Abstract
This article reports on a study of crumb rubber-mediated improvement in bitumen cohesion, analyzed with the UCL method. UCL, a procedure developed to characterize bituminous binders, evaluates the cohesion obtained by adding a certain amount of bitumen or bituminous mastic to a standard mix aggregate. This method was chosen because it can be used to assess bitumen containing crumb rubber added by either the wet or the dry mix process. In the dry mix process crumb rubber is combined with the mix as if it were a fine aggregate; i.e., crumb rubber and binder are blended during mix manufacture, laying and compaction. In the wet mix process, the binder is blended with the crumb rubber prior to mixing with the aggregate; i.e., when added to the mix, it has already been modified. The effect of digesting this dry mixed material prior to use was also analyzed in the present study. A comparison of the dry (with and without digestion) and wet mix processes showed the latter to be more effective, particularly when the crumb rubber was blended with the binder via microscopic dispersion.
Highlights
One possible solution to the problem posed by the growing stockpile of used tyres in Western countries is their use as a component in asphalt mixes.Since the nineteen sixties crumb rubber has been known to improve the rheological properties of bitumen (1) and has been used in different types of applications: modification of bitumen for sealing pavement cracks, binders for surface dressings, sprays and membranes (2)
In proportions ranging from 5 to 30%, is used in asphalt cement in the states of Florida, California and Arizona for both open- and dense-graded mixes, in surface dressings (3). This product has been the object of much research in recent decades and its performance analyzed with classic methods such as the Marshall test (4) as well as trials to evaluate rutting, strength (5) or its contribution to improving the modulus or lengthening the fatigue life of bitumen (6)
Very few studies have been conducted on one of the most important asphalt mix properties impacted by the addition of crumb rubber, namely cohesion
Summary
One possible solution to the problem posed by the growing stockpile of used tyres in Western countries is their use as a component in asphalt mixes.Since the nineteen sixties crumb rubber has been known to improve the rheological properties of bitumen (1) and has been used in different types of applications: modification of bitumen for sealing pavement cracks, binders for surface dressings, sprays and membranes (2). In proportions ranging from 5 to 30%, is used in asphalt cement in the states of Florida, California and Arizona for both open- and dense-graded mixes, in surface dressings (3). This product has been the object of much research in recent decades and its performance analyzed with classic methods such as the Marshall test (4) as well as trials to evaluate rutting, strength (5) or its contribution to improving the modulus or lengthening the fatigue life of bitumen (6). Very few studies have been conducted on one of the most important asphalt mix properties impacted by the addition of crumb rubber, namely cohesion. Sometimes associated with material shear strength, the term cohesion may be used in the context of asphalt mixes to describe the bonding power of binders: this is the meaning attributed to the word in the present study
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
