To explore the feasibility of improving the delivery process of reinforced concrete, we focus in this paper on reinforcing bars (rebar) used in cast-in-place (CIP) concrete. Specifically, we describe the methodology for set-based design of rebar that we are pursuing in an ongoing research effort. Set-based design makes it possible to maintain feasible solutions for longer in the design process than is otherwise affordable using point-based design. It thereby allows for input from several project participants at the same time and early on, as well as throughout project delivery. Set-based communication helps participants avoid rework and through teamwork develop a more globally satisfactory design solution than would otherwise be the case. To illustrate the methodology, we examine the canonical example of reinforcement at a beam-column joint and study the relationships between those who design the joint and those who fabricate and install it: mainly the structural engineer, the fabricator, and the rebar placer. The set-based approach for concrete design is promising. It warrants further effort in characterizing sets at different levels of abstraction and in articulating what different participants value, both of which are needed for sets to be narrowed effectively and for the process to lead to a solution.
lean construction, product modelling, set-based design, reinforced concrete, rebar, design methodology, product development, design management, production system design
Parrish, K. , Wong, J. , Tommelein, I.D. & Stojadinovic, B. 2007, 'Exploration of set-based design for reinforced concrete structures' In:, Pasquire, C.L, C.L. & Tzortzopoulos, P., 15th Annual Conference of the International Group for Lean Construction. East Lansing, Michigan, USA, 18-20 Jul 2007. pp 213-222