College of Graduate Studies: Theses & Dissertations

Term of Award

Summer 2026

Degree Name

Master of Science, Civil Engineering

Document Type and Release Option

Thesis (open access)

Copyright Statement / License for Reuse

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Department

Department of Civil Engineering and Construction

Committee Chair

Junan Shen

Committee Member 1

Xiaoming Yang

Committee Member 2

Soonkie Nam

Abstract

The quantification of low-percentage additives in asphalt binders is challenging due to their minimal concentration and the complex composition of the binder matrix. Zycotherm, a nano-organosilane anti-stripping additive, is typically used in very small dosages (0.05%–0.20%), making its detection and quantification particularly difficult. This study investigated the feasibility of estimating Zycotherm dosage in asphalt binders by examining chemical and rheological and moisture responses. Two asphalt binder grades, PG 64-22 and PG 76-22, were modified with Zycotherm at dosages of 0.05%, 0.10%, 0.15%, and 0.20% by weight of binder, along with corresponding base binders. Laboratory experiments were conducted using Fourier Transform Infrared Spectroscopy (FTIR) to observe chemical-level changes, and Rotational Viscometer (RV), Dynamic Shear Rheometer (DSR), and Tensile Strength Ratio (TSR) tests to examine variations in rheological behavior and moisture response. Multiple samples were prepared for each condition to ensure consistency of the dataset. The results indicate that viscosity and rheological properties vary with zycotherm dosages; however, the trends are not consistent across all dosages and binder types. Non-monotonic behavior and fluctuations are observed, suggesting that these macro-level parameters are influenced by factors beyond additive concentration. Therefore, viscosity and rheological properties do not provide a reliable basis for direct quantification of Zycotherm dosage. However, TSR values show a consistent increase with increasing zycotherm dosage, indicating a clear response of moisture resistance to zycotherm presence. FTIR analysis demonstrated that Zycotherm modification induces measurable changes in the chemical characteristics of asphalt binders. The selected spectral region (1600–1720 cm⁻¹), normalized using the reference region (780–830 cm⁻¹), showed relatively better sensitivity to dosage variation. A general relationship between the FTIR area index and Zycotherm dosage was observed, with PG 76-22 showing a stronger correlation  compared to PG 64-22 (), indicating a more proportional and consistent FTIR response for PG 76-22. However, overlapping absorption bands and the complex nature of asphalt binders limit the complete isolation of additive-specific signals, indicating that binder composition significantly influences the reliability of FTIR-based quantification. FTIR can identify relative dosage trends more effectively than macro-level properties, highlighting the need for improved calibration strategies and more sensitive approaches to quantify such low-percentage materials in asphalt binders.

Research Data and Supplementary Material

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