Cold recycled mixtures for binder courses - laboratory evaluation of mechanical properties
Last modified: 2024-05-06
Abstract
"Cold recycled mixtures composed with cement and bituminous emulsion are nowadays commonly used material for base layer. Typical pavement with cold recycled mixtures usually consists of two asphalt courses (wearing and binding course) constructed over cold recycled base. Therefore the next step in cold recycling is possibility of design of binding courses with recycled materials, but with potential to obtain high quality mixtures similar to commonly used asphalt concretes. In this case, typical new pavement structure would be designed as two cold recycled mixtures (for base and binding course) covered by wearing course.
This publication presents both basic and advanced laboratory results for cold recycled binding course. Cold recycle binding course is characterized by more strict requirements for base material gradation and more strict ranges for possible properties. Also the composition of binding agents is selected to be as similar as for typical asphalt concretes. In laboratory following test were performed: volumetric properties, resistance to water and frost action, viscoelastic properties (dynamic modulus, phase angles) and resistance to fracture in SCB test. For comparison, the same test were performed for asphalt concrete for binder course and for selected test also for cement bound mixtures.
Obtained results indicate that cold recycled mixtures for binder course are located between typical asphalt concretes and cement bound mixtures, characterizing by both high bearing capacity and sufficient viscoelastic properties. In the case of resistance to water and frost, cold recycled mixtures are characterized by ratio between 75-85%. Cold recycled mixtures showed good fracture resistance results in SCB test in comparison to other tested mixtures. Laboratory stage of research confirmed very good properties of cold recycled binding course and open possibility for further steps to construct and evaluate the designed mixtures on real life conditions on trial section in real environmental conditions. "
This publication presents both basic and advanced laboratory results for cold recycled binding course. Cold recycle binding course is characterized by more strict requirements for base material gradation and more strict ranges for possible properties. Also the composition of binding agents is selected to be as similar as for typical asphalt concretes. In laboratory following test were performed: volumetric properties, resistance to water and frost action, viscoelastic properties (dynamic modulus, phase angles) and resistance to fracture in SCB test. For comparison, the same test were performed for asphalt concrete for binder course and for selected test also for cement bound mixtures.
Obtained results indicate that cold recycled mixtures for binder course are located between typical asphalt concretes and cement bound mixtures, characterizing by both high bearing capacity and sufficient viscoelastic properties. In the case of resistance to water and frost, cold recycled mixtures are characterized by ratio between 75-85%. Cold recycled mixtures showed good fracture resistance results in SCB test in comparison to other tested mixtures. Laboratory stage of research confirmed very good properties of cold recycled binding course and open possibility for further steps to construct and evaluate the designed mixtures on real life conditions on trial section in real environmental conditions. "
Keywords
Cold recycled mixtures; binder course; dynamic modulus; SCB fracture test
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