PENGARUH GRADASI TERHADAP NILAI CBR MATERIAL CRUSHED LIMESTONE Ilman Isramdhani Rahman NRP: 1421904 Pembimbing: Andrias Suhendra Nugraha, S.T., M.T. ABSTRAK Lonjakan pertumbuhan lalu lintas pada suatu daerah yang melebihi kriteria desain pada suatu konstruksi jalan akan memperpendek umur rencana dari perkerasan jalan. Keadaan ini berdampak pada kenaikan biaya perawatan jalan yang dikeluarkan. Salah satu cara untuk menurunkan biaya tersebut maka diupayakan adanya efesiensi dan quality control dari berbagai komponen pembangunan konstruksi jalan. Salah satu komponen quality control tersebut adalah tinjauan terhadap kualitas material yang akan digunakan sebagai material pada subgrade, subbase, dan base dari suatu desain perkerasan jalan. Penelitian ini bertujuan untuk mengkaji pengaruh gradasi material crushed limestone terhadap nilai CBR (California Bearing Ratio). Material limestone yang digunakan pada penelitian ini berasal dari dua daerah yaitu; Padalarang dan Sukabumi, Jawa Barat. Jenis Gradasi yang akan dikaji adalah poorly graded/gradasi buruk (material Padalarang, dmax = 4,75mm) dan well graded/gradasi baik (material Sukabumi, dmax = 4,75mm). Metode uji CBR yang dilakukan adalah uji CBR laboratorium yang mengacu pada standar ASTM D-1883-99. Pengujian CBR laboratorium untuk material crushed limestone poorly graded menggunakan metode variasi kadar air, w (range of water content), sementara untuk material crushed limestone well graded dilakukan hanya dalam kondisi kadar air, w = 0,1%. Untuk kedua jenis gradasi, jumlah tumbukan perlapis (blows per layer) yang digunakan adalah 25 blows per layer dan 56 blows per layer. Hasil penelitian untuk material crushed limestone poorly graded diperoleh nilai CBR tertinggi = 26,25%, pada kondisi; energi kompaksi 56 blows perlayer, kadar air, w = 0,088% dan nilai dry density, dry = 1,594gr/cm 3, sementara untuk material crushed limestone well graded diperoleh nilai CBR tertinggi = 27,54%, pada kondisi; energi kompaksi 56 blows perlayer, kadar air, w = 0,11% dan nilai dry density, dry = 1,768gr/cm 3. Pengaruh perubahan kondisi gradasi material crushed limestone dari poorly graded ke well graded dengan energi kompaksi 56 blows per layer hanya mengalami kenaikan nilai CBR sebesar 4,9%. Klasifikasi lapisan konstruksi jalan berdasarkan kurva stress-penetration (Porter. O.J., 1942) untuk material crushed limestone baik pada gradasi material poorly graded dan well graded, termasuk kedalam klasifikasi good subgrade. Kata Kunci: Crushed Limestone, CBR, Poorly Graded, Well Graded. ix
GRADATION EFFECT FOR CBR VALUE OF MATERIAL CRUSHED LIMESTONE Ilman Isramdhani Rahman NRP: 1421904 Supervisor: Andrias Suhendra Nugraha, S.T., M.T. ABSTRACT The surge in traffic growth in an area that exceeds the design criteria on a road construction would shorten the design life of the pavement. This situation resulted in increased road maintenance costs incurred. One way to reduce these costs then attempted control their efficiency and quality of the various components of road construction. One component of the quality control is a review of the quality of the materials to be used as the material on the subgrade, subbase and base of a road pavement design. This study aimed to assess the effect of graded crushed limestone material to the value of CBR (California Bearing Ratio). Limestone material used in this study came from two areas, namely; Padalarang and Sukabumi, West Java. Gradient type that will be studied is poorly graded (Padalarang material, dmax = 