详情

Prediction of Moisture Resistance of Polymeric Asphalt Binders Through the Atomic Force Microscopy (AFM) Technique

项目名称：	Prediction of Moisture Resistance of Polymeric Asphalt Binders Through the Atomic Force Microscopy (AFM) Technique
摘要：	Moisture-induced damage in asphalt concrete is a major concern to the transportation agencies. Existing moisture sensitivity tests are mostly conducted at the macro- or micro-level and focused on the qualitative measurements only. The proposed study will investigate the interaction between asphalt binder and aggregates at the interface level measuring adhesion forces between asphalt binder samples and minerals of different chemical compositions using an Atomic Force Microscope (AFM). To this end, all three Arkansas Department of Transportation (ARDOT) approved Performance Grade (PG) binders (PG 64-22, PG 70-22, and PG 76-22) from two different sources and two types of commonly used aggregates (e.g., limestone and sandstone) in Arkansas will be evaluated in the laboratory. Besides the positive impacts of a selective anti-stripping agent (Kao Gripper® X2), the effects of aging (short-term and long-term) on the stripping resistance of binders will be evaluated in the laboratory. In regards to the AFM tests, the tips will be modified with comparable aggregate minerals, thus, the adhesion force between asphalt and minerals will be measured. The adhesion force will then be used to estimate the work of adhesion between asphalt binders and materials resembling the aggregates. The AFM-based nano-level mechanistic properties such as modulus and adhesion over the scanned area of the sample will be recorded in the form of numerical values and images. The captured AFM images will be analyzed by using a commercial tool such as MATLAB® or open-source software (e.g., ImageJ). Routine rheological tests (viscosity, penetration, etc.) will be conducted on asphalt binders as they are indirect indicators of stripping resistance. Elemental analyses (e.g., aromatic hydrogen and aromatic carbon) of solution-state and solid-state asphalt binders will also be tested by using a nuclear magnetic resonance (NMR) spectroscopy. Further, selected aggregates coated with asphalt binders will be tested to evaluate their adhesive and cohesive failures by computing binders’ direct tension using a Pneumatic Adhesion Tensile Testing Instrument (PATTI) device. Furthermore, the striping resistance of fully coated aggregates (loose mixes) will be evaluated by following the Texas Boiling Test (TBT). Two-dimensional images of failure surfaces of the PATTI and post-TBT specimens will be captured and analyzed to determine failure pattern and percentage of retained binder, respectively. Finally, the AFM-based data will be compared with macro-level test data of asphalt binders and loose mixes (asphalt aggregate systems) to draw meaningful conclusions and recommendations. The technical findings of the proposed study are expected to give pavement professionals and researchers a better understanding of moisture-related damage in asphalts at the molecular level. Implementation of the learned knowledge will assist the transportation agencies to avoid premature pavement distresses and save taxpayers’ money. Experimental data gathered from this study are expected to give confidence to state and local transportation agencies, and contractors in the region. The design and quality-control guidelines developed from the proposed study are expected to be implemented by state and industry partners. The proposed study will facilitate in meeting the following objectives of Tran-SET: (i) Introduce and implement cost-effective solutions to the transportation infrastructure backlog of projects; (ii) Develop cost-effective solutions for the construction and maintenance of the transportation infrastructure in metropolitan and rural areas; (iii) Promote workforce development through learning and continuous education. This project strongly supports the Center’s focus areas 4 and 5. This study will develop tools and materials for longer-lasting infrastructure, assess the feasibility of using local industrial wastes, and enhance collaborative records with industry partners. The major benefits of the proposed study are to (a) reuse of waste materials, (b) enhance training opportunities for students in the region and build a future workforce.
状态：	Active
资金：	119121
资助组织：	Office of the Assistant Secretary for Research and Technology
管理组织：	Transportation Consortium of South-Central States (Tran-SET)
项目负责人：	Mousa, Momen R
执行机构：	Arkansas State University
主要研究人员：	Hossain, Zahid
开始时间：	20220401
主题领域：	Highways；Maintenance and Preservation；Materials；Pavements