Title:
Creep-Fatigue Interaction for CFRP-Prestressed Concrete Bridge Girders (Prepublished)
Author(s):
Yail J. Kim, Jun Wang, Woo-Tai Jung, Jae-Yoon Kang, and Jong-Sup Park
Publication:
Structural Journal
Volume:
Issue:
Appears on pages(s):
Keywords:
carbon fiber-reinforced polymer (CFRP); creep; fatigue; prestressed concrete; time-dependent behavior
DOI:
10.14359/51743304
Date:
10/9/2024
Abstract:
This paper presents the implications of creep-fatigue interactions for the long-term behavior of bulb-tee bridge girders prestressed with either steel strands or carbon fiber-reinforced polymer (CFRP) tendons. A large amount of weigh-in-motion data incorporating 194 million vehicles are classified to realistically represent live loads. Computational simulations are conducted as per the engagement of discrete autonomous entities in line with time-dependent material models. In general, the properties of the CFRP tendons insignificantly vary over 100 years; however, the stress range of CFRP responds to fatigue cycles. Regarding prestress losses, the conventional method with initial material properties renders conservative predictions relative to refined approaches considering time-varying properties. The creep and fatigue effects alter the post-yield and post-cracking responses of the steel- and CFRP-prestressed girders, respectively. From deformational capability standpoints, the steel-prestressed girders are more vulnerable to fatigue in comparison with the CFRP-prestressed ones. It is recommended that the fatigue truck and the compression limit of published specifications be updated to accommodate the ramifications of contemporary traffic loadings. Although the operational reliability of both girder types is satisfactory, the CFRP-prestressed girders outperform their steel counterparts in terms of fatigue safety. Technical findings are integrated to propose design recommendations.