Rutting analysis of 100 mm diameter polypropylene modified asphalt specimens using gyratory and Marshall compactors

Abstract

Compaction technique used in Marshall design does not model the process of actual rolling procedures on site exactly. Carrying out laboratory compaction of dense bituminous mixtures with Superpave gyratory compactors is a more realistic way of simulating actual compaction. In this study, mechanical differences of reference and polypropylene modified asphalt mixtures were compared using Superpave gyratory and Marshall compaction methods by carrying out repeated creep tests utilising universal testing machine. In addition, there is no standard Superpave design procedure for 100 mm diameter samples till date. The other purpose of this study is to propose new standards for the compaction and testing procedures of these 100 mm specimens. Indeed, extensive studies have shown that the design gyration number should be 40 for reference and 33 for polypropylene modified specimens under medium traffic conditions for the similar and specific type of aggregate sources, bitumen, aggregate gradation, mix proportioning, modification technique and laboratory conditions. Moreover, it was shown that, the asphalt samples produced by Superpave gyratory compactor were much resistant to destructive rutting effects than the asphalt specimens prepared by Marshall design.

Laboratory Methods for Assessing the Influence of Improper Asphalt Mix Compaction on Its Performance

“…Additionally, in order to obtain the internal structure of samples comparable to roller compaction, the compaction angle parameter should be appropriately selected, slightly higher than that specified by technical regulations. Taking into account the resistance to rutting, Tapkin and Keskin demonstrated that the samples made in the gyratory press were less susceptible to permanent deformations than those compacted using the Marshall method [18]. Lee et al found that in case of crumb rubber asphalt mixes air void content was significantly dependent on the number of gyratory rotations and directly related to this rutting increased along with air voids [19].…”

Optimization of asphalt and modifier contents for polyethylene terephthalate modified asphalt mixtures using response surface methodology

“…It is worth mentioning that in Marshall compaction method load is perpendicular to compaction axis and relies on falling weight which does not properly simulate field compaction. Thus, recently Marshall compactor has been losing popularity in pavement laboratories in comparison with gyratory compactor [33].…”

Laboratory Evaluation of a Vertical Vibration Testing Method for an SMA-13 Mixture

“…In the past 20 years, China’s traffic has been developing towards “large flow, heavy axle load, high tire pressure”, and some disadvantages of the Marshall method have become obvious [ 10 , 11 , 12 ]. The SMA pavements designed by the Marshall method with early ruts, oil spills, and water seepage indicate that the Marshall compaction standard cannot meet current traffic requirements [ 9 , 13 , 14 , 15 ]. In addition, the Marshall specimen has a poor correlation with the mechanical properties of the site so that the test indicators of the specimen produced by the Marshall method in the laboratory cannot determine the quality of the field pavement very well [ 9 , 13 , 16 ].…”