UTILIZATION OF FLY ASH AS MATERIAL MIXED SOIL LAYER BASICS IN HIGHWAY CONSTRUCTION

CERUCUK Volume 1 No. 2 2017 (67-76)

UTILIZATION OF FLY ASH AS MATERIAL MIXED SOIL LAYER BASICS IN HIGHWAY CONSTRUCTION Rina Aulia Purnamasari and Yasruddin Civil Engineering Department, Lambung Mangkurat University E-mail : [email protected]

ABSTRAK Penggunaan bahan bakar batu bara pada pembangkit listrik dan industri termasuk pada unit Asphalt Mixing Plant (AMP) menyisakan limbah abu batu bara yang banyak dan menjadi masalah bagi lingkungan. Pemanfaatan limbah batu bara dilakukan dalam berbagai macam keperluan termasuk untuk konstruksi yaitu sebagai bahan campuran lapisan tanah dasar pada konstruksi jalan raya. Tujuan dari penelitian ini untuk mengetahui nilai karakteristik dari masingmasing kombinasi tanah, semen, dan fly ash sebagai bahan campuran lapisan tanah dasar dengan komposisi campuran 1 fly ash 25%, semen 15%, tanah 60%, campuran 2 fly ash 30%, semen 10%, tanah 60%, dan campuran 3 fly ash 35%, semen 5%, tanah 60%. Adapun pengujian yang dilakukan yaitu pengujian atterberg limit, spesific gravity, hidrometer, analisa saringan, kompaksi dan CBR. Dari hasil penelitian ketiga variasi campuran didapat nilai CBR yang paling tinggi pada kombinasi fly Ash 1 yaitu 54% yang melebihi nilai spesifikasi umum yaitu minimum 6% sebagai bahan timbunan biasa, akan tetapi nilai aktif yang didapat dari ketiga benda uji, tidak ada satu pun yang memenuhi standar spesifikasi yaitu <1.25. Sehingga kombinasi dari fly ash 1, 2, dan 3 dapat digunakan sebagai bahan timbunan biasa dengan persayaratan bahan digunakan hanya pada bagian dasar dari timbunan atau pada penimbunan kembali yang tidak memerlukan daya dukung atau kekuatan geser yang tinggi, selain itu bahan tersebut hanya boleh digunakan diatas 30 cm dari muka air tanah atau lapisan langsung di bawah bagian dasar perkerasan atau bahu jalan atau tanah dasar bahu jalan. Kata kunci : Fly Ash, Karakteristik Tanah Dasar, Spesifikasi Bina Marga. ABSTRACT The use of coal-fired electricity generation and industries including the unit Asphalt Mixing Plant (AMP) coal ash waste leaving the lot and become a problem for the environment. Utilization of coal waste is done in a variety of purposes including for construction, namely a mixture of base soil layer in road construction. The purpose of this study to determine the value of the characteristics of each combination of soil, cement and fly ash as a mixture of soil layer base with the composition of the mixture of 1 fly ash 25%, cement 15%, soil 60%, a mixture of 2 fly ash 30%, cement 10%, 60% land, and the mixture 3 35% fly ash, cement 5%, 60% land. The testing is done is test Atterberg limits, the specific gravity hydrometer, sieving, compacting and CBR.

