| Since entering the 21 st century,the concept of sustaninable development and rational consideration has been developed around the word,as a new type of development stratregies and models have been universally recognized green building is currently promoted in China,the essence is to achieve the sustaninable development of construction industry.With the vigorous development of the national economy,people`s living standard is improving,at the same time,people`s comfort level,spece and shape structure of the building has the higher request,in order to satisfy the demands of people`s life and work.Prestressed concrete structure is famous for its big span,save building materials,improve the construction and structural features of such outstanding advantages,to meet the modern building structure,prestressed concrete structure can give full play to material properties,improve the crack resistance,stiffness and durability.The high-strength steel and high grade of concrete can be used effectively.Compared with ordinary concrete structure,it not only has the components of small sedtion,light weight,favorable quality,material saving but also sxpands the degree of predtress assembly.Steel strand is one of the most widely used material in the prestressed structure,which is developing in the direction of high strength,low relaxation,large diameter and corroison protection.At present,a large number of experiments and theoretical studies have been done on the mechanical behavior of prestressed concrete members with conventional diameter steel strand(diameter 15.2mm)and high stength non-prestressed steel bars,but for the configuration of large-diameter high-strength steel strand of prestressed concrete members related to the force performance still less,for this research gap,the mechanical behavior of prestressed concrete members with large-diameter high-strength steel strand were studied,which provides a reference for the application of large-diameter high-strength steel strand in practical engineering.In order to research the mechanical behavior of prestressed concrete members largediameter high-strength steel strand,the reinforcement radio and the span ratio of nonprestressed steel bar are taken as the characteristic parametes,six prestressed concrete beam specimens with large-diameter high-strength steel strand are prepared and analyzed.The results show that: the failure mode of predtressed concrete beams with large-diameter high-strength steel strand is similar to ordinary concrete beams,they all exprerience elastic stage,working with cracks stage and failure stage;The flexural capacity of prestressed beams with largediameter high-strength steel strand is direct proportion to that of non-prestressed tendons,and is inversely proportional to span-to-height radio;The applicability of the Code for Design of Concrete Structures(GB50010-2010)to calculation of flexural bearing capacity,stiffness and maximum crack width of large-diameter high-strength steel strand prestressed concrete beam is verified.The results show that: the flecural capacity,stiffness and maximum crack width of the prestressed concrete beams with large-diameter high-strength steel strand that is calculated according to current specification is well with the measured value.Based on the experimental data,The ABAQUS finite element software was used to simulate the normal section of the six test beams.The ultimate bearing capacity,the mid-span deflection analysis and the compressive stress cloud were obtained and compared with the experimental data,and the simulation result is well sgreed with the measured value. |
