Experimental study on seismic performance of precast column with grout sleeve splicing of rebars constructed by sitting grouting method

To study the seismic performance of precast column with grout sleeve splicing of rebars constructed by sitting grouting method, eight specimens were constructed and subjected to quasi-static loading tests, and the results were compared with precast column constructed by connected cavity method and monolithic column. The failure mode, hysteresis curve, energy dissipation capacity, skeleton curve, displacement ductility and bearing capacity of the precast columns constructed by sitting grouting method were studied. The effects of connection surface process, sitting grouting construction technology and axial compression ratio on the seismic behavior of the precast columns constructed by sitting grouting method were analyzed. The test results show that the joint flexural failure occurred in the specimens with sitting grouting method, and the damage was concentrated in the joint area. The peak load, energy dissipation capacity and displacement ductility of the specimens of the sitting grouting method are similar to those of the connected cavity method specimens and the whole pouring specimens. The setting roughness has little effect on the peak load, energy dissipation capacity and displacement ductility of the specimen by sitting grouting method. Under peak load, the horizontal slip of the joint, the rotational deformation of the column, the flexural deformation of the column and the shear deformation of the column account for about 10%, 50%, 35% and 5% of the horizontal deformation of the column top, and the horizontal slip of the joint should be considered in the design. According to the test results, the calculation method of compression bending bearing capacity of joints of precast columns with sitting grouting method considering the effect of shear force, the model of joint shear-slip under compression bending shear, and the calculation method of lateral movement of the column top considering the horizontal slip of joints and the sleeve area as the rigid domain are established. The proposed loading-deflection model has taken into account a variety of influencing factors, which is close to the experimental results, and it is convenient for the structural performance design of the precast columns with sitting grouting method. It can be concluded that the process of sitting grouting method can be popularized in engineering, and the bottom of precast columns can be treated without rough surface when using sitting grouting method. © 2023 Science Press. All rights reserved.