Penggunaan agregat kasar bernilai abrasi tinggi pada campuran Split Mastic Asphalt (SMA) 0/11

SUSANTI, Dr.Ir. Latif Budi Suparma, MSc

2004 | Tesis | Magister Sistem dan Teknik Transportasi

Split Mastic Asphalt (SMA) adalah lapis fleksibel dengan gradasi terbuka yang mempunyai stabilitas dan durabilitas tinggi. Properti agregat yang digunakan dalam campuran mempengaruhi kinerja perkerasan. Seiring dengan tuntutan kebutuhan agregat dimasa yang akan datang dan dalam mengatasi kelangkaan agregat dengan nilai abrasi yang disyaratkan, maka pada penelitian ini agregat kasar yang digunakan sebagai bahan campuran SMA mempunyai nilai abrasi tinggi untuk mengetahui karakteristik campuran SMA. Penelitian ini diawali dengan pemeriksaan aspal, agregat kasar dan halus, kemudian ditentukan kadar aspal optimum untuk campuran bernilai abrasi tinggi dan campuran bernilai abrasi rendah dengan mengikuti prosedur NAPA. Agregat bernilai abrasi tinggi (51,8%) berasal dari Sungai Krasak dan agregat bernilai abrasi rendah (23,2%) dari Sungai Clereng, dengan 3 variasi gradasi yaitu batas maksimum, nilai tengah dan minimum dari gradasi spesifikasi Kimpraswil 2000, yaitu dengan agregat kasar sebanyak 79%, 74% dan 69% masing-masing untuk variasi-1, variasi-2 dan variasi-3. SMA bernilai abrasi tinggi selanjutnya dilakukan pengujian metode Marshall, Cantabro untuk mengetahui kekuatan terhadap impact, indirect tensile strength (ITS) untuk mengetahui kuat tarik, dan draindown untuk mengetahui pengaliran aspal. Marshall dan ITS diuji pada benda uji kontrol dan perendaman 24 jam untuk mengetahui pengaruh air terhadap karakteristik campuran. Hasil penelitian menunjukkan campuran SMA berabrasi tinggi pada kadar aspal optimum sebesar 8,7% (variasi-1), 7,9% (variasi-2) dan 6,9% (variasi-3) terjadi peningkatan stabilitas seiring dengan pengurangan prosentase agregat kasar, disamping itu stabilitas campuran berabrasi tinggi (1178 kg, 1425 kg, 1592 kg) lebih tinggi dibandingkan campuran berabrasi rendah (875kg, 1405kg, 1405kg), sebagai akibat dari rendahnya nilai VMA (Krasak: 18,72%, 16,60%, 15,53% dan Clereng: 23,13%, 19,58%, 17,41%) dan VITM (Krasak: 4,83%, 3,97%, 3,63% dan Clereng: 5,99%, 4,73%, 4,30%). Prosentase kehilangan berat uji Cantabro sebesar 2,08%, 2,85% dan 2,99%, tetapi stabilitas sisa pasca Cantabro terjadi penurunan menjadi 39,2%, 37,9% dan 43,4%. Akibat perendaman terjadi penurunan TSR (tensile strength ratio) menjadi 47,7%, 48,1% dan 67,9% dan penurunan stabilitas (IP) menjadi 80,95%, 81,15%, 85,16%. Secara keseluruhan bahwa penggunaan agregat berabrasi tinggi untuk campuran SMA tidak dapat untuk melayani lalulintas tinggi berdasarkan spesifikasi Departemen Kimpraswil 2000.

Split Mastic Asphalt (SMA) is a flexible pavement with open graded which has the high stability and durability. Aggregate property is used in this mixture influenced pavement performance. Due to increasing demand of aggregate in the future as well as to cope with the problem of the lack aggregate deposite and the abrasion value requirement, the coarse aggregate used in this research as the material of SMA mixture retains high abrasion value to find out the characteristics of SMA mixture. The first step of this research started by testing the asphalt, coarse aggregate and fine aggregate, following with determining the optimum asphalt content for the high and the low abrasion value mixture according to the NAPA procedure. The aggregate of high abrasion value (51.8%) from River Krasak and aggregate of low abrasion value (23.2%) from River Clereng, with three gradation variation; maximum limit, medium value and minimum of specification gradation of Kimpraswil 2000; with coarse aggregate content of 79%, 74%, and 69% of each variation 1, 2, and 3 respectively. The mixture with high abrasion value has been conducted tests of Marshall Test, Cantabro test to find out the strength impact, ITS (indirect tensile strength) to get tensile strength, and draindrown to determine asphalt drainage. Marshall and ITS tests were performed for testing the standard specimens and 24 hour of immersion specimens studing the water effect of mixture characteristic. The results of this research showed that the mixture of high abrasion value of the optimum asphalt content were at 8.7% (variation 1), 7.9% (variation 2), and 6.9% (variation 3), it was shown that the stability increase in decreasing the coarse aggregate percentage, beside that the mixture stability of high abrasion value (1178 kg, 1425 kg, 1592 kg) compared to low abrasion value (875 kg, 1405 kg, 1405 kg) as the affect of the low VMA value (Krasak: 18.75%, 16.60%, 15.53%, and Clereng: 23.13%, 19.58%, 17.41%) and VITM (Krasak: 4.83%, 3.97%, 3.63%, and Clereng: 5.99%, 4.73%, 4.30%). The percentage of weight loss of Cantabro test were 2.08%, 2.85%, and 2.99%, on the other side, the decrease of the stability value of pasca Cantabro Test were to 39.2%, 37.9%, 43.4%. Due to the immersion, the tensile strength ratio were 47.7%, 48.1% and 67.9%, and the immersion index were 80.95%, 81.15%, 85.16%. In overall, utilizing coarse aggregate with high abrasion value in SMA mixture can not carry out the heavy load traffic based on the specification of Kimpraswil Department 2000.

Kata Kunci : Aspal Jalan,Campuran SMA,Agregat Kasar Abrasi Tinggi