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CERUCUK,Volume 1 No. 2 2017

From the results of the third study variations in the mixture obtained value of the CBR highest in the combination of fly Ash 1 was 54%, which exceeds the value of the common specifications are a minimum of 6% as a heap of unusual, but the value of active obtained from the three test objects, none of which meet the specification of <1:25. So the combination of fly ash 1, 2, and 3 can be used as embankment usual with the terms of materials used only on the bottom of the heap or on the backfilling that does not require carrying capacity or strength of the shear is high, besides the material can only be used above 30 cm from the ground water level or the layer directly below the bottom of the pavement or road shoulder or shoulder of the road subgrade. Keywords: Fly Ash, Soil Characteristics Basic Specifications of Highways. 1. INTRODUCTION The use of coal-fired electricity generation and industries including the unit Asphalt Mixing Plant (AMP) coal ash leaves very much and become a problem for the environment. Efforts to use waste has been carried out for a variety of purposes including for construction. So far the research on the utilization of waste fly ash have been carried out such as “Pengaruh Pemanfaatan Abu Terbang (Fly Ash) Dalam Beton Mutu Tinggi” (Mardiono, 2016), “Studi Penambahan Abu Batubara Sebagai Filler Pada Campuran Beraspal” (Syaiful dan Setiana Mulyawan, 2016), and “Kajian Teknis Dan Ekonomis Pemanfaatan Limbah Batu Bara (Fly Ash) Pada Produksi Paving Block” (Endah Safitri dan Djumari, 2009). However, the use of fly ash in the field of highway construction is still under-developed and must be optimized in order to help the government

overcome

the

effects

of

environmental

pollution.

Based on the description above, the writer tried to do research on "Use of Fly Ash as Material Mixed Soil Layer Basics In Highway Construction". In this study the authors working with the power plant so that the levels acids a mixture of cement, fly ash, and the land acquired has been determined. 2. THEORITICAL STUDY Basic ground is the basic part of the road that lies on the bottom layer of the road pavement. The strength and durability of the pavement is highly dependent on the properties and the carrying capacity of the subgrade. Therefore, the planning of new roads should be held thorough examination of soil in places that will be used as the basis of land that serves to support the street paving. Based on the Indonesian National Standard (SNI) No. 15-2049-2004, hydrolysis cement Portland cement is produced by grinding the slag (Clinker) portland mainly

Utilization Of Fly Ash … Rina Aulia

69

composed of calcium silicate (xCaO.SiO2) which is hydraulically and ground together with the ingredients additional form of one or more crystalline forms of the compound calcium sulfate (CaSO4.xH2O) and may be combined with other additives (Mineral-in component). The main chemical constituent of cement is calcium silicate (xCaO.SiO2), calcium sulphate (CaSO4.xH2O) and other additives (Mineral-in component) which will act as a cement filler. Where the minerals calcium silicate (xCaO.SiO2) are particularly hydraulic, in the cement industry cement constituent minerals termed as C3S, C2S, C3A and C4AF meaning, C3S = 3CaO.SiO2, C2S = 2CaO.SiO2, C3A = 3CaO.Al2O3, C4AF = 4CaO.Al2O3.Fe2O3. ly ash is a coal industrial waste produced from burning coal and consists of fine particles. Fly ash discharged from the combustion chamber through the boiler in the form of bursts of smoke, which has been used as an ingredient in concrete. According to ACI 226 Committee explained that, fly-ash has pretty fine granules, which passes a sieve N0. 325 (45 milli micron) 5-27%, with the specific gravity of between 2.15 to 2.8 and blackish-gray color. The nature of the process of fly-ash pozzolanic similar to other pozzolan materials. According to ASTM C.618 (ASTM, 1995: 304) of fly ash is defined as fine grains of coal combustion residues or powdered coal. The main component of Yag coal fly ash from power plants is a silicate (SiO2), alumina (Al2O3), and iron oxide (Fe2O3), the rest is carbon, calcium, magnesium, and sulfur. The chemical properties of coal fly ash is affected by the type of coal burned and the storage and handling techniques. Atterberg Limit Test is a test method to determine the consistency of properties of fine-grained soil (silt or clay) to provide a different water content in each sample to be tested. Soil properties can be determined by comparing the water content contained in each soil sample. In 1913 Albert Mauritz Atterberg limits stated four ground conditions in terms of "limit", namely: 1. Shrinkage Limit which is the boundary between the semi-solid and solid. 2. Plastic Limit which is the boundary between the plastic and semi-solid. 3. Liquid Limit which is the boundary between the liquid and plastic. Atterberg Limits purpose is to know the limitations of the four conditions of land owned by a soil sample to be tested.

