Shear strength and cracking mechanism of precast bridge columns with grouted sleeve connections

Precast columns are widely adopted in Accelerated Bridge Construction (ABC) due to its fast construction speed, environment amity and little interference to existing traffic. The bending behavior of precast columns with grouted sleeve connections under seismic effect has been widely studied. However, studies on the shear behavior of this kind of columns (for example, short columns under seismic effect) are limited, which restricts the application of ABC in seismic regions. This study proposes an approach for evaluating the shear cracking mechanism of sleeve region and the shear strength of precast columns with grouted sleeve connection. In this approach, the sleeve units and concrete units in the sleeve region are established according to the different stiffness between sleeve and concrete, individually. The cracking angle of membrane element of units is solved based on the Modified Compression Field Theory (MCFT). Thus, the crack developing diagram is drawn in light of the cracking range of units. An improved model for computing the shear strength of precast columns with grouted sleeve connection is presented by the predicted cracking method in this paper. A skeleton curve prediction method based on the principal compressive strain in compression zone has also been proposed and verified. In general, the improved MCFT method given in the paper is effective for predicting shear failure of precast bridge columns with sleeve connection.

Automated summary

The study proposes an approach for evaluating the shear cracking mechanism and strength of precast columns with grouted sleeve connection, using units with different stiffness to establish the structure and solve cracking angle based on the Modified Compression Field Theory (MCFT). An improved model for predicting shear strength is presented, along with a skeleton curve prediction method based on principal compressive strain in compression zone. Overall, the improved MCFT method is effective for predicting shear failure of precast bridge columns with sleeve connection.