Study On Properties Of Rebar With Steel Sleeve-Bolt-Structural Adhesive

One of the technical difficulties in reinforced concrete prefabricated buildings is to ensure the strength and stability of the steel joints between the prefabricated components.At present,there are two types of steel joints that are commonly used in assembly engineering: sleeve grouting connection method,constraint Slurry anchor connection method.However,in the casing grouting connection,the curing of the grouting material is an important step to ensure the joint strength of the joint,which is greatly affected by the environmental constraints.Under the action of force,an unfavorable additional bending moment effect is generated,because the pulling force acts on the two steel bars which are not on the same axis,thereby weakening the bearing capacity of the steel connecting member.Therefore,this test is to design a new type of steel bar that is easy to construct and has good mechanical properties.The steel sleeve-bolt-structural rubber mixed connection steel bar joint is designed to ensure the "equal strength principle".The strength of the joint is not weaker than the tensile strength of the steel itself.In order to study the influence of the length of the sleeve and the amount of bolt on the ultimate tensile capacity of the joint,three sets of sleeves with lengths of 150 mm,210mm and 250 mm and three sets of bolts of 0,4 and 8 bolts were designed.24 steel connecting members.Through the single-row tensile test,the ultimate bearing capacity of each member and the relative measured displacement of the steel bar are obtained.Combined with the failure phenomenon of the steel connecting member under the maximum bearing capacity,the tensile strength and the ultimate bearing capacity of the member are discussed Impact.After analyzing the data and combining the finite element numerical simulation,the following conclusions can be drawn: the joint connection of the 210 mm and 250 mm sleeves under the condition of 8 bolt clamping meets the requirements of the specification for the tensile properties and deformation properties of the III joint.The measured tensile strengths of the joints are 85.48 kN and 90.05 kN,respectively,which are greater than 1.25 times of the measured yield strength of the steel base metal test,is 83.51 kN;the measured residual deformation of the joint is 0.094 mm and 0.087 mm,respectively,which are less than 0.1mm of the specification;the measured tensile strength of the steel bar is 12.18% and 11.56%,respectively,which also meets the requirements.Through the comparative analysis of 8 sets of test pieces,the formula of the bearing capacity of the test piece of “steel sleeve-bolt-structure adhesive ” mixed connection rebar was fitted.Figure 76;Table 26;Reference 56...