Pengaruh penambahan aspal pada karakteristik campuran beton aspal akibat proses penuaan aspal dalam campuran

NGII, Edward, Dr.Ir. Latif Budi Suparma, MSc

2004 | Tesis | Magister Sistem dan Teknik Transportasi

Salah satu perkerasan lentur yang mempunyai nilai struktural tinggi adalah beton aspal (Asphaltic Concrete). Penuaan aspal (ageing) pada campuran beton aspal dapat diakibatkan oleh hilangnya komponen di dalam aspal akibat proses penguapan selama masa konstruksi (shotr-term ageing) dan proses oksidasi selama masa pelayanan. Kedua faktor tersebut dapat meningkatkan viscositas aspal dan akibatnya kekakuan beton aspal semakin tinggi. Hal ini menyebabkan campuran menjadi keras dan rapuh sehingga rentan terhadap kehancuran dan retak. Meningkatkan kadar aspal dalam campuran merupakan salah satu cara untuk mengantisipasi proses ageing dalam campuran aspal (Asphalt Institute, 1997). Penelitian ini bertujuan untuk mengetahui pengaruh penambahan aspal akibat penuaan aspal dalam campuran beton aspal. Penelitian ini dilakukan dengan membuat benda uji STOA dan LTOA berdasarkan metode yang diadopsi dari Strategic Highway Research Program (SHRP), Project A-003A. Variasi penambahan aspal sebesar 0,25%, 0,50%, dan 1,00% dari kadar aspal optimum (5,90%). Spesifikasi campuran beton aspal digunakan Bina Marga 1987. Pengujian kekuatan campuran dilakukan dengan metode Marshall pada benda uji yang tidak dikondisikan dan yang dikondisikan dengan variasi perendaman (Immersion) selama 24, 48 dan 96 jam dan juga dilakukan pengujian Cantabro. Hasil penelitian menunjukkan bahwa berdasarkan karakteristrik Marshall, diperoleh nilai maksimum pada penambahan aspal sebesar 0,50% pada kondisi LTOA, dengan nilai stabilitas (1802,94 kg), flow (3,70 mm), dan MQ (487,77 kg/mm). Pada kondisi STOA, walaupun terjadi penurunan kekuatan pada penambahan 0,50%, namun nilai stabilitas (1371,82 kg), flow (3,50 mm), dan MQ (391,70 kg/mm) yang diperoleh masih memenuhi spesifikasi. Nilai stabilitas sisa (Retained Marshall Stability) setelah perendaman 48 jam pada penambahan tersebut, diperoleh hasil 90,38% pada kondisi STOA dan 69.10% pada kondisi LTOA sedangkan kehilangan berat setelah 300 putaran dengan uji Cantabro diperoleh hasil 4,64% pada kondisi STOA dan 3,52 % pada kondisi LTOA.

One of the type of flexible pavements that has high structural value is the asphaltic concrete. Ageing on the asphaltic concrete mixture is caused by loss of valatile components in asphalt during the conctruction phase (short-term ageing) and oxidation process during the service life (long-term ageing). Both factors can increase the viscosity of the asphalt and furthermore influence in increasing the mix stiffness. This will cause the mixture becoming harder and more brittle, hence causing to disintegration and cracking failures. Adding the asphalt content in the mixture is one of several ways to anticipate the ageing process in the asphalt mixture (Asphalt Institute, 1997). The objective of this research is studying the influence of adding asphalt to the bitumen ageing characteristic at the asphaltic concrete mixture. This research was performed by manufacturing the STOA dan LTOA samples with accordance to the procedure of Strategic Highway Research Program (SHRP) at the project of A-003A. Variation of adding asphalt content were 0.25%, 0.50% and 1.00% to the requirement from the optimum asphalt content (5.90%). The specification of asphaltic concrete mixture based on Bina Marga 1987. The examination of strenght of the mixture was conducted by using the Marshall test method on the unconditioned and conditioned with immersion specimens with the variation of the immersion period of 24, 48, and 96 hours, and also performed the Cantabro Test. The results of this research indicated that base on the Marshall characteristics obtained the maximum value of the addition of aspahalt was at 0.50% for the LTOA condition with the stability value of 1802.94 kg, flow value of 3.70 mm and MQ value of 487.77 kg/mm. At the STOA condition was indicated decreasing strenght of the addition of asphalt at 0.50%, but the stability value of 1371.82 kg, flow value of 3.50 mm and MQ value of 391.70 kg/mm were satisfied to the requirement. The Retained Stability Marshall (RMS) value to the immersion of 48 hour by the addition of asphalt at 0.50% obtained 90.38% of the STOA condition and 69.10% of the LTOA condition. The percentage loss of mass value after 300 times of rotation showed that the addition of asphalt at 0.50% obtained 4.64% for the STOA and 3.52% for the LTOA condition.

Kata Kunci : Beton Aspal, Campuran, Penuaan Aspal, asphalt, asphaltic concrete