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For basic soil layer on the usual pile soil excludes the high berplastisitas, which are classified as A-7-6, according to SNI 03-6797-2002 (AASHTO M145) or as CH by "or Cassagrande Unified Soil Classification System". To pile on soft ground grained selection marshland or plasticity index should have a maximum of 6%. The purpose of Spesific Gravity SNI 1961:2008 test to obtain the number of bulk density, dry density, surface pseudo type and weight and the amount of absorption figures. Land used in the specific gravity test done to test object wet or dry test specimen oven. The weight of the oven dried sample of at least 25 grams using a measuring bottle, and at least 10 grams when using a bottle equipped with a lid. This examination is intended to determine the gradation / distribution of grains of coarse aggregate and fine aggregate by using a sieve SNI 03-1968-1990. Aggregate is the grain size distribution of aggregates. This experiment was conducted to determine the properties of the physical, mechanical, and aggregate technology and its influence on road pavement materials properly. Hydrometer SNI 3423:2008 is an instrument used to measure the specific gravity (or relative density) of a liquid, the liquid density ratio with the density of water. Hydrometer testing required for the test object through sieve no. 200 as much as 50 ounces with a mixed composition Tamp soil compaction SNI 1742:2008 is the process by removing the air from the pores of the soil by mechanical means (beaten, crushed, and so on). Compaction or Kompkasi carried out with the aim to improve the engineering properties of soil which derive most solid ground state (solid state maximum). California Bearing Ratio (CBR) SNI 1744:2012 is the ratio between load penetration of a substance to the standard material in the depth and penetration of the same speed. Soil strength tested by the CBR test according to ISO-1744-1989. The soil strength value is used as a reference to whether or not stabilized as compared with the requirements in the specifications. For basic soil layer on the usual pile CBR value of not less than 6% after 4 days of immersion when compacted 100% maximum dry density (MDD) as defined by SNI 03-1742-1989). For CBR heap of options have at least 10% after 4 days of immersion when compacted to 100% maximum dry density in accordance with ISO 1742: 2008. CBR value is calculated on the penetration of 0.1-inch


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and 0.2-inch penetration and further results of the two calculations are compared in accordance with SNI 03-1744-1989 taken the greatest results. Table 1. The composition of the mixture and Total Sample No

Composition

Amount

Fly Ash

Cement

Soil

1

25%

15%

60%

1

2

30%

10%

60%

1

3

35%

5%

60%

1

Total Sample

3

3. RESULT AND DISCUSSION The importance of the value of liquid limit of 36.60%, and for the calculation of the value of plastic limit can be found in appendix D, plastic limit value obtained is 20:47%. In order to get the value of PI of 16:13%. The obtained value of the liquid limit for combination 1 49.05% 47.25% 2 combinations, and the combination of 3 49.05%. Value of a combination of plastic limit 1 25.66% 27.17% 2 combinations, and the combination of 3 29.67%. Then the PI values obtained from the three combinations, namely, a combination of 1% 23:39, 20:08 the combination of 2%, and the combination of 3 19:38%. PI value obtained from the calculation of liquid limit minus the plastic limit. For the calculation of the specific gravity of the soil testing is 2.68. Value GS combination of fly ash, cement and soil, namely, a combination of 1 2.95, combination 2 is 2.89, and the combination of 3 2.83. On testing hydrometer active value can be known from the value of PI divided by levels of clays. The current values of land is the land value changes in volume caused by moisture. The current values obtained in soil testing is 1:15, while active value obtained on a combination of fly ash, cement, soil is the first combination of 1.89, a combination of 2 is 1.69, and the combination of 3 1.68. Then the GI values obtained for subgrade soil is 3 classes were. For the classification of the three combinations based on AASHTO then to a combination of 1, 2, and 3, including as A-2-7, and the GI value for the first 4 class combination subgrade

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medium, a combination of both 3 classes subgrade medium, and the third a combination of two classes subgrade was. From the results of sieve analysis test and classification under the system USCS then obtained: Table 2. Sieve Analysis Test And Classification Under The System USCS No. Classification

Soil

Combination Combination Combination 1

2

3

1

Gravel (> 0.45 mm)

27.76%

28.68%

29.09%

29.34%

2

Sand (0.45 to 0.075 mm)

