Abstract
An asphalt concrete has been modified by adding four polymeric wastes: polyethylene (PE) from micronized containers, polypropylene (PP) from ground caps, polystyrene (PS) from hangers and rubber from end-of-life tyres (ELT). These polymeric wastes were selected according to their availability, homogeneity and economic criteria considering the big amount of material required to build a road.
The dry method has been used to modify the bituminous mixture due to its simplicity and the possibility to be carried out in any asphalt plant without important modifications. This is very important in order to spread the process and recycle the polymeric waste in the same place where it is produced, hence improving the environmental impact.
The reference asphalt mixture and the four modified asphalt concretes have been analysed separately and their performance compared, evaluating their resistance against plastic deformation, stiffness, fatigue resistance and workability. The Master curve and the Black diagram of the mixtures were also calculated.
The results showed that the use of polymeric wastes significantly increased the stiffness of the reference mixture in all cases, but especially when PE, PP and ELT were used. However, none of these materials significantly modifies the fatigue behaviour of the reference mixture. Regarding the resistance against plastic deformation, the use of both PE and ELT led to an increase of the resistance, whereas PP did not modify it and PS decreased it. As for workability, the energy of compaction of the modified mixtures did not suffer any important change. Therefore, according to the results obtained, PE, PP and ELT can be used to modify asphalt mixtures since they improve or do not change their properties. On the other hand, PS should be further studied because of the contradictory results obtained, and only when plastic deformation is not a problem this material could be used.
The dry method has been used to modify the bituminous mixture due to its simplicity and the possibility to be carried out in any asphalt plant without important modifications. This is very important in order to spread the process and recycle the polymeric waste in the same place where it is produced, hence improving the environmental impact.
The reference asphalt mixture and the four modified asphalt concretes have been analysed separately and their performance compared, evaluating their resistance against plastic deformation, stiffness, fatigue resistance and workability. The Master curve and the Black diagram of the mixtures were also calculated.
The results showed that the use of polymeric wastes significantly increased the stiffness of the reference mixture in all cases, but especially when PE, PP and ELT were used. However, none of these materials significantly modifies the fatigue behaviour of the reference mixture. Regarding the resistance against plastic deformation, the use of both PE and ELT led to an increase of the resistance, whereas PP did not modify it and PS decreased it. As for workability, the energy of compaction of the modified mixtures did not suffer any important change. Therefore, according to the results obtained, PE, PP and ELT can be used to modify asphalt mixtures since they improve or do not change their properties. On the other hand, PS should be further studied because of the contradictory results obtained, and only when plastic deformation is not a problem this material could be used.
| Original language | English |
|---|---|
| Pages (from-to) | 1133-1140 |
| Number of pages | 8 |
| Journal | Construction and Building Materials |
| Volume | 112 |
| Early online date | 15 Mar 2016 |
| DOIs | |
| Publication status | Published - 1 Jun 2016 |
| Externally published | Yes |
Bibliographical note
NOTICE: this is the author’s version of a work that was accepted for publication in Construction and Building Materials. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Construction and Building Materials,112, (2016) DOI: 10.1016/j.conbuildmat.2016.02.156© 2016, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Keywords
- Asphalt concrete
- Dry way
- Polyethylene
- Polypropylene
- Polystyrene
- Rubber
- Polymeric waste
- Modified mixture
- Asphalt mixture
- Plastic waste