Study of crumb rubber materials as paving asphalt modifiers

Abstract

Waste tire crumb rubber materials (CRM) were used to modify paving asphalts. The mixing time, hot-storage stability, Superpave grades, pumping and handling properties, phase separation tests, and repeated creep properties of the modified asphalts were studied using base asphalts of different hardness. Applying the Long-Term Pavement Performance (LTPP) program and the Transportation Association of Canada (TAC) model, optimal levels of CRM and suitable base asphalts were selected for the climatic conditions of Lethbridge, Alberta, Canada. High-temperature grade bumping protocol, regarding traffic volume and speed, was also considered. With joint efforts from the Tire Recycling Management Association of Alberta (TRMA), Husky Energy, and the City of Lethbridge, three test sections in different Lethbridge locations with various traffic volumes were paved from the years 2003 to 2005. So far, the City of Lethbridge is pleased with the initial performance of the test sections.Key words: waste tire, crumb rubber materials (CRM), paving asphalt, recycled, modification, Superpave, repeated creep, field test.

Rheological properties of asphalts modified by waste tire rubber and reclaimed low density polyethylene

“…The use of rubber as asphalt modifier in road constructions can date back to 1960, when Charles McDonald first added crumb rubber in asphalt mixtures to improve the pavement performance [7,11,15]. During the last decades, crumb rubber modified asphalt binder has been widely used as road paving materials worldwide [20].…”

Noise Reduction Properties of an Experimental Bituminous Slurry with Crumb Rubber Incorporated by the Dry Process

“…One solution which is being researched in order to reduce the so-called tire/road noise, is the development of more elastic surfaces to minimize the impact effect through the incorporation of crumb rubber (CR) from wasted automobile tires. In the last decades, various technical and scientific studies have reported that the addition of CR and other polymers improves mechanical properties of the road surface, such as permanent deformation, stiffness or reflective and thermal cracking [9][10][11][12][13]. Usually, the incorporation of CR as modifier of the bituminous binder, via the wet process, has reflected an improvement of the acoustic performance of the asphalt roads, obtaining a decreasing of the generated sound levels in relation to the percentage of rubber employed in the binder and/or the maximum aggregate size (macrotexture) used in the mixture [14][15][16][17].…”

Innovative Application of Scrap-Tire Steel Cords in Concrete Mixes

“…The coarse aggregate had specific gravity of 2.65 with a maximum aggregate size of 14.6 mm. The steel cords used in this study consisted of steel wires of varying lengths (5-85 mm) and diameters of 0.2-1.3 mm with an average density of approximately 2.7 g/cm 3 , as well as rubber particle bonded to the wires. Table 2 shows the properties of recycled tire materials.…”

“…Scrap tires were initially recycled for their rubber contents because of the environmental threats associated with; their proper disposal has attracted the attention of many researchers in the last years [1][2][3][4][5].…”