28.65%

32.21%

33.34%

34.18%

3

Silt (<0.075 mm)

4.94%

5.79%

4.78%

3.91%

4

Clay (0.001 to 0.005 mm)

38.65%

33.32%

32.79%

32.57%

The calculation result compacting soil test results obtained value of DDM 1.876gr / cm3 and OMC value of 10.60%. The first combination DDM 1.8gr / cm3, OMC 15:00%, a combination of both DDM 1.81gr / cm3, OMC 17:50%, and for the third combination DDM value of 1.85 g / cm3, OMC 11:50%. From the results of calculations for the land acquired DDM value of 10.4%, and in 95% of DDM at 7:00%. As for the first combination DDM value obtained for 54.00%, on a 95% DDM 50%, the combination of the value of DDM 12:00%, at 95% DDM 10%, and for the third combined value of DDM 9:50%, at 95% DDM 6.90%. Table 3. Soil Characteristics Value


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Table 4. Characteristics Value Combination Fly Ash, Cement and Soil

Atterbeg testing limits in soil plasticity index values obtained 16:13%, and for the combination of fly ash 1, 2, and 3 obtained value for the index plastically 23:39%,

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20:08% and 19:38%. Which is based on the general specifications bina clan for ordinary pile material selected should include land that is not high berplastisitas, which are classified as A-7-6, according to SNI-03-6797-2002 (AASHTO M145) or as CH according to the "Unified or Casagrande Soil Classification System ", but this material can still be used as timbunana usual with the requirements of such materials should be used only on the bottom of the heap or the backfilling that do not require the carrying capacity or strength of the shear is high, besides the material can only be used above 30 cm from the ground water level or the layer directly below the bottom of the pavement or road shoulder or shoulder of the road subgrade. Whereas, for a heap of options, this material does not meet the general specifications that require materials with plasticity index value of a maximum of 6%. To test the specific gravity of the soil value obtained at 2.68, on a mixture of fly ash 1, 2, 3, the value obtained is 2.95, 2.89, and 2.83. The value of the test results and sieving the specific gravity is only used to complete the calculation of the hydrometer testing to get active value which is required on the common specifications for the clan bina regular heap. The current values of the test results of soil hydrometer for 1:15, while the fly ash from the combination of 1, 2, 3, obtained value of 1.89, 169, 168. Based on the general specifications of the active value for ordinary pile is <1.25, and the results of the tests found that the soil can used as an ordinary pile, while the combination of fly ash 1, 2, 3, active value obtained is big enough and does not meet specifications to be used as an ordinary pile. For the test of compaction on soil obtained value of the dry density of maximum 1,876 and optimum moisture content 10.6%, for the combination of fly ash 1, 2, 3, the value of dry density maximum of 1.8, 1.81, 1.85 and optimum moisture content 15:00%, 17:50%, 11:50%. The optimum moisture content in the compaction test is used for testing the CBR, the CBR testing ground where the obtained value of the CBR at 10.4% of maximum dry density and CBR at 95% maximum dry density 7:00%. While fly ash from a combination of 1, 2, 3, obtained CBR value at 54.00% maximum dry density, 12:00% 9.50% and the CBR at 95% maximum dry density 50.00%, 10:00%, 6.90%. According to specifications common to pile the ordinary must have a CBR value of not less than 6% and for a heap of options must have the CBR at least 10%, so that the results of soil testing and the combination of fly ash 1, 2, CBR value obtained meet


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the specifications to be used as ordinary pile or heap of options, while the combination of fly ash 3 can only be used as a regular heap. So of all the results of testing that has been done, the land meets the specifications for use as an ordinary pile. After combination with fly ash and cement, fly ash both on a combination of 1, 2 and 3, the value of active and PI values obtained larger than the specification, so that the material can still be used as an ordinary pile with certain requirements. In addition CBR value obtained after the combination is quite larger than the CBR value of the land itself. 5. CONCLUSION 1. The combination of fly ash 1 with a composition of 25% fly ash, cement 15%, soil 60%, resulting in a value of 23:39% plasticity index, the active value is 1.89, CBR 54%, fly Ash 2 with a composition of 30% fly ash, cement 10% , soil 60%, resulting in a value of plasticity index of 20:08%, a value of on 1.69, CBR 12% and fly Ash 3 with the composition of the fly ash 35%, cement 5%, soil 60%, resulting in a value of plasticity index of 19:38%, a value of on 1.85, CBR 9.5%. Then the third such combination meets the characteristic values enough to be used as a mixture of basic soil layer with the usual pile classification on highway construction. 2. The right combination of a mixture of fly ash, cement and soil that can be used as a base layer of soil on highway construction, namely the combination 1 25% fly ash, cement 15%, and 60% soil, the CBR value gained 54%.

