The College of Engineering at the University of Baghdad witnessed the public discussion of the master’s student (Wasnaa Jassim Mohammed) from the Civil Engineering Department on his thesis entitled (Investigating the Moisture Susceptibility Resistance of Sustainable Asphalt Mixtures Modified with Silica Fume Additive) on Monday, 4/11/2024, in Dr. Khaled Shaker Hall. Under the supervision of (Prof. Dr. Mohammed Qadir Ismael)
The research aims to investigate the effectiveness of utilizing recycled concrete aggregate (RCA) in different percentages (0%, 15%, 30%, and 45%) by weight of normal coarse aggregate with addition silica fume (SF) at various percentages of (0%, 3%, 6%, and 9%) by weight of the binder to create highly resistant hot asphalt mixtures to moisture
The study’s findings indicated that 30% RCA with 6% SF, is the best amount of RCA and SF that should be added to asphalt mixtures. This percentages recorded highest increase for tensile strength ratio (TSR) and index of retained strength(IRS), by 13.72% and 14.13%, respectively. This demonstrated a stronger resistance to moisture damage.
The research came out with a set of recommendations, including
- Investigate the impact of various asphalt cement grades on the characteristics of hot or warm mix asphalt with varying proportions of RCA and SF.
- Studying how the rutting resistance and fatigue behavior of mixes with various percentages of RCA are affected when SF is added to asphalt together with additional materials like styrene-butadiene-styrene (SBS) or fibers.
- A study case is necessary to assess the performance of mixes with RCA and SF under traffic and environmental effects.
After scientific discussion by the respected members of the discussion committees and listening to the researcher’s defense, the researcher obtained a master’s degree in civil engineering/Roads and Transportation with a grade of (Excellent)
