Use of high-strength steel (HSS) reinforcing bars could provide constructability and economic benefits for the construction of structures, reducing the initial and ultimately the life-cycle cost of bridge and building structural elements. This thesis summarizes work performed in a research project on the use of HSS reinforcing bars for concrete shear friction interfaces. Particularly, this research investigated the behavior of ASTM A706 Grade 80 reinforcing bars. This thesis includes two manuscripts. First, an overview of the testing program and main results are provided in manuscript 1, which describes twenty push-off test specimens that were subjected to interface shear forces along a concrete-concrete interface. The twenty specimens included five specimens of:(i) #4 ASTM A706 Grade 60 reinforcing bars; (ii) #4 ASTM A706 Grade 80 reinforcing bars; (iii) #5 ASTM A706 Grade 60 reinforcing bars; and (iv) #5 ASTM A706 Grade 80 reinforcing bars. Results indicate that the shear interfaces with the #4 reinforcing bars showed no significant difference in peak interface shear force resistance. In addition, the shear interfaces with the #5 reinforcing bars showed significantly higher peak interface shear force resistance. These results are the focus of manuscript 2 that address in more detail the new findings, which ultimately can lead to modifications to current design equations available in US standards and codes. Overall, the results in this thesis show a promising step to understanding and implementing the use of HSS reinforcing bars in shear friction applications so that the full yield strength of the grade of reinforcing steel can be utilized.