A review of the feasibility of using crumb rubber derived from end-of-life tire as asphalt binder modifier

Abstract

The use of recycled crumb rubber (CR) in asphalt pavements could be an essential step towards ensuring a more sustainable future in addition to opening a new investment opportunity for global investors. Asphalt modifiers have the ability to enhance the performance of flexible pavements and contribute towards ensuring a more sustainable environment. The utilization of CR produced from end-of-life tires (ELTs) as an asphalt modifier has been shown to enhance asphalt performance with regard to high-temperature rutting and low-temperature thermal cracking due to the remarkable characteristics of the CR. This paper presents the findings of previous studies, including the grinding of ELTs to obtain crumb rubber, the technology employed in the process, and the physical and mechanical properties of the asphalt modifiers. Even though the present study focuses on the application of hot-mix asphalt (HMA), there are other methods, for instance, warm-mix asphalt (WMA), reclaimed asphalt pavement (RAP), and porous asphalt, that used CR as a modifier or as an additive in asphalt binders. A review of the literature suggests that most CR have a good performance and are suitable for use in the top paving layer to reduce noise as well as for other applications.

A Review of the Utilisation of Recycled Waste Material as an Alternative Modifier in Asphalt Mixtures

“…The use of crumb rubber as a modifier to enhance asphalt mixture is one way for ensuring sustainable development. Crumb rubber modifier (CRM) can be a substitute polymer material for enhancing the performance of HMA [5,36]. CRM is a waste scrap tires disposed of in trash dumps, and each year about 1.5 billion tires are manufactured globally [37].…”

“…The use of waste materials in road and pavement construction and throughout the globe has many advantages; among the benefits are the low initial cost to develop infrastructure and that requires advanced technology to prepare and process to be implementable to meet the requirements of pavement materials [5]. Besides, existences waste materials affecting the high costs of pavement construction.…”

“…There are still a few problems faced by many researchers about leaching. For instance, the crumb rubber modified asphalt contains heavy metals such as polycyclic aromatic hydrocarbons (PAHs) and zinc (Zn) due to the high concentration of toxic chemicals that can affect our health and the environment [5]. The result of heavy metal analysis showed that heavy metals in steel slag do not pose any environmental risks or leaching problems when used as aggregates in road applications [137].…”

“…In 2018, the total amount of waste generated, including those generated by households and economic activities in 28 European Union countries, exceed 2.5 billion tons. A total of 285 million tons of scrap tires are discarded in the USA yearly, as an example, as well as used in Portugal, China, Canada, and South Africa [5,6]. Recycled scrap tires can be used as raw materials in the form or crumb rubber and powder rubber [7].…”

Mechanical Performance of Reclaimed Asphalt Pavement Modified with Waste Frying Oil and Crumb Rubber

“…Bilema et al [ 34 ] investigated the considerable effect of CR on the ITS of the asphalt mixture stiffness. Using discarded vehicle tires in pavement construction has environmental benefits and prevents tire stockpile or disposal in the landfill [ 35 , 36 ]. There are two reasons for adding RAP and WFO, together with CR, in HMA, namely to minimise the utilisation of natural resources and discover a sustainable pavement alternative.…”