Corrosion Model Based On Time-dependent Strand

Steel corrosion is one of main durable questions of the reinforced concrete structure, which always is the primary factor that affects the reinforced concrete structure performance. Up to now the research of prestressing tendon's corrosion about prestressed concrete structure is comparative little, but also the research of prestressing tendon's corrosion about prestressed concrete structure under different stress states is far less. Therefore this article unifies The Country Natural Sciences Fund Project "unbonded prestressed concrete structure fatigue and durable research", and studies the corrosion of strand in partially prestressed concrete beam under different stress states; The main findings are presented as follows:1. Analyzing on influencing factors of strand's corrosion initiation time about the reinforced concrete structure and based on the empirical formula of chloride diffusion coefficient under different stress states through the study on experiment dates, proposing calculation model of strand's corrosion initiation time under different stress states and thoroughly discussing the determination and selection of model factors.2. Comprehensive analysis on present research situation of the model of rebar corrosion in contrete at home and abroad and based on calculation model of rebar corrosion rate for chloride penetration into concrete and considering corrosion rate changing with temperature and humidity, establishing calculation model of corrosion rate of strand changing with time in chloride penetration into concrete.3. Using the above models, under different conditions and different stress states and different strand concrete cover thickness, analyzing respectively on the change law of corrosion initiation time of strand and strand corrosion rate about the reinforced concrete structure of diferrent water cement ratio.4. Based on calculation model of corrosion initiation time and corrosion rate of strand. Proposing constitutive equation of corrosion strand basing on chang time.5. Using the finite element software ANSYS is used to study partially prestressed concrete beam under diferrent corrosion condition, and analyzing on the change rule of the supporting capacity and rigidity of the partially prestressed concrete beam changing with corrosion time.