Experimental study on the pull-out performance of new composite dowels in steel-UHPC structures

In order to study the pullout performance of a new type of steel-UHPC composite dowel connector, based on the actual engineering background, two groups of 16 composite dowel connector pullout tests were designed. One group had studs welded on the steel pins, and the other group did not. During welding, composite dowel connectors with different heights and different inclination angles are set up for pullout performance testing. According to the test stress mode, ABAQUS implicit analysis was used to simulate and analyze the drawing process of the specimen. Finally, combined with the test data and finite element analysis results, the limit drawing of a single steel pin and multiple steel pins in UHPC was proposed. Bearing capacity calculation formula. The test and finite element analysis results show that the initial failure modes of Type 2 shear connector specimens are UHPC failure; the stiffness and load-bearing capacity of steel pin-bolt connectors during the drawing process are higher than those of pure steel pin connectors. After adding the studs, the tensile bearing capacity of the specimen can be increased by about 49% to 84%; increasing the effective embedding depth of the steel pins and UHPC tensile strength and supporting volume can increase the resistance of the new composite dowel connectors. Pull out the ultimate bearing capacity.