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This paper presents the results of experimental investigations on four full-scale precast concrete connections and a half-scale, two-story, two-bay, precast concrete, moment-resisting frame, which consisted of composite concrete beams and cast-in-place concrete columns, under cyclic loading. The precast concrete connections investigated in this paper included an exterior connection, an interior connection, a T connection, and a knee connection. Test results revealed that the four precast concrete connections, as expected, exhibited a strong column-weak beam failure mechanism and failed due to concrete crushing and fracturing of longitudinal bars as a result of forming a plastic hinge at the fixed end of the beam. The four connections behaved in a ductile manner. However, the displacement ductility of the knee connection was the poorest among them. The precast concrete frame exhibited a mixed side-sway mechanism and behaved in a ductile manner. The hysteresis curves of the frame were full and exhibited good energy-dissipation capacity. The global and interstory displacement ductility of the frame was not less than 4.5. In general, the seismic behavior of the precast concrete frame was satisfactory. This research could provide structural engineers with useful information about the safety of precast concrete-frame structures. [ABSTRACT FROM AUTHOR]

The article focuses on the sophisticated design of the prestressed and precast concrete hollow-core beams used for interchange bridge project in San Pedro Sula, Honduras. It mentions that the designer must concentrate on the ease of fabrications, repetition, and ease of assembly to make a cost-effective solution using precast concrete. It presents several photographs and illustrations of the designs of the prestressed and precast concrete hollow-core beams used in the interchange bridge project.

Erection of long, vertical precast concrete members from their as-delivered horizontal position to their vertical position in the structure involves devising handling procedures that protect the safety of the erection personnel while preventing the precast concrete member from cracking during the tilting procedure. The author investigates the most commonly used procedures, three-point and four-point rolling-block lifting systems, and identifies a common instability condition that causes sudden, uncontrolled rolling of the members as they are being tilted toward their vertical position. Methods are devised to detect in any member the potential for such instability, to establish safe location of lifting devices and minimum lengths of crane slings to prevent this condition from occurring, and to analyze and control tensile stresses from causing cracking of long precast concrete wall panels as they are lifted from their horizontal position, rigged for the tilting operation. [ABSTRACT FROM AUTHOR]

The article announces the call for the precast/ prestressed applications for innovative formwork and equipment solutions to join the 47th annual Design Awards Competition for 2009.