4,75mm) and well graded (material Sukabumi, dmax = 4,75mm). The test method conducted CBR CBR is testing laboratory which refers to the standard ASTM D-1883-99. CBR testing laboratory for material crushed limestone poorly graded using the method of variation of moisture content, w (range of water content), while for the material well graded crushed limestone done only under conditions of water content, w = 0,1%. For both types of gradation, the number of collisions (blows per layer) used is 25 blows per layer and 56 blows per layer. Results of research for the material poorly graded crushed limestone obtained the highest CBR value = 26,25%, on the condition; 56 blows perlayer energy compaction, moisture content, w = 0,088% and a dry density value, dry = 1,594gr/cm 3, while the material is well graded crushed limestone obtained the highest CBR value = 27,54%, on the condition; 56 blows perlayer energy compaction, moisture content, w = 0,11% and a dry density value, dry = 1,768gr/cm 3. Effect of changes in material conditions gradation of poorly graded crushed limestone to well graded with energy compaction 56 blows per layer only increased the CBR value of 4,9%. Classification of road construction layers based stress-penetration curve (Porter. O.J., 1942) for both the material crushed limestone material gradation poorly graded and well graded, including classification into good subgrade. Keywords: Crushed Limestone, CBR, Poorly Graded, Well Graded. x
DAFTAR ISI HALAMAN JUDUL... i LEMBAR PENGESAHAN... ii PERNYATAAN ORISINALITAS LAPORAN PENELITIAN... iii PERNYATAAN PUBLIKASI LAPORAN PENELITIAN... iv SURAT KETERANGAN TUGAS AKHIR... v SURAT KETERANGAN SELESAI TUGAS AKHIR... vi KATA PENGANTAR... vii ABSTRAK... ix ABSTRACT... x DAFTAR ISI... xi DAFTAR GAMBAR... xiii DAFTAR TABEL... xv DAFTAR NOTASI... xvi DAFTAR LAMPIRAN... xvii BAB I PENDAHULUAN... 1 1.1 Latar Belakang... 1 1.2 Tujuan Penelitian... 2 1.3 Ruang Lingkup Penelitian... 2 1.4 Sistematika Penulisan... 2 BAB II TINJAUAN LITERATUR... 3 2.1 Limestone... 3 2.2 Manfaat Limestone... 3 2.3 Karakterisasi Material... 5 2.3.1 Plate Loading Test... 5 2.3.2 Uji CBR (California Bearing Ratio)... 6 2.3.2.1 Manfaat dan Kegunaan... 6 2.3.2.2 Rangkuman Metode Pengujian... 7 2.3.2.3 Perhitungan CBR... 7 2.3.2.4 Pengujian CBR... 10 BAB III METODE PENELITIAN... 12 3.1 Diagram Alir Penelitian... 12 3.2 Persiapan Alat Dan Bahan... 14 3.3 Pengujian CBR Laboratorium Material Crushed Limestone... 19 3.3.1 Proses Persiapan Sampel Uji Material Crushed Limestone... 20 3.3.2 Proses Uji Kompaksi/Pemadatan Untuk Sampel Pada Pengujian CBR Laboratorium Material Crushed Limestone... 21 3.3.3 Uji CBR Laboratorium Material Crushed Limestone... 22 BAB IV ANALISIS DATA... 24 4.1 Sieve Analysis (Analisis Ayak)... 24 4.2 Hasil Uji Indeks Properti Material Crushed Limestone... 27 4.2.1 Specific Gravity (Gs)... 27 4.2.2 Water Content (w)... 28 xi
4.3 Pengujian CBR Laboratorium Material Crushed Limestone Padalarang... 29 4.3.1 Hasil Uji CBR Laboratorium Sampel Uji SU1wi (56)... 30 4.3.2 Hasil Uji CBR Laboratorium Sampel Uji SU2wi (56)... 31 4.3.3 Hasil Uji CBR Laboratorium Sampel Uji SU1wi (25)... 32 4.3.4 Hasil Uji CBR Laboratorium Sampel Uji SU2wi (25)... 33 4.3.5 Hasil Uji CBR Laboratorium Sampel Uji SU1w1 (56)... 34 4.3.6 Hasil Uji CBR Laboratorium Sampel Uji SU2w1 (56)... 34 4.3.7 Hasil Uji CBR Laboratorium Sampel Uji SU1w1 (25)... 35 4.3.8 Hasil Uji CBR Laboratorium Sampel Uji SU2w1 (25)... 36 4.3.9 Hasil Uji CBR Laboratorium Sampel Uji SU1w2 (56)... 