Experimental Study On The Slip Resistance, Bolt Relaxation And Fatigue Behaviour Of ASTM A1010 Stainless Steel For Bridge Applications

Unpainted weathering steel has been used extensively in Canada for bridge construction primarily to reduce maintenance requirements and increase durability compared to regular structural steel. However, weathering steel has not performed well in bridges where chlorides from de-icing salts accumulate on the steel, preventing the development of a proper protective patina on its surface.

An alternative solution to this problem is the use of ASTM A1010 stainless steel, which has a chemical composition that enhances corrosion resistance compared to standard weathering steel. Most bridge splice connections consist of gusset plates and high-strength bolts (namely, A325 and A490) designed using the slip-critical method. The Canadian Highway Bridge Design Code (CSA S6-14) specifies an equation for calculating the slip resistance of bolted joints using either A325 or A490 high-strength bolts with regular structural steel under varying surface conditions. However, this equation is not applicable to stainless steel ASTM A1010 due to a lack of research data. Additionally, the fatigue category of A1010 steel is currently unavailable.

Therefore, this research seeks to determine: (i) the slip resistance coefficient of slip-critical joints made of A1010 steel plates; (ii) bolt relaxation of three bolt types, namely A325 plain, A325 galvanized, and A193 B8 stainless steel; and (iii) the fatigue behavior of A1010 stainless steel plates. Identical specimens made of Canadian structural steel plates (CSA G40.21 350W grade) were fabricated and tested to represent the baseline performance for A1010 stainless steel. The experimental findings led to recommendations for the design of slip-critical connections and further research on different fatigue detail categories.