Study Of Flexural RC Member Strengthened With Prestressed Carbon Fiber Reinforced Polymer Composites

In consideration of the rapid development of economic construction and the traffic volume among different regions has been escalating, substantial contribution was invested into traffic construction by government. At the same time of the construction of a large number of highway and railway bridges, because of disrepairing, low standard of original design, etc., many old bridges dissatisfied the current traffic volume and loadage of vehicles and most of them have become bridges in danger and encumbrance of regional economy. So the development and application of a low-cost and effective strengthening technique of bridge is of far reaching importance.Strengthening bridge with CFRP composite was a new strengthening technique which has been developed in the last decade and integrated into the predominance of external directly bonded CFRP composite strengthening technique and prestressing strengthening technique could enhance structural rigidity, make the most of material property and save material and the cost of construction and projects. Prestressed CFRP had a better long-term effect compared with traditional strengthening technique of bridge and can reduce the maintenance cost of strengthening system because of excellent durability of CFRP. Currently, at abroad, in order to impulse the practical application of this technique Britain, America, Canada, Japan, Switzerland and other developed countries have done a great deal of research work in this technosphere; and at home, many research communities including Tsinghua University, TongjiUniversity and Southeast University were involved in this research. Take a view of past research work, much research insufficiency still existed: equipment and craft hardly satisfied operating requirements and have become a bottleneck of the research and application of this technique, experimental study of fatigue property was inadequacy and the mechanism of fatigue failure has been known with non transparency; the dimension of specimen was on the small side and the contribution of size effect was observably, research of long-term performance and refractability was inadequate and restricted to accelerated test and test in natural conditions was lacking, etc.Directed at the inadequacy of past research findings, hereinafter research work done by the author was introduced:...