Hatem Seliem, Gregory Lucier, Sami Rizkalla and Paul Zia

Civil Engineering Department. North Carolina State University, USA
E-mail: sami_rizkalla@ncsu. edu


Corrosion of steel reinforcement is considered to be one of the leading causes of deterioration of concrete bridges. This fact has led to the development of numerous technologies such as corrosion – resistant steel that attempt to mitigate this expensive problem. The recent development of high – strength, highly corrosion-resistant steel, commercially known as Micro-composite Multi-Structural Formable (MMFX) steel, is a promising technology. MMFX steel offers its high corrosion resistance without the use of the coating technologies. This characteristic was achieved by proprietary alteration of the steel composition and microstructure. In addition, the control of MMFX steel’s morphology of its microstructure has resulted in its higher strength. Use of MMFX steel could lead to potential savings through using less reinforcement ratios due to its higher strength characteristics and longer service life of structures because of its high corrosion resistance. Recently, many state transportation departments have begun to use MMFX steel as a direct replacement for conventional Grade 60 steel in concrete bridge decks. However, despite these field applications, there is insufficient information about the behavior of such concrete bridge decks utilizing MMFX steel as main reinforcement.

This paper evaluates the use of MMFX steel as main flexural reinforcement in concrete bridge decks in light of test results. Assessment of the effect of the arching action on the strength of bridge decks due to the use of this new steel is also presented.

Experimental Program