Prestressed Creep Experimental Study On The Shrinkage Of Reactive Powder Concrete Beam

Reactive powder concrete(RPC)is constantly used in civil engineering buildings due to its excellent performance in various aspects.At present,there are some researches on the mix ratio,material properties and mechanical properties of reactive powder concrete.However,due to the short time of the emergence of reactive powder concrete materials,the research on reactive powder concrete materials is not comprehensive enough.For example,there is little research on the shrinkage and creep of reactive powder concrete beams,and the shrinkage and creep of concrete materials are an important part of bridge engineering design and construction.Therefore,based on the importance of shrinkage and creep of reactive powder concrete beams and the lack of research on them,this paper studies the shrinkage and creep of three reactive powder concrete beams.Based on the shrinkage and creep test data of reactive powder concrete beam,the shrinkage and creep model of reactive powder concrete beam was predicted,and the feasibility of the prediction model was verified by finite element calculation.The specific contents are as follows:(1)Further understanding of the properties of reactive powder concrete,summarizing the previous research results on reactive powder concrete,and understanding the shrinkage and creep mechanism and factors affecting shrinkage and creep,several typical shrinkage and creep models of ordinary concrete are summarized;(2)Based on previous experience,the mix proportion of reactive powder concrete was designed.Test blocks and reactive powder concrete beams were made according to the mix ratio.The material properties of these blocks were tested.At the same time,shrinkage and creep tests were carried out on reactive powder concrete beams;(3)The shrinkage and creep test data of reactive powder concrete beams were obtained.Based on the above data,the shrinkage and creep rules of reactive powder concrete beams are summarized.Based on the data of shrinkage and creep,the prediction model of shrinkage and creep of reactive powder concrete is obtained on the basis of the design code of reinforced concrete and prestressed concrete bridge and culvert in our country;(4)In this paper,the finite element model of reactive powder concrete test beam is established,and the calculated strain value and the calculated arch value of the finite element model beam with four different creep modes are calculated and compared with the measured value.Finally,the creep finite element model of reactive powder concrete beam is compared with that of ordinary concrete.