PLACEMENT-ORIENTED DESIGN AND DELIVERY OF CONCRETE REINFORCEMENT

The use of reinforced concrete in the United States is steadily increasing, and with it the need for designed and fabricated reinforcing bars (rebar). Traditionally, the detailing of the rebar is done by the fabricator, who is required to have the shop drawings approved by the civil engineer in charge of the structural design. Subsequently, the rebar is fabricated and shipped to the site where an independent subcontractor places the rebar according to the detail design. Research has shown that the delivery of construction material is strongly related to the productivity of construction processes, such as laying rebar. However, traditional rebar fabrication and shipment is geared towards minimizing the set-up time of the rebar bending machine. As a result, rebar is cut, bent, and bundled according to shape and size without considering the sequence of placing the bars. This paper presents an alternative way to design and deliver concrete reinforcement that is based on computer integration and feature-based design concept. Detailing data generated with CAD software is used to create rebar placement plans, shipping schedules, and assignments of lay-down area on the construction site. Based on experiences with the application of the system, steps necessary for its implementation are discussed.