NCHRP Project 12-74 developed and validated design methodologies, design and construction specifications, and example connection details for precast bent cap systems using emulative and hybrid connections for integral and non-integral systems for seismic regions. This was achieved through an experimental and analytical program focused on a select set of connection details. Seven bent cap to column component tests were conducted including a cast-in-place control specimen, a full ductility grouted duct specimen, one cap pocket full ductility and one limited ductility specimen, and three hybrid full ductility specimens. One girder to bent cap component test was conducted on the integral connection detail. The present project considers connections between reinforced concrete precast columns and precast footings or precast columns and precast bent caps using splice sleeve connections for seismic regions. This involves the use of steel hardware to splice the bars in-situ with high strength grout and is thus different than the connections studied in NCHRP Project 12-74. Splice sleeve connections have been studied in the past but only in the context of reinforced concrete buildings. Previous tests included connections between wall panels (both horizontal and vertical joints), and connections at beam mid-span, beam near column end, and beam-column joints.

Although the splice sleeve connection has been used in buildings, there is currently no data for use of this connection in bridges located in seismic regions. The increased use of Accelerated Bridge Construction for constructing reinforced concrete bridge bents makes the investigation of the splice sleeve connection an important topic. The project aims at performing quasi-static cyclic tests to verify the capacity of the splice sleeve connection in seismic regions for connecting precast concrete elements such as footings to columns and columns to a cap beam. Scope of Work: The project involves quasi-static cyclic testing of substructures for typical precast concrete bridge elements using splice sleeve connections that utilize large diameter bars. Primary longitudinal reinforcement for the footing, column and the bent cap will be designed based on capacity protection measures and force-transfer mechanism requirements as presented in the AASHTO Seismic Guide Specification (AASHTO 2009). Shear reinforcement near the joint region and joint shear reinforcement will be designed in accordance with the assumed force transfer mechanism of AASTHO (2009). The tasks for this project are: ¿ Tests of three precast reinforced concrete column to footing splice sleeve connections. The 8 ft long column will consist of an 18 in. square cross-section with six #8 mild steel bars. The footing will be 6 ft by 3 ft in plan and 2 ft thick. ¿ Tests of three precast reinforced concrete column to bent cap splice sleeve connections. The 5 ft long column will consist of a 18 in. square section with six #8 mild steel bars. The bent cap will be 10 ft long with a 22 in. square cross-section.

The project involves quasi-static cyclic testing of substructures for typical precast concrete bridge elements using splice sleeve connections that utilize large diameter bars. Primary longitudinal reinforcement for the footing, column and the bent cap will be designed based on capacity protection measures and force-transfer mechanism requirements as presented in the AASHTO Seismic Guide Specification (AASHTO 2009). Shear reinforcement near the joint region and joint shear reinforcement will be designed in accordance with the assumed force transfer mechanism of AASTHO (2009). The tasks for this project are: ¿ Tests of three precast reinforced concrete column to footing splice sleeve connections. The 8 ft long column will consist of an 18 in. square cross-section with six #8 mild steel bars. The footing will be 6 ft by 3 ft in plan and 2 ft thick. ¿ Tests of three precast reinforced concrete column to bent cap splice sleeve connections. The 5 ft long column will consist of a 18 in. square section with six #8 mild steel bars. The bent cap will be 10 ft long with a 22 in. square cross-section.

This project is the first phase of a larger effort to establish seismic connections for precast concrete structural elements used in Accelerated Bridge Construction. It is expected that once this first phase is complete, full-scale tests of bridge bents utilizing splice sleeve connections for large diameter bars will be carried out in the second phase.