Skip to Main Content
Frequently Asked Questions
Submit an ETD
Global Search Box
Need Help?
Keyword Search
Participating Institutions
Advanced Search
School Logo
Files
File List
ohiou1357317910.pdf (2.94 MB)
ETD Abstract Container
Abstract Header
The Use of Atomic Force Microscopy in Evaluating Warm Mix Asphalt
Author Info
Abu Qtaish, Lana
Permalink:
http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1357317910
Abstract Details
Year and Degree
2013, Master of Science (MS), Ohio University, Civil Engineering (Engineering and Technology).
Abstract
In this thesis, atomic force microscopy (AFM) was used to investigate moisture damage and the healing characteristics of warm mix asphalt (WMA) and compare it to those of hot mix asphalt (HMA) at the nano-scale level. Furthermore, AASHTO T 283 test method was used to evaluate moisture damage in WMA and HMA mixtures at the macro-scale level. AFM Force spectroscopy technique was used to measure the cohesive and adhesive forces in the asphalt mix using a group of chemically functionalized AFM tips under dry and wet conditions while tapping mode imaging technique was used to obtain topographic and phase images for the asphalt binders. Two types of performance grade binders were evaluated in this study: a neat asphalt binder PG 64-22 and a polymer modified binder PG 70-22M. Four WMA technologies were investigated: Advera, Sasobit, Evotherm Advera, and foamed WMA. The results of the AFM imaging showed “bee- like” structures in most of the tested samples. Sasobit additive was the only WMA technology that significantly affected the “bee-like” structures by increasing their lengths and reducing their widths. In addition, Sasobit resulted in increasing the relative stiffness of dispersed domains containing the ‘bee-like’ structure in comparison with the flat asphalt matrix for both types of binders. Based on the force spectroscopy tests the polymer modified PG 70-22M HMA and WMA samples were found to be less susceptible to moisture damage compared to the PG 64-22 samples. The inclusion of WMA additives improved the adhesive forces for both types of binders while its effect on the cohesive forces was less significant. Sasobit had the least improvement on the adhesive forces and resulted in reducing the cohesive forces in both types of binders this could be related to the lower indirect tensile strength that were obtained for the Sasobit mixtures. The adhesive forces were reduced after conditioning of the control and WMA PG 64-22 binders. Sasobit and Advera had the highest reduction which could be related to the inferior tensile strength ratio obtained from their mixtures. However, Evotherm and control PG 64-22 adhesive and cohesive forces were not significantly affected by conditioning. AFM results also showed a good correlation between the adhesive force results and AASHTO T 283 results. The healing experiments showed that most WMA processes improved the healing rate except Sasobit which reduced the crack closure rate. Finally, this study provides a new approach for evaluating the healing characteristics of asphalt binder and a better understanding of the WMA characteristics at a nano-scale level. In addition, it demonstrated the capability of the AFM to characterize and examine the nano-structural properties of asphalt paving materials.
Committee
Munir Nazzal, Ph.D (Advisor)
Subject Headings
Civil Engineering
Keywords
warm mix asphalt
;
atomic force microscopy
;
moisture damage
;
healing
;
force spectroscopy
;
AASHTO T 283
Recommended Citations
Refworks
EndNote
RIS
Mendeley
Citations
Abu Qtaish, L. (2013).
The Use of Atomic Force Microscopy in Evaluating Warm Mix Asphalt
[Master's thesis, Ohio University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1357317910
APA Style (7th edition)
Abu Qtaish, Lana.
The Use of Atomic Force Microscopy in Evaluating Warm Mix Asphalt.
2013. Ohio University, Master's thesis.
OhioLINK Electronic Theses and Dissertations Center
, http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1357317910.
MLA Style (8th edition)
Abu Qtaish, Lana. "The Use of Atomic Force Microscopy in Evaluating Warm Mix Asphalt." Master's thesis, Ohio University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1357317910
Chicago Manual of Style (17th edition)
Abstract Footer
Document number:
ohiou1357317910
Download Count:
754
Copyright Info
© 2013, all rights reserved.
This open access ETD is published by Ohio University and OhioLINK.