37 4.3.10 Hasil Uji CBR Laboratorium Sampel Uji SU2w2 (56)... 38 4.3.11 Hasil Uji CBR Laboratorium Sampel Uji SU1w2 (25)... 39 4.3.12 Hasil Uji CBR Laboratorium Sampel Uji SU2w2 (25)... 40 4.3.13 Hasil Uji CBR Laboratorium Sampel Uji SU1w3 (56)... 41 4.3.14 Hasil Uji CBR Laboratorium Sampel Uji SU2w3 (56)... 41 4.3.15 Hasil Uji CBR Laboratorium Sampel Uji SU1w3 (25)... 43 4.3.16 Hasil Uji CBR Laboratorium Sampel Uji SU2w3 (25)... 44 4.4 Pengaruh Penambahan Kadar Air (Water Content) Terhadap Nilai CBR dan Nilai Berat Isi kering (Gamma Dry Density)... 45 4.5 Pengujian CBR Laboratorium Material Crushed Limestone Sukabumi... 49 4.5.1 Hasil Uji CBR Laboratorium Sampel Uji SU1wi (25)... 49 4.5.2 Hasil Uji CBR Laboratorium Sampel Uji SU2wi (56)... 50 4.6 Pengaruh Gradasi Material Crushed Limestone Poorly Graded dan Well Graded... 51 4.7 Evaluasi Nilai CBR Material Crushed Limestone Poorly Graded dan Well Graded Terhadap Kurva Stress (Bearing Value)- Penetration... 53 BAB V SIMPULAN DAN SARAN... 55 5.1 Simpulan... 55 5.2 Saran... 56 DAFTAR PUSTAKA... 57 LAMPIRAN... 58 xii
DAFTAR GAMBAR Gambar 2.1 Schematic Diagram of Plate Loading Test... 6 Gambar 2.2 Correction of Load-penetration Curves... 8 Gambar 2.3 Dry Density Versus CBR... 9 Gambar 2.4 Determining CBR For Water Content Range... 10 Gambar 3.1 Bagan Alir penelitian... 12 Gambar 3.2 Loading Machine... 14 Gambar 3.3 Bongkahan Limestone... 18 Gambar 3.4 Crusher Machine... 18 Gambar 3.5 Ayakan Pada Crusher Machine... 19 Gambar 3.6 Material Crushed Limestone Di Atas Plastik Beton... 20 Gambar 3.7 Hasil Quartering material Crushed Limestone... 20 Gambar 3.8 penimbangan Material Crushed Limestone... 21 Gambar 3.9 Penimbangan Air... 21 Gambar 3.10 Penimbangan Mold dan Material... 22 Gambar 3.11 Mold Pada Mesin CBR... 22 Gambar 3.12 Annular Metal Weight dan Piston Di Atas Material Uji... 23 Gambar 3.13 Pengukuran Penurunan Sampel... 23 Gambar 3.14 Penurunan Sampel Pada Uji CBR... 23 Gambar 4.1 Kurva Grain Size Distribution Curve... 25 Gambar 4.2 Flow Chart for Classifying Coarse-Grained Soils (Gravel)... 26 Gambar 4.3 Flow Chart for Classifying Coarse-Grained Soils (Sand)... 27 Gambar 4.4 Kurva Hubungan Corrected CBR-Dry Density... 29 Gambar 4.5 Kurva Stress-Penetration SU1wi (56)... 30 Gambar 4.6 Kurva Stress-Penetration SU2wi (56)... 31 Gambar 4.7 Kurva Stress-Penetration SU1wi (25)... 32 Gambar 4.8 Kurva Stress-Penetration SU2wi (25)... 33 Gambar 4.9 Kurva Stress-Penetration SU1w1 (56)... 34 Gambar 4.10 Kurva Stress-Penetration SU2w1 (56)... 35 Gambar 4.11 Kurva Stress-Penetration SU1w1 (25)... 36 Gambar 4.12 Kurva Stress-Penetration SU2w1 (25)... 37 Gambar 4.13 Kurva Stress-Penetration SU1w2 (56)... 38 Gambar 4.14 Kurva Stress-Penetration SU2w2 (56)... 39 Gambar 4.15 Kurva Stress-Penetration SU1w2 (25)... 40 Gambar 4.16 Kurva Stress-Penetration SU2w2 (25)... 41 Gambar 4.17 Kurva Stress-Penetration SU1w3 (56)... 42 Gambar 4.18 Kurva Stress-Penetration SU2w3 (56)... 42 Gambar 4.19 Kurva Stress-Penetration SU1w3 (25)... 43 Gambar 4.20 Kurva Stress-Penetration SU2w3 (25)... 44 Gambar 4.21 Kurva Hubungan CBR-Water Content... 46 Gambar 4.22 Kurva Kompaksi... 46 Gambar 4.23 Kurva Hubungan Dry Density CBR Corrected... 48 Gambar 4.24 Kurva Hubungan Dry Density Water Content... 49 Gambar 4.25 Kurva Stress-Penetration SU1wi (25) Well Graded... 50 xiii
Gambar 4.26 Kurva Stress-Penetration SU2wi (56) Well Graded... 51 Gambar 4.27 Kurva Hubungan Dry Density CBR Corrected... 52 Gambar 4.28 Kurva Hubungan Stress (Bearing Value)-Penetration Untuk Material Crushed Limestone Poorly Graded Dan Well Graded.. 53 Gambar L1.1 Kurva Distribusi Ukuran Butir Poorly Graded... 58 Gambar L2.1 Kurva Distribusi Ukuran Butir Well Graded... 59 xiv
