Kajian dan perancangan laboratorium penggunaan agregat alam (Relatif bulat) dalam campuran Hot Rolled Sheet-Wearing Course (HRS-WC) :: Studi kasus agregat alam asal Akah, Klungkung, Bali

ARDIKA, Dewa Gede, Dr.Ir. Latif Budi Suparma, M.Sc

2005 | Tesis | Magister Sistem dan Teknik Transportasi

Salah satu persyaratan agregat untuk campuran aspal panas sebagai bahan lapis permukaan perkerasan jalan (wearing course) adalah agregat pecah yang mempunyai kualitas baik. Agregat pecah yang memenuhi persyaratan, semakin lama ketersediaannya akan semakin berkurang, sedangkan di quary Akah, Klungkung, Bali banyak terdapat agregat alam (relatif bulat) tidak bisa dipecah oleh alat pemecah batu (stone crusher) karena lebih kecil dari ukuran batu minimum input. Agregat ini belum digunakan secara maksimal sebagai bahan susun campuran aspal panas untuk perkerasan jalan, walaupun secara fisik termasuk batuan keras. Penelitian ini dilakukan dengan menggunakan agregat alam (relatif bulat) sebagai bahan susun alternatif dalam campuran Hot Rolled Sheet Wearing Course (HRS-WC). Penelitian ini dilakukan dengan menggunakan metode Marshall. Benda uji dibuat dengan memvariasikan prosentase agregat kasar pada campuran HRS-WC, yaitu 50,0% , 39,0% dan 28,0% dengan kadar aspal 7,0%, 7,5%, 8,0%, 8,5% dan 9,0% untuk menentukan kadar aspal optimum sementara, selanjutnya dilakukan uji refusal density untuk menetapkan kadar aspal optimum. Pada kadar aspal optimum, dilakukan uji perendaman untuk mendapatkan nilai Indeks Perendaman dan uji Cantabro untuk mendapatkan tingkat keausan atau kehilangan berat benda uji selama mendapat gaya impact. Hasil penelitian menunjukkan bahwa variasi prosentase agregat kasar pada campuran HRS-WC dengan menggunakan agregat alam (relatif bulat) mempengaruhi kadar aspal optimumnya. Campuran HRS-WC dengan prosentase agregat kasar 50,0%, 39,0% dan 28,0% diperoleh kadar aspal optimum berturutturut 8,0%, 8,3% dan 8,6%. Indeks Perendaman (IP) benda uji dengan prosentase agregat kasar 50,0%, 39,0% dan 28,0% diperoleh nilai IPnya berturut-turut sebesar 92,5%, 93,2% dan 94,1%. Pada pengujian Cantabro pada 300 putaran, nilai keausan atau kehilangan berat benda uji dengan prosentase agregat kasar 50,0%, 39,0% dan 28,0% berturut turut sebesar 1,9%, 1,8% dan 2,1%. Nilai stabilitas setelah Cantabro test untuk benda uji dengan prosentase agregat kasar 50,0%, 39,0% dan 28,0% berturut-turut adalah sebesar 47,9%, 48,4% dan 53,0%. Secara keseluruhan hasil penelitian yang telah dilakukan pada campuran HRSWC yang menggunakan agregat alam (relatif bulat) dari quary Akah, Klungkung, Bali sebagai bahan susun campuran untuk lalulintas rendah (lalulintas <0,5 juta ESA) menunjukkan bahwa, secara umum dengan variasi prosentase agregat kasar yang diteliti memenuhi spesifikasi Departemen Kimpraswil (2002), dengan demikian agregat alam (relatif bulat) dapat digunakan sebagai bahan susun campuran HRS-WC untuk lalulintas rendah.

One of the requirement for hotmix asphalt as material for road pavement wearing course is crushed aggregate with good quality. Recently, crushed aggregate that fulfills the requirement is becoming lack, however in the quary of Akah, Klungkung, Bali there are many of natural aggregate (rounded relatively) can not be crushed by stone crusher due to the smaller size than the minimum input in stone crusher. This aggregate have not been utilized optimally as a raw material hotmix asphalt for road pavement, although phisycally, categorized as hard rock. This study was performed by utilizing the natural aggregate (rounded relatively) as an alternative raw material for Hot Rolled Sheet Wearing Course mixture (HRS-WC). This study was conducted using the Marshall method. The specimens were manufactured by varying the percentage of the coarse aggregate in the mixture of HRS-WC, they were 50.0%, 39.0% and 28.0% with asphalt contents of 7.0%, 7.5%, 8.0%, 8.5% and 9.0% to get the temporarily optimum asphalt content and subsequently the optimum asphalt content was obtained from the refusal density test. At this optimum asphalt content, some speciments were manufactured to perform some other tests, i.e. immersion test to obtain the immersion index and Cantabro test to find out the abrasion value or the mass loss during applying impact force. The results of this investigation were indicated that the variation percentage of coarse aggregate content in the HRS-WC mixture utilizing natural aggregate (rounded relatively) influenced the optimum asphalt content. The percentage of coarse aggregate in the HRS-WC mixtures of 50.0%, 39.0% and 28.0% resulted in the optimum asphalt contents of 8.0%, 8.3% and 8.6% consecutively; the immersion indexes the mixtures were 92.5%, 93.2% and 94.1% respectively. The results from Cantabro test after 300 revolutions indicated that the abrasion or mass loss of the mixtures were 1.9%, 1.8% and 2.1% respectively, whilst the retained stability after Cantabro test of mixtures were 47.9%, 48.4% and 53.0% respectively. Over all, the research results of utilizing the natural aggregate (rounded relatively) from the quary of Akah, Klungkung, Bali as a raw material for the HRS-WC mixture for low-level traffic flow (< 0.5 million ESA), indicated that the mixture with the percentage of coarse aggregate variation investigated were satisfied with the design specification of Kimpraswil Department (2002), hence the natural aggregate (rounded relatively) can be utilized as HRS-WC mixture raw material for low-level traffic flow.

Kata Kunci : Aspal Panas,Agregat Alam,HRS,WC,HRS-Wearing Course, natural aggregate, Marshall Method