An Experimental Study On Transmission Length And Bond-Anchorage Property For Prestressed Helical Ribbed Bar In Concrete

In this paper,the materials mechanics performance,transmission length and bond-anchorage property of the prestressed helical ribbed bar is researched using experimental methodology.In the materials mechanics performance test,the shape parameters of the prestressed helical ribbed bar are measured,the result meets the requirement of"prestressed concrete with steel bars"(GB/T5223.3-2005).The strength and elongation of the bar meets the "concrete structure design codes "(GB50010-2010).In the transmission length test,20 specimens are prepared in consideration of the main influential factors such as concrete strength,steel bar diameter and stirrup ratio.Based on the result of the test,the suggesting transmission length of the prestressed helical ribbed bar in concrete is proposed and the result of this formula agrees with that of the test.68 specimens are used in the test of the prestressed helical ribbed bar bond-anchorage property test.Influential factors which determine the bonding behavior such as concrete strength,cover thickness,steel bar diameter,anchor length and stirrup ratio are considered.Based on the result of the test,the ultimate cohesive strength formula of the prestressed helical ribbed bar is obtained using regression analysis.The result of this formula agrees with that of the test,and the steel bar anchor length meeting the reliability requirement is also obtained.Based on the results of bond-anchorage property test,the ?-s constitutive relation of the prestressed helical ribbed bar is obtained.The anchorage specimens are numerically analyzed using ANSYS,the unite COMBIN39 is used to simulate the anchorage of steel bars and concrete.The numerical results agree with the experimental results.