DAFTAR TABEL Tabel 2.1 Minimum Load Capacity... 11 Tabel 3.1 Alat-Alat Pengujian CBR... 15 Tabel 4.1 Sieve Analysis Material Padalarang... 24 Tabel 4.2 Sieve Analysis Material Sukabumi... 24 Tabel 4.3 Parameter Material Uji dmax = 4,75mm... 25 Tabel 4.4 Hasil Pengujian Specific Gravity... 27 Tabel 4.5 Hasil Pengujian Water Content... 28 Tabel 4.6 Average Specific Gravity Of Various Rock Types... 28 Tabel 4.7 Tata Cara Penamaan Sampel Uji... 30 Tabel 4.8 Resume Hasil Uji w Initial 56 Blows... 31 Tabel 4.9 Resume Hasil Uji w Initial 25 Blows... 33 Tabel 4.10 Resume Hasil Uji w 1 56 Blows... 35 Tabel 4.11 Resume Hasil Uji w 1 25 Blows... 37 Tabel 4.12 Resume Hasil Uji w 2 56 Blows... 38 Tabel 4.13 Resume Hasil Uji w 2 25 Blows... 40 Tabel 4.14 Resume Hasil Uji w 3 56 Blows... 43 Tabel 4.15 Resume Hasil Uji w 3 25 Blows... 44 Tabel 4.16 Nilai Uji CBR Berdasarkan Penambahan Water Content... 45 Tabel 4.17 Nilai Dry Density Berdasarkan Penambahan Water Content... 45 Tabel 4.18 Nilai Dry Density Maximum dan Water Content Optimum... 47 Tabel 4.19 Nilai Dry Density-CBR Corrected... 47 Tabel 4.20 Resume Hasil Uji w Intial Well Graded... 51 Tabel 4.21 Resume Nilai Dry Density-CBR... 52 Tabel L1.1 Hasil Sieve Analysis Poorly Graded... 58 Tabel L2.1 Hasil Sieve Analysis Well Graded... 59 Tabel L3.1 Hasil Pengujian Water Content... 60 Tabel L4.1 Hasil Pengujian Specific Gravity... 61 Tabel L5.1 Hasil Pengujian CBR SU1wi (56)... 62 Tabel L5.2 Hasil Pengujian CBR SU2wi (56)... 63 Tabel L5.3 Hasil Pengujian CBR SU1wi (25)... 64 Tabel L5.4 Hasil Pengujian CBR SU2wi (25)... 65 Tabel L5.5 Hasil Pengujian CBR SU1w1 (56)... 66 Tabel L5.6 Hasil Pengujian CBR SU2w1 (56)... 67 Tabel L5.7 Hasil Pengujian CBR SU1w1 (25)... 68 Tabel L5.8 Hasil Pengujian CBR SU2w1 (25)... 69 Tabel L5.9 Hasil Pengujian CBR SU1w2 (56)... 70 Tabel L5.10 Hasil Pengujian CBR SU2w2 (56)... 71 Tabel L5.11 Hasil Pengujian CBR SU1w2 (25)... 72 Tabel L5.12 Hasil Pengujian CBR SU2w2 (25)... 73 Tabel L5.13 Hasil Pengujian CBR SU1w3 (56)... 74 Tabel L5.14 Hasil Pengujian CBR SU2w3 (56)... 75 Tabel L5.15 Hasil Pengujian CBR SU1w3 (25)... 76 Tabel L5.16 Hasil Pengujian CBR SU2w3 (25)... 77 Tabel L6.1 Hasil Pengujian CBR SU1wi (25) Well Graded... 78 Tabel L6.2 Hasil Pengujian CBR SU2wi (56) Well Graded... 79 xv
DAFTAR NOTASI Cu Cc CBR0,1 CBR0,2 dmax D60 D30 D10 Gs Koefisien keseragaman (coefficient of uniformity) Koefisien gradasi (coefficient of gradation) Nilai CBR saat penetrasi 0,1inch Nilai CBR saat penetrasi 0,2inch Ukuran butir maksimum Diameter ukuran butir yang berkenaan dengan 60% lebih halus Diameter ukuran butir yang berkenaan dengan 30% lebih halus Diameter ukuran butir yang berkenaan dengan 10% lebih halus Berat jenis tanah w Kadar air (%) dry Berat isi kering (gr/cm 3 ) xvi
DAFTAR LAMPIRAN Lampiran I Hasil Uji Sieve Analysis Poorly Graded... 58 Lampiran II Hasil Uji Sieve Analysis Well Graded... 59 Lampiran III Hasil Uji Water Content Poorly Graded... 60 Lampiran IV Hasil Uji Water Content Well Graded... 61 Lampiran V Hasil Uji Spasific Gravity Poorly Graded... 62 Lampiran VI Hasil Uji Spasific Gravity Well Graded... 63 Lampiran VII Hasil Uji CBR Material Crushed Limestone Specific Gravity Poorly Graded... 64 Lampiran VIII Hasil Uji CBR Material Crushed Limestone Specific Gravity Well Graded... 80 Lampiran IX Contoh Perhitungan... 82 xvii