Long-term evaluation of prestress losses in concrete bridges using long-gauge fiber optic sensors
项目名称: Long-term evaluation of prestress losses in concrete bridges using long-gauge fiber optic sensors
摘要: One of the most important aspects of a prestressed concrete structure is the distribution of the prestressing force along the structure, both at transfer and in the long term. Time-dependent prestress losses are expected to occur in prestressed concrete due to both strand relaxation and dimensional changes in the concrete caused by creep and shrinkage. Thus, these losses are accounted for in the design based on guidelines set by design codes. However, prestress losses larger than predicted by design can have adverse effcts on the structure, where stresses exceed the capacity of the structure at a lower load than predicted. Thus, monitoring of prestress losses will indicate valuable information regarding the performance and health condition of the structure. However, long-term monitoring of the prestress loss is challenging due to (1) variable on-site conditions, in particular (but not only) temperature, that affect both the structure and the monitoring system, (2) rheological effects in the concrete and prestressing strands, such as creep, shrinkage, and relaxation, that interfere with mechanical effects and affect data analysis, (3) presence of pre-release cracks that affects the distribution of the strain in the structure, and also affects the data analysis, and (4) inherent uncertainties related to the reliability and accuracy of the monitoring system and the estimation of mechanical and geometrical parameters of concrete. The outcomes of the project will be (1) the methodology for determination of long-term prestress loss using long-gauge fiber optic sensors, and (2) validation method for long-term temperature and strain measurements used for the analysis.
状态: Active
资金: 149218
资助组织: Office of the Assistant Secretary for Research and Technology
管理组织: New Jersey Department of Transportation
项目负责人: Kasbekar, Nagnath
执行机构: Princeton University
主要研究人员: Glisic, Branko
开始时间: 20160701
预计完成日期: 20180831
实际结束时间: 0
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