Resistance of Rubberized Asphalt Mixture to Aging and Moisture Damage

Abstract

Asphalt pavements in Malaysia suffer severe deterioration, such as raveling and stripping, because the bonding and adhesion between asphalt and aggregate is poor. Heavy rains throughout the year are the main cause of deterioration or a contributing cause to accelerated failure of the pavement structure. Therefore, it is very important to inspect the moisture damage and permeability behavior of asphalt pavement, which can effectively help in a pre-preservation program for asphalt pavement. This study aims to evaluate the effect of adding crumb rubber (CR) on the pavement permeability and moisture damage in highly unfriendly environmental conditions. Laboratory investigation was employed to achieve this aim. The laboratory investigation involved the preparation of two different ACW 14 rubberized asphalt mixtures (unaged and aged). Each type of rubberized mixture contained four CR contents (0%, 5%, 10%, and 15%). The mixtures were tested for air voids, Marshall stability and flow, moisture susceptibility, permeability, and water absorption. The laboratory investigation showed that the CR was appropriate for use up to 10% in asphalt mixtures. There were improvements in the performance of the asphalt mixtures including the Marshall stability, stiffness, durability and resistance against moisture damage. Furthermore, the use of CR prompted better permeability and water absorption. ACW 14 mixture is considered a practically impervious mixture. In conclusion, the application of rubberized pavement can enhance various phases of pavement life and structure by improving the structural performance and reducing environmental impact and landfill issues in the future. ABSTRAK: Turapan asfalt di Malaysia mengalami kemerosotan yang teruk seperti permukaan turapan jalan yang terpecah (rancak) dan berlubang (pelucutan) kerana ikatan dan lekatan antara asfalt dan agregat adalah lemah. Hujan lebat sepanjang tahun adalah punca utama kemerosotan atau penyumbang kepada struktur turapan rosak dengan cepat. Oleh itu, adalah sangat penting bagi memeriksa kerosakan disebabkan lembapan dan sifat kebolehtelapan turapan asfalt ini dapat membantu dengan berkesan dalam program pra-pemeliharaan turapan asfalt. Kajian makmal telah digunakan bagi mencapai tujuan ini. Kajian melibatkan penyediaan dua campuran asfalt bergetah ACW 14 yang berbeza (tidak berumur dan berumur). Setiap jenis campuran getah mengandungi empat kandungan CR (0%, 5%, 10%, dan 15%). Campuran telah diuji samada mempunyai lompang udara, kestabilan dan aliran Marshall, kerentanan lembapan, kebolehtelapan, dan penyerapan air. Kajian makmal menunjukkan CR sesuai digunakan sehingga 10% dalam campuran asfalt. Terdapat peningkatan dalam prestasi campuran asfalt termasuk kestabilan Marshall, kekakuan, ketahanan dan rintangan terhadap kerosakan lembapan. Tambahan pula, penggunaan CR mendorong kebolehtelapan dan penyerapan air. Campuran ACW 14 dianggap sebagai campuran praktikal tidak telap air. Kesimpulan, aplikasi turapan bergetah dapat meningkatkan pelbagai fasa hayat dan struktur turapan dengan menambah baik prestasi struktur dan mengurangkan kesan alam sekitar dan isu tapak pelupusan pada masa hadapan.

Keywords

• Crumb rubber modified bitumen; aged asphalt; dense-graded asphalt mix; rubberized asphalt mixture; moisture damage