Abstract

Laboratory experience in Iraq with cold asphalt concrete mixtures is very limited. The design and use of cold mixed asphalt concrete had no technical requirements. In this study, two asphalt concrete mixtures used for the base course were prepared in the laboratory using conventional cold-mixing techniques to test cold asphalt mixture (CAM) against aging and moisture susceptibility. Cold asphalt mixtures specimens have been prepared in the lab with cutback and emulsion binders, different fillers, and curing times. Based on the Marshal test result, the cutback proportion was selected with the filler, also based on the Marshal test emulsion. The first mixture was medium setting cationic emulsion (MSCE) as a binder, hydrated lime, and ordinary portland cement as a filler (7.95% MSCE + 2%HL + 3% OPC). The second mixture used was medium curing cutback (MC-250) as a binder and ordinary portland cement as a filler (5.18% MC 250 + 5% OPC). The indirect tensile strength (ITS) of the samples was measured at 25 ° C. It was found that the cold mix with the MSCE binder had a high ITS value relative to the cold mix with the cutback asphalt binder (MC-250). The dry mixture of MSCE ITS was approximately 3.77 times the dry mixture of MC-250. The MSCE wet mix was about 4.2 times the wet MC-250 mix. Tensile strength ratio result (TSR %) for the MSCE binder mix and the cutback MC-250 binder mix showed that the MSCE mix has a reasonable moisture resistance (77% ) compared to the MC-250 mix (69.2 %). The aging test and aging ratio result showed that asphalt binder oxidation has a significant effect on age-related pavement degradation as it changes the time-temperature relationship depending on the viscoelastic properties of the asphalt binder. The result clearly showed that the MSCE binder mix had a high resistance to aging (440 Kpa) compared to the cutback (MC-250) binder mix (110 Kpa). In contrast, the MSCE aging ratio (90 %) was higher than the MC-250 ratio (85 %).

Highlights

  • MaterialsThe materials used in this investigation are available locally, while the aggregates are typically used for pavement construction in Iraq

  • The second is derived from this test, the tensile strain at failure, which is more useful in predicting cracking potential(O'Flaherty, 2007). The objective of this investigation is to assess the moisture damage and the aging characterization of the cold asphalt concrete mixture of the base course by using two types of binders medium setting cationic emulsion (MSCE) and medium curing cutback (MC-250) through a proper mechanical investigation

  • In Fig 5. for MSCE binder (7.95% MSCE+2 % HL+3 % ordinary portland cement (OPC)) and MC-250 binder specimens (5.18 % MC-250 + 5 % OPC), the result of indirect tensile strength (ITS) tests showed that the cold mixture with MSCE binder is high ITS compared to cold MC-250 and MSCE dry mix is approximately 3.77 times dry MC-250

Read more

Summary

Materials

The materials used in this investigation are available locally, while the aggregates are typically used for pavement construction in Iraq. Badra's quarry supplied us with a crushed and fine aggregate. This kind of aggregate is commonly used for asphalt pavement in the central and southern areas of Iraq. Exhibits the aggregates of the combined gradation applied for the base course. It was classified as a dense gradation. An active filler is known as the filler, which provides hydration in the presence of water in the asphalt mix and can improve the concrete mixture's mechanical properties . In this investigation, two types of fillers were used.

Test Results Medium setting Dark brown liquid
Preparing specimen for Ageing Test
Results and Discussions
CONCLUSIONS
Full Text
Published version (Free)

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 call