Connection Performance Of Bar With Bolt Anchor In Precast Grout Holes

With the rapid development of bridge construction,the rapid construction of bridges has become the development direction and current research focus of bridge construction.The rapid prefabrication and assembly technology of bridges has been successfully applied in the current bridge construction due to its short working time,high construction efficiency,and low impact on the surrounding environment.In the rapid prefabrication and assembly technology of bridges,the connection performance and reliability of each prefabricated component have become a key issue in the bridge prefabrication and assembly technology.So “the Connection of Bar with Bolt Anchor in Precast Grout Holes” is proposed with a simple connection process,fast construction speed,and high reliability,consisting of precast grouting holes,connecting steel bars,bolt anchors,and high-performance grouting materials in this paper.The theoretical analysis and experimental study were carried out and the corresponding minimum anchorage length calculation formula was proposed.The main research results are as follows:(1)By referring to the relevant design manual,considering the practical application of the project and referring to the design specifications of the relevant mechanical anchorage and the specific size requirements of the bridge piers,a bolt anchor head for the connection of precast grouted hole is designed and the parameters of an anchor head is obtained including inside and outside diameter,internal and external threads,pitch and material.(2)According to the three failure modes of the connection of bar with bolt anchor in precast grout holes,namely the tensile failure of reinforced bars,the cone failure of concrete,and the pull-out failure of reinforced bars,the calculation methods for the minimum steel anchors lengths of three kinds of were deduced respectively.The calculation formula of the minimum steel anchorage length of the precast grouted hole connection is calculated,and the calculation shows that the minimum steel anchorage length is 6.5d.(3)Sixteen test specimens were prepared using the connection of precast grouting hole,and the pullout test was conducted to obtain the failure modes and the load-displacement curve of the components using this new connection method,which was used to analyze the anchorage performance of the connection.When the anchorage performance of the head connection is less than 6d,the cone failure of the connection mode occurs,which verifies the correctness of the calculation formula of the minimum anchorage length proposed in this paper.The connection of bar with bolt anchor in precast grout holes proposed in this paper has theoretical significance and application value for rapid construction of prefabricated and assembled bridges.