Research On Losses Of Prestress In The Prestressed Concrete Component Subjected To Freeze-Thaw Cycle

Application of prestressed technology makes a lot of architectural form that difficult to achieve as possible, it can meet the requirements large span and large standard width of a room of the people better. For example: Barcelona Trade Center in Spain is a large span building, one span is 70 meters, another span is23 meters; The European Parliament in Strasbourg Center, according to the seismic requirements, the project must be a jointless annular construction, only applying the ring prestress on the floor can meet the requirements of the stress and deformation in the quake. Prestressed concrete structures have a lot of advantages, it has good crack resistance and small deformation, it also can reduce the weight of structure by the way of saving building materials. A lot of security of structures has been greatly improved because of the existence of the prestressed structure. However, the effective prestress in the structure of the stress decreased gradually with the time increasing. When meet the adverse external environment, it will decline faster.Concrete is one of the most widely used materials in structural engineering.Due to the concrete itself is the thermal inertia material, so the concrete structure will produce nonlinear temperature field with the temperature variation,more and more scholars have begun to pay attention to the potential threats bythe temperature effect of structural engineering. Recently, the topic of the durability of the concrete becomes a research hotspot, it includes the concrete carbonation, corrosion, freeze-thaw cycles, surface erosion and so on. The freeze-thaw cycle is an important direction of research on the durability of the concrete. For the prestressed concrete structure in the natural envirement from winter to summer, from hot to cold, it leads to the decrease of the elastic modulus of concrete, brings the loss of prestress that can not be ignored, the reliability and durability of the structure can not be ensured, it becomes a great threat to the length of the structural life-time, and even become one of the main factors of structure failure.This paper focuses on the theoretical analysis and experimental demonstration of the prestress loss of prestressed reinforced concrete in freeze-thaw cycle, draw the prestress loss curves of different test conditions through the accumulation of a large number of experimental data and analysis,find the difference between the freeze-thaw environment and non freezing thawing environment from the drawing curve intuitively, obtain the extra loss of prestress under the freeze-thaw environment in how many percentage of the total loss of prestress, discovered trends for prestress loss. reverse proof to the feasibility and correctness of the test results by using the finite element analysis software called ABAQUS, simulated the influence of different strength of concrete to prestress, discusse the prestressed loss of prestressed concrete in freeze-thaw cycle environment, and complement the experimental results.