# Enhancing Asphalt Binder Performance and Storage Stability with Trinidad Lake Asphalt (TLA)
## 2 Experimental Design
### Evaluation of Binder  
#### 2.3.1 Superpave Binder Testing  
Evaluating the performance of asphalt binders throughout various stages of their lifecycle is essential for ensuring the durability and longevity of road structures. A comprehensive investigation was carried out using three standardized test methods prescribed by the American Association of State Highway and Transportation Officials (AASHTO): the Viscosity test (AASHTO T 316) [22], the Dynamic Shear Rheometer (DSR) test (AASHTO T 315) [23], and the Bending Beam Rheometer (BBR) test (AASHTO T 313).  
For rheological evaluation, the Brookfield Rotational Viscometer was utilized in the Viscosity test. A standardized 10.5 g sample of each modified binder type was subjected to viscosity measurements using a number 27 spindle. Assessments were performed at two distinct temperatures--135 \({}^{\circ}\)C and 180 \({}^{\circ}\)C--to cover a range of conditions that binders may encounter. This method provides critical insights into the fluid-like behavior of binders, which is essential for optimal mixing and compaction processes during construction, ensuring the proper workability and uniformity of the asphalt mix.  
The DSR test aimed to capture the viscoelastic characteristics of the binders in their virgin state and after undergoing aging processes: short-term aging (RTFO) and long-term aging (RTFO + PAV). The test was conducted at a frequency of 10 radians per second (approximately 1.59 Hz), which is considered ideal for reflecting the real-world shear-related behaviors of the material. Key parameters such as Complex Shear Modulus (G*) and Phase Angle (8) were computed. The parameter G*/sin \(\delta\) was specifically calculated to assess the material's resistance to rutting, indicating how well the binder can resist permanent deformation under load. Conversely, G*-sin \(\delta\) was measured at 25 \({}^{\circ}\)C to evaluate the potential for fatigue cracking, which is critical for understanding the binder's durability under repeated traffic loading.  
The BBR test focused on evaluating the low-temperature performance of the binders using the RTFO + PAV residual samples. Modified binder beams, with dimensions of 125 \(\times\) 6.35 \(\times\) 12.7 mm, were subjected to creep stiffness (S) measurements at \(-12\)\({}^{\circ}\)C to simulate cold-weather conditions. A 100 g load was applied, and the central deflection of the beam was monitored for 60 s. This test is crucial for assessing the binder's behavior in terms of thermal-induced stresses, primarily its susceptibility to cracking, which can significantly affect pavement integrity in cold climates.  
All tests were conducted in triplicate, and the results were averaged to achieve statistical robustness and reliability. This multifaceted evaluation methodology enabled a comprehensive understanding of the asphalt binders' performance characteristics across various stages of their service life, providing a robust foundation for predicting long-term pavement performance and informing material selection and mix design.