLOCK IN GRANULER SOIL
Poernomo, Y.C.S1
Engineering Faculty Of Kadiri University, Kediri, Indonesia yos_cs@yahoo.com
Abstract
The general condition of soil water content fluctuates from saturated, unsaturated to dry. It is caused by rain, environment as well as the type of soil. This makes the soil behaving differently. This research is directed to measure soil water content using a new method. In this research, gypsum block is used to measure the soil water content in granular soil. The soil used in this research were non-organic with unsaturated condition. The gypsum blocks worked depending on the ability to absorb water that could be measured by multymeter. The gypsum blocks were in the form of cylinder blocks having 3,7 cm high, 2,1 cm in diameter. Two cable tips were inserted into the gypsum block at 1 cm spacing. The test for granular soil, was conducted on samples with volume of about 330 cm3.
Granular soil of 3% water content gave resistance 165 KΩ in gypsum block with 10% water content. The maximal result on granular soil of 20% water content had resistance of 13 KΩ in gypsum block with 61% water content. Based on these data, correlations of water
content in gypsum block and soil water content were found to be nonlinear. The correlations of the resistance of gypsum block in the granular soil w = 123,66 (R)-0,7567 with level of R2 = 0,9686.
Keyword : gypsum block, soil water content, granuler soil, unsaturated.
1. INTRODUCTION
The general condition of soil water content fluctuates from saturated, unsaturated to dry. It is caused by rain, environment as well as the type of soil. This makes the soil behaving differently. This research is directed to measure soil water content using a new method.
Unsaturated soil consisted of three shares, those are soil (solid), water (liquid) and air (gas). Civil engineering projects are often above of water level surface. There is a place of unsaturated soil.
The gypsum block are often used by a agriculture area to measuring soil moisture of the plants grow media. In this research, gypsum block is used to measure the soil water content in granular soil. The soil used in this research were nonorganic with unsaturated condition. The gypsum blocks worked depending on the
1
ability to absorb water that could be measured by multymeter. The gypsum block also can be used in environment of civil engineering.
2. BASIC THEORY
Gypsum block is used to measure the soil water content in granuler soil. The soil water content have to passing by laboratory test with sampel of soil from field and need the sufficient time. By gypsum [is] block, way of this can be [done/conducted] direct [is] field with the time which relative shorten, directly inculcate the gypsum block [of] [at] soil to be checked the
Gypsum block consisted of a solid gypsum in the form of cylinder with the determined size measure. Gypsum block equiped with two electrode in this case use the cable inculcated in gypsum block with the
1st International Conference on Rehabilitation and Maintenance in Civil Engineering (ICRMCE)
Solo, 21-22 March 2009 ISBN No
.
distance 1 cm (Scinner, 1997) in continuous current or parallel electrode at Figure 1. The Cable used as censor of absorb water into gypsum block. This matter is provable after each the cable attributed to multimeter, then will be seen the resistance of electrics current designating the existence of water content in gypsum block.
Figure 1. Cable Installation into the gypsum block
Multymeter used as resistance measured or resistance continuous current tension by pairing resistance measured in series conection with the multimeter. When the tensions source was ascertainable the late current is readable at multimeter. Equation used is :
R V
(1)
i
where :
R = resistance (Ohm )
V = electrics potential (Volt = V) i = Ampere (A)
If V expressed in volt and i expressed in ampere, hence resistance (R) will be expressed in Ohm. Current of i is equal for all wide of conductor, although at possible different dot. (Halliday And Resnik, 1978)
The gypsum block water content (w) with the ratio between weight of water content in gypsum (Ww) and weight of gypsum block in dry condition (Ws). Equation used is:
wW
w x
100 (2)
Ws
where :
w = water content in gypsum (%) Ww = berat water content in gypsum (gr) Ws = weight of gypsum block in dry condition (gr)
3 METHODOLOGY
In this research, the test of the soil water content used the gypsum block. The research facilitaties, used granuler soil with 10 % water content as reference early. It follows on that, the tested in many variation of water content. Test steps as follows as:
1. Preparing granuler soil
2. Including soil into big container with volume of about 330 cm3 at Figure 2.
7,8 cm
Figure 2. Container Test
3. The compacted [by] pursuant to and [in] deliberating
4. Including gypsum block which have [in] precise kaliberasi in the centre of the soiland [in] deliberating, visible [at] Figure 3
5. Put gypsum block into desikator
multymeter
cables gypsum block container test
Figure 3. Scheme model the especialtest
6. During shut of gypsum block measured [by] its electrics resistance with the multimeter till constant circumstance
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1st International Conference on Rehabilitation and Maintenance in Civil Engineering (ICRMCE) |
7. Corelation graph of water content between gypsum block and granuler soil.
Water content at gypsum block in granuler soil earn [is] constantly read at multymeter after keep soildiperam [of] during 2 until 3 clock. But each;everytest[of] performed within this research need the time 24 clock to ascertain the rate condition water content [at] gypsum block in a state of constant.
