Multi-Scale Rheo-Mechanical Study of SMA Mixtures Containing Fine Crumb Rubber in a New Dry-Hybrid Technology

Abstract

Aiming to study the rheo-mechanical effects of fine crumb rubber into gap graded stone mastic asphalt (SMA) mixtures, a multi-scale experimental approach was adopted. Therefore, in the perspective of the reuse of end of life tires’ in asphalt layers, the adopted new dry-hybrid technology effects have been investigated from the mastic, mortar and mixture points of view. The new rubberized asphalt production technology allows the use of rubber powder as filler, the rubber amount optimization being validated through multi-scale performance tests. Mastics and mortars’ complex modulus measured with dynamic shear and torsional tests were related to the mixture stiffness modulus recorded in direct tension-compression mode. The rheological properties of mastic are strictly influenced by the rubber presence, and consequently the asphalt mixtures stiffness and thermo-sensitivity are connected to the mastic and mortar rheo-mechanical behavior. Results are consistent through the adopted approach and reveal that with the new dry-hybrid technology, overcoming the wet and dry limits, it seems to be possible obtaining more durable and eco-friendly bituminous pavement layers.

Evaluation and Correlation Analysis of the Rheological Properties of Ground Tire Rubber and Styrene Butadiene Styrene Compound-Modified Asphalt

“…In order to improve this situation, road engineering researchers have been utilizing waste tires in road construction [ 3 ]. At present, the application of waste tires in pavement construction takes on many forms: roadbed restraint with intact tires, reinforcement with tire strips and nets, toughening, and vibration damping with waste tire particles, as well as modification and enhancement with waste tire powder [ 4 ], as shown in Figure 1 . Adding ground tire rubber (GTR) can significantly improve the high-temperature and low-temperature performance and the fatigue performance of asphalt binders [ 5 ].…”

Effect of Addition of Rubber Granulate and Type of Modified Binder on the Viscoelastic Properties of Stone Mastic Asphalt Reducing Tire/Road Noise (SMA LA)

“…The use of multi-scale performance tests to determine the optimal amount of crumb rubber in SMA mixtures as a material that partially replaces the filler and sand fraction, forming with asphalt mastic and mortar, respectively, is discussed in [ 17 ]. The effects of using New Dry-Hybrid Technology have been investigated from the mastic, mortar, and mixture points of view.…”