Ikatan bahan turapan jalan raya yang baik adalah sangat penting bagi memenuhi cirriciri yang diingini. Namun begitu, ikatan yang sempurna sukar untuk dicapai dan kebanyakan kegagalan jalan raya adalah disebabkan oleh ikatan turapan yang lemah. Akibat daripada ikatan dan kekuatan ricih yang lemah, struktur turapan menjadi lemah seterusnya mempercepatkan proses kegagalan. Kegagalan asfalt bukan sahaja menjejaskan prestasi turapan asfalt tetapi juga menjejaskan struktur turapan dan menyebabkannya gagal dengan cepat. Kajian ini bertujuan untuk mengkaji pengaruh suhu dan kadar pembebanan ke atas kekuatan ricih campuran asfalt. Pengredan agregat jenis konkrit asfalt AC14 yang digunakan dalam kajian ini adalah berdasarkan spesifikasi Jabatan Kerja Raya (JKR). Saiz aggregate yang digunakan dalam penggredan ialah 20, 14, 10, 5, 3.35, 1.18, 0.425, 0.15 dan 0.075 mm. Dalam kajian ini, suhu 10, 20, 30 0C dan kadar pembebanan 20.8, 40.8, 50.8, 60.8 mm/min diterima pakai untuk mengkaji prestasi specimen asfalt melalui ujian Layer-Parallel Direct Shear. Analisis Statistik ANOVA menunjukkan bahawa kedua-dua parameter memberi kesan yang signifikan terhadap kekuatan ricih spesimen asfalt. Keputusan kajian menunjukkan bahawa kadar pembebanan berkadar langsung dengan kekuatan ricih spesimen asphalt. Hal ini disebabkan modulus kekakan asfalt meningkat apabila kadar pembebanan meningkat. Sebaliknya, suhu berkadar songsang dengan kekuatan ricih campuran asfalt. Hal in disebabkan suhu yang semakin meningkat akan menyebabkan modulus kekakuan asfalt semakin merosot dan menjadikan kekuatan ricih asfalt specimen semakin menurun.
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Proper bonding within the pavements is important in ensuring satisfactory pavement performance. However, the proper bonding within the pavement is not always achieved and a number of pavement failures have been linked to poor bond condition. Due to the problems of poor bonding and poor shear strength, pavement structural integrity is compromised and hastens failure. These problems not only reduce pavement serviceability but also adversely affect pavement performance. Therefore, a high shear and interlayer bonding is vital in maintaining the pavements structural and functional integrity. This study focused on the influence of temperature and loading rate on the shear strength of dense mixes asphalt type AC14 prepared according to Jabatan Kerja Raya (JKR) specifications. The nominal maximum aggregate size for designated gradations were set to conform with standards given in the JKR specifications namely 20, 14, 10, 5, 3.35, 1.18, 0.425, 0.15 and 0.075 mm. Temperatures 10, 20, 30 0C and loading rates 20.8, 40.8, 50.8, 60.8 mm/min were adopted to assess the performance of asphalt specimen using the Layer-Parallel Direct Shear test. From statistical analysis using ANOVA, both parameters do give a significant effect on the shear strength of the asphalt specimens. The results indicate that loading rate is directly proportional to the shear strength of asphalt specimens. It is because the stiffness of asphalt mix increase as loading rate increase, hence enhance the shear strength of asphalt specimens. On the contrary, temperature is inversely proportional to the shear strength of asphalt mixes tested. As temperature increase, the stiffness of asphalt mix will reduce due to lower resilient modulus, therefore it reduce the shear strength of the mixes.
Evaluation of direct shear strength of asphaltic concrete using layer-parallel direct shear test_Chou Kuok Lung_A9_2011_NI