REFERENCES Badan Standarisasi Nasional, 1989. SNI.03-1744-1989: Metode Pengujian CBR Laboratorium. Badan Standarisasi Nasional, 1990. SNI.03-1968-1990: Metode Pengujian Analisa Saringan Agregat Halus dan Kasar. Badan Standarisasi Nasional, 1990. SNI. 03-1996-1990: Metode Pengujian Batas Plastis Tanah. Badan Standarisasi Nasional, 1992. SNI. 03-2832-1992: Metode Pengujian Untuk Mendapatkan Tanah Maksimum dengan Kadar Air Optimum. Badan Standarisasi Nasional, 2008. SNI. 1961:2008: Cara Uji berat Jenis tanah.

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Badan Standarisasi Nasional, 2008. SNI.1967:2008: Cara Uji Penentuan Batas Cair Tanah. Badan Standarisasi Nasional, 2008. SNI. 1969:2008: Cara Uji Berat Jenis dan Penyerapan Air Agregat Kasar (Specific Gravity). Badan Standarisasi Nasional, 2008. SNI. 3423:2008: Cara Uji Analisis Ukuran butir tanah. Badan Standarisasi Nasional, 2012. SNI. 1744:2012: Metode Uji CBR Laboratorium. Departemen Pekerjaan Umum, 2006. Pedoman Penyelidikan dan Pengujian Tanah Dasar Untuk Perkerasan Jalan Buku 3. Direktorat Jenderal Bina Marga, Jakarta. Departemen Pekerjaan Umum, 2006. Pekerjaan Tanah Dasar Buku 1 Umum. Direktorat Jenderal Bina Marga, Jakarta. Departemen Pekerjaan Umum, 2006. Pekerjaan Lapis Pondasi Jalan Buku 1 Umum. Direktorat Jenderal Bina Marga, Jakarta. Kementrian Pekerjaan Umum, 2010. Spesifikasi Umum 2010 Revisi 3 Divisi 3 Pekerjaan Tanah. Jakarta. Direktorat Jendral Bina Marga. Mardiono. 2016. “Pengaruh Pemanfaatan Abu Terbang (Fly Ash) Dalam Beton Mutu Tinggi”. Jurnal Teknik Sipil Fakultas Teknik Sipil Dan Perencanaan Universitas Gunadarma. Jakarta. Safitri Endah, dan Djumari. 2009. “Kajian Teknis Dan Ekonomis Pemanfaatan Limbah Batu Bara (Fly Ash) Pada Produks Paving Block”. Media Teknik Sipil. Vol IX. Sukirman Silvia. 2010. “Perencanaan Tebal Struktur Perkerasan Lentur”. Nova. Bandung. Syaiful, dan Setiana Mulyawan. 2015. “ Studi Penambahan Abu Batubara Sebagai Filler Pada Campuran Bersapal”. Jurnal Teknik Sipil Fakultas Teknik Universitas Ibn Khaldun. Bogor. Universitas Lambung Mangkurat, 2010. Pedoman Penulisan Karya Ilmiah. Program Studi S1 Teknik Sipil. Banjarbaru. Yudhistira, 2014. Laporan Praktikum Mekanika Tanah Dasar. www.academia.edu. Diakses pada Tanggal 10 Februari 2016.

UTILIZATION OF FLY ASH AS MATERIAL MIXED SOIL LAYER BASICS IN HIGHWAY CONSTRUCTION

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