Connections for the Assembled Monolithic Frame Consisting of Confined RC Columns and Composite Beams and Its Construction Technology

Abstract

High strength concrete under compression has poor ductility, which limits the engineering application of high strength concrete columns. To achieve integrity and seismic resistance, more concrete is cast in the construction of the assembled monolithic frame, which means more wet operations. Temporary bracing is necessary to maintain the stability of a precast structure during construction. Too many wet operations and too much temporary bracing reduce the speed of construction and increase the construction costs. To solve above problems, In accordance with the 500 000 m2 project of the assembled monolithic frame consisting of confined RC columns and composite beams, the construction technology of the high strength compound spirals, the
connection for the precast component, and the construction technology of the frame are studied. The construction practice of the 500 000 m2 project shows that: (1) the construction speed of the high strength compound spirals is twice that of the single tie; (2) with respect to low strength ties, half of the amount of reinforcements can be saved in the engineering application of high strength spirals; (3) The precast component’s connection provided in this paper can achieve integrity and seismic resistance under the condition of less wet operations; and (4) the construction technology of the assembled monolithic frame provided in this paper does not require temporary bracing; in addition, it not only meets quality demands but also speeds up the construction. The 500 000 m2 project lasted for eight months. It was completed 10 months ahead of schedule unlike the cast in place frame. The early completion brought good economic benefits to the investors.