4. RESULT AND SOLUTION
4.1 The granuler soil properties Data which needed to this research for example result analyse the distribution of size measure item, specific gravity and assess the soil density (Tables 1)
Tables 1. The soil granuler properties
|
|
Parameter |
Result |
|
|
Specific Gravity |
3,12 |
||
|
Water content |
0,25 % |
||
|
Soil density (d) |
1,96gr/cm3 |
||
|
Fraction Gravel |
1,13 % |
||
|
Sand |
96,99 % |
||
|
Faction Silt / clay
|
1,88 %
|
4.2 Water content the gypsum block The test of water content of the gypsum block [is] inclusive of antecedent research which aim to know the variation [of] of water rate which [is] possible happened in gypsum block. This research will be conducted for 4 gypsum block (A,B,C,D) used granuler soil. Each tested, the water content 3 times and every 10 minute measured of resistance in object test such as those which seen in Figure 4.
Solo, 21-22 March 2009
ISBN No
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Figure 4. Resistance measure on gypsum block (A,B,C,D)
Base on graph of measure relation between resistance at gypsum block A,B,C,D by various of water content the ( Picture 5), [is] hence obtained [by] a[n equation that is: w =187,81(R)-0,8223 with level of R2 =0,9758
4.3 Water content of the gypsum block at granuler soil
The test of granuler soil with the water content about 3%, 5%, 10%, 15%, 20%, expected can deputize all variation of ground water rate. Data taken by goodness of soil also gypsum [is] cover the dry weight, wet weight, weight water content the, water content and volume weight. After getting result of ratio [of] [among/between] water content [at] granuler soil with the water content in gypsum block in 5 times test to 4 sampel of granuler soil with the variation [of] of rate airnya, [is] hence obtained [by] result of rate test water content [at] granuler soil with the resistance that happened [at] gypsum block
Result of rate test water content [at] this soil granuler, [is] hereinafter ploted [at] graph of rate ratio water content [at] gypsum block and granuler soil (Figure 5) and found to be linear result as follows.
Figure 5. Ratio of water content at gypsum block and granuler soil.
Resistance that happened at 4 sampel of granuler soil ploted connective graph between resistance of gypsum block with the granuler soil in so many variation of water content (Figure 6).
1st International Conference on Rehabilitation and Maintenance in Civil Engineering (ICRMCE)
Solo, 21-22 March 2009 ISBN No
.
Figure 6. Resistance measure result of gypsum
block at granuler soil
Based on these graph, correlations of water content in gypsum block and soil water content were found to be nonlinear. The correlations of the resistance of gypsum block in the granular soil w = 123,66 (R)-
0,7567 2 with level of R = 0,9686.
5. CONCLUSIONS
The gypsum block applicable to measure soil water content in granuler soil with unsaturated condition which must laboratory calibration first.
The gypsum blocks were in the form of cylinder blocks having 3,7 cm high, 2,1 cm in diameter.
Granular soil of 3% water content gave resistance 165 KΩ in gypsum block with 10% water content. The maximal result on granular soil of 20% water content had resistance of 13 KΩ in gypsum block with 61% water content.
Based on these data, correlations of water content in gypsum block and soil water content were found to be nonlinear.
The correlations of the resistance of gypsum block in the granular soil w = 123,66 (R)-
0,7567 2 with level of R = 0,9686.
ACKNOWLEDGEMENT
The authors wish to thanks Christady, H.C. and Rifa’i, A. for the support given through out this research.
REFERENCES
1. ASTM, 2003, Annual Book of ASTM standards Section 4 Volume 04.08 Soil and Rock (I): D 420 – D 5611
2. Campbell, J.M. and Clause, 1998, Using Gypsum Block For Measure Soil Moisture In Vineyards,Viticulture reseach Office,West Australia, pp. 1-9
3. Combe, E.C., 1992, Notes On Dental Materials, Sixth Edition, Longman Group UK, New York, pp. 187-191
4. Dela, B.F., 2001, Measurement Of Soil Moisture Using Gypsum Block, Danish Building and Urban Research 004, Hersholm, pp. 8-17
5. Fredlund, D.G. and Rahardjo, H., 1993, Soil Mechanics for Unsaturated Soils, John Wiley and Sons, Inc., New York, pp. 21-22
6. Goodwin, I., 2000, Gypsum Block for Measuring The Dryness of Soil,
AG0294, States of Victoria, pp. 1-3
7. Hardiyatmo, H.C., 2002, Teknik Fondasi I, Second Edition, Beta Offset, Yogyakarta, pp. 1-13
8. Hardiyatmo, H.C., 2002, Mekanika Tanah I, 3th edition, Gadjah Mada University Press, Yogyakarta, pp. 1-19
9. Halliday, D. and Resnik, R., 1978, Physics, John Wiley and Sons,
Pittsburgh, pp. 182-196
10. Poernomo, Y.C.S., 2008, Pengukuran Kadar Air Tanah Menggunakan Gypsum Block, M.Eng. Thesis, Gadjah Mada University, Yogyakarta.
11. Skinner, A., Hignett, C. and Dearden, J.,(1997), Resurrecting The Gypsum Block for Soil Moisture Measurement, Magill, South Australia, pp. 1-8.
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