Assessing the Elastic Moduli of Pavement Marking Tapes using the Tape Drape Test

Temporary pavement marking (TPM) tape adhesion with roadway surfaces is critical for tape performance. The two main TPM performance issues both stem from the adhesive strength. Weak adhesion results in premature detachment and excessive adhesion requires extensive removal processes that often leave ghost markings, both of which can cause dangerous confusion in road construction zones. Tape adhesion is directly related to the elastic modulus (E) role= presentation \u3e(E) of TPM tapes. Thus, accurate characterization of E role= presentation \u3eE before tape installation is essential to fully understand and predict the adhesion performance and ultimately the durability of TPMs. To determine the most appropriate E role= presentation \u3eE characterization technique for three different commercial TPM tape brands, two commonly used techniques—tensile and three-point bend testing—were compared with a less common technique, the Peirce cantilever testing or “Tape Drape Test” (ASTM D1388-18). The Tape Drape Test was the only method that accurately characterized E role= presentation \u3eE of tapes with raised surface features. Measured E role= presentation \u3eE values from tensile and three-point bend testing showed significant variation caused by the structural features of the tapes. The Tape Drape Test, which can be implemented quickly in the field before tape installation with little equipment, effectively characterized E role= presentation \u3eE for all the tapes to inform tape adhesion performances and installation procedures

Mechanically Characterizing Polymeric Materials Using Buckling Mechanics and Mechanophores

In order for new materials to be implemented into industrial practice, rigorous characterization and performance assessment must be conducted. The ability to accurately characterize and assess these new materials is directly related to the delay between material development and implementation. Traditionally utilized characterization techniques may not be an appropriate method to characterize a material or materials system, thus warranting the development of new characterization and performance assessment techniques. For swift implementation of novel materials and materials systems, characterization and performance assessment methodologies must be developed simultaneously. While many new materials characterization techniques have been developed over the past years, one area in need of further development is mechanical characterization techniques. For newly developed materials, understanding and accurately predicting the mechanical performance is essential for personnel safety and for preventing unexpected materials failure. The work presented here focuses on the development of mechanical characterization techniques employing two strategies: repurposing old tools and techniques to solve new problems and developing new tools and techniques to solve old problems. By using the first strategy, classical buckling mechanics were deployed to create a robust elastic modulus characterization technique for brittle, glassy polymer films, and a technique developed to determine the “handle” or drape of textiles was repurposed to characterize the elastic modulus of temporary pavement marking tape to assess adhesion performance. Through the second strategy, newly developed molecules called Mechanophores (MP) that exhibit a color or fluorescence change upon the application of a mechanical stimulus are being considered for self-reporting damage sensing applications in polymeric material systems. The elicited fluorescent MP response increases with applied stress allowing for real time damage sensing that can prevent unexpected material failure. Here, a methodology is presented that calibrates the fluorescence MP response to applied stress. These strategies and methodologies can either be utilized or used as inspiration by other engineers for the development of material characterization methods for the rapid implementation of new materials into industrial practices

Mechanical Properties of Durable Pavement Marking Materials and Adhesion on Asphalt Surfaces

Mechanical properties of commercially available temporary pavement marking (TPM) tapes and thermoplastic materials used as permanent pavement markings (PPM) were investigated using the non-destructive Tape Drape Test and conventional mechanical testing. The impact of temperature and aging on the adhesion of TPM tapes and thermoplastic PPM applied to asphalt core surfaces with various surface roughness and treatments was determined using a modular peel fixture and shear adhesion tests. The adhesion of TPM tapes to model smooth surfaces decreased as surface temperature was increased from 0 to 40°C (32 to 104°F). For some tapes, reduced adhesion and brittle broken fracture were observed at the lowest investigated temperature of -20°C (-4°F). The adhesion of tapes applied to asphalt decreased significantly within 1 week of aging at -25°C (-13°F). Ghost markings were more likely at higher aging temperatures. For PPM thermoplastics, better adhesion to asphalt was observed for higher application temperatures and rougher surfaces. Asphalt emulsion treatments reduced the adhesion of thermoplastics and increased the likelihood of adhesive failure after 5 months of aging at -25°C (-13°F). More ductile PPM thermoplastic materials had better adhesion to both smooth and rough asphalt surfaces compared to thermoplastic materials with a more brittle mechanical response