Shear Capacity of Precast Concrete Shear Keys with Ultrahigh-Performance Concrete for Connections

This paper will focus on experimental and analytical investigations into the shear capacity of precast concrete (PC) shear keys with ultrahigh-performance concrete (UHPC) as the connection (UHPC-connection PC shear keys). First, 30 shear key specimens with different configurations will be designed and tested statically under shear loads and various compressive stresses. Two major failure modes were observed during the tests, which included PC failure and UHPC connection shear-off failure, which is similar to the failure modes of conventional shear keys. Therefore, it is suitable to apply UHPC as the connection for PC shear keys. The equations to estimate the shear capacity of shear keys in the literature and current codes will be reviewed and compared with the test results. However, none of the equations accurately predicted the shear capacity of all the test specimens. Two improved analytical models will be proposed based on both observed failure modes to estimate the shear capacity of the shear keys. Satisfactory agreement was obtained for the comparison of shear capacity between the proposed analytical models and the experimental data. Therefore, the proposed analytical models could be used for the design of UHPC-connection PC shear keys. The results from this paper could guide the design of UHPC-connection PC shear keys and promote the application of UHPC materials in prefabricated structures.