The preflex composite beam made by unite the hunch concrete represtressing the lower casing concrete

摘要

This design compensates for the welding residual stress of steel and the compressive stress loss of lower casing concrete due to creep and dry shrinkage of concrete. The method of introducing additional compressive stress into the lower casing concrete by applying upward load by installing branch points such as copper barges is used. However, the free compressing stress can be introduced into the lower casing concrete without any additional material or additional process. The present invention relates to a flex composite beam. To this end, this design applies a force to the center of the composite beam on the ground, not on the alternating or pier, to introduce additional compressive stress to the lower casing concrete, and places hunt and abdominal concrete for introducing additional prestressing under force. After curing, the force is removed to compensate for the reduced compressive stress of the lower casing concrete. According to this design, it is more concise than the conventional manufacturing method and the material usage can be significantly reduced.