Swelling and Degradation Characteristics of Crumb Rubber Modified Asphalt during Processing

Abstract

The existence of cross-linked structure in crumb rubber modified asphalt (CRMA) leads to the complexity of its system. According to the preparation test of CRMA under different processing technology, the influence of processing temperature and time on the properties and cross-linking structure of CRMA was analyzed. By analyzing the volume expansion rate of the rubber powder after swelling and the toluene insoluble content attenuation rate, the formation conditions of the macro-level cross-linked structure were determined, and the relationship model between the cross-linked structure and the rubber asphalt performance was established. The results show that the rubber particles can form a continuous phase structure after swelling. At this time, the expansion ratio of the swollen rubber powder was 1.76–2.14. Too high temperature (above 200°C) and too long time (above 60 min) caused serious degradation of rubber. The suitable processing technology was stirring at 180–190°C for 45–60 min.

Penentuan Stabilitas Penyimpanan Aspal Modifikasi Berbasis Karet Alam Padat Jenis Crumb Rubber

“…Dalam penelitian ini perubahan kekerasan aspal setelah penambahan crumb rubber dipengaruhi oleh bergesernya kesetimbangan rasio asphaltene dan maltene. Hal ini dikarenakan penambahan sejumlah crumb rubber menyerap komponen fraksi maltene seperti saturate dan aromatic (Fang et al, 2016;Xia et al, 2021).…”

“…Namun, perlu diperhatikan bahwa degradasi partikel crumb rubber sangat sulit dikontrol. Degradasi yang terjadi pada suhu tinggi dalam tempo waktu yang lama dapat membuat partikel crumb rubber dengan bobot molekul lebih rendah larut dalam fasa aspal (Xia et al, 2021). Akibatnya, partikel crumb rubber dengan bobot lebih rendah dalam jumlah besar mempengaruhi interaksi antar komponen aspal dan membuat kekerasan aspal modifikasi menurun dikarenakan peningkatan proporsi viscous (Shafii et al, 2017;Wang & Ye, 2020;Xie et al, 2019).…”

“…Meningkatnya asphaltene dan menurunnya maltene secara linear dipengaruhi oleh difusi fraksi maltene ke dalam crumb rubber. Difusi fraksi maltene dalam crumb rubber menyebabkan fenomena ekspansi volume (swelling) pada crumb rubber Xia et al, 2021). Fenomena swelling yang terjadi pada crumb rubber oleh fraksi maltene berdampak pada rasio asphaltene dalam aspal yang meningkat dan membuat aspal semakin keras (Ghasemirad et al, 2020).…”

“…Stabilitas penyimpanan aspal modifikasi pada sampel dengan 8% crumb rubber sangatlah buruk, hal tersebut dipengaruhi oleh kompatibilitas antara komponen penyusunnya. Kompatilibilitas aspal modifikasi crumb rubber alam sulit tercapai dikarenakan beberapa faktor yang mempengaruhinya diantaranya fenomena pembengkakan pada crumb rubber (swelling), stabilitas termal dari campurannya, densitas dan viskositas (Lushinga et al, 2020;Wieser, Schaur, & Unterberger 2021;Xia et al, 2021).…”

Performance Optimization Approach of Polymer Modified Asphalt Mixtures with PET and PE Wastes: A Safety Study for Utilizing Eco-Friendly Circular Economy-Based SDGs Concepts

“…A significant number of researchers have studied bitumen alteration order to achieve improved durability and high stability and strength. In the past, countl initiatives have been explored, and scholars have effectively utilized numerous waste m terials e.g., crumb rubber [3,4], nylon and polymer waste [5][6][7], polyethylene [8,9], po propelene [10], recycled PET [11,12], polystyrene [13], and ordinary plastic bottles [14etc. The positive enhancement of all these leading bituminous qualities that are crucial road construction is recognized as a primary goal of all these investigations [17,18]. Po mer matrices of bitumen are one of the most suitable and widely used approaches amo all reported modification approaches [19].…”