DURABILITY AND PRESTRESS LOSS IN HIGHWAY BRDIGE BEAMS PRESTRESSED WITH CFRP STRANDS
The use of carbon fiber reinforced polymer(CFRP)strands in precast prestressed bridge beam construction requires careful consideration for the long-term performance of CFRP materials.In regions with harsh winters,repeated freeze and thaw cycles can lead to deterioration of the structural elements.On the other hand,warm weather can impact the mechanical properties and effective prestressing force in CFRP strands.Through this experimental study,unbonded CFRP specimens prestressed to various levels of prestressing force were subjected to harsh winter and summer conditions for 19 months.The monitoring curves were compared with those of identical specimens preserved in controlled laboratory conditions.In a parallel investigation,five decked bulb T beams prestressed with CFRP strands were designed,constructed,and tested under a four-point-load setup to evaluate the effect of temperature and environmental conditions on the prestress loss in bonded CFRP strands.One beam was tested to failure 28 days after construction.Two beams were retained outdoors and were tested after one and two years,while the last two beams were preserved in controlled laboratory conditions and were also tested after one and two years.Test results showed that parameters such as relaxation rate and prestress loss in CFRP strands can be accurately estimated and implemented in the design of bridge beams.In addition,although seasonal temperature changes do seem to temporarily affect the level of the effective prestressing force,they do not seem to induce any permanent damage or alteration in the mechanical properties of CFRP strands.
bridge non-corrosive carbon-fiber prestressing durability
Nabil Grace Tsuyoshi Enomoto Mohamed Mohamed Kerolos Abdo Mena Bebawy
College of Engineering,Lawrence Tech.University,21000 West 10 Mile Rd.,Southfield,MI 48075,USA Tokyo Rope USA Inc,8301 Ronda Dr.,Canton,MI 48187,USA Civil & Architectural Eng.Dept.,Lawrence Tech.University,21000 West 10 Mile Rd.,Southfield,MI 48075,
国际会议
新加坡
英文
1-5
2017-07-19（万方平台首次上网日期，不代表论文的发表时间）