Reinforced concrete is used in capital facilities in all sectors of the construction industry. Numerous specialists are involved in its design and supply chain. However, reinforcing steel (rebar) configurations are typically specified by structural engineers relatively early on in the project, often without the benefit of input from project stakeholders such as rebar detailers, fabricators, and placers. In current design practice, using tacit knowledge of structural performance as well as construction expertise, structural engineers select a rebar configuration that is optimal from their perspective, given the project constraints. The adoption of new design methodologies, such as performance-based design and set-based design, affords opportunities for use of the knowledge of downstream project stakeholders in structural design. Value propositions relate, e.g., physical product characteristics, relative dollar, or time ‘costs’ to parameters that define value for different project stakeholders. They can then be used to assist project teams in developing mutual understanding while gauging the merits of different sets of alternatives, making tradeoffs, and narrowing sets of design alternatives. Industry participants in this research have helped to develop such value propositions. This paper presents a value proposition of a rebar placer, that relates rebar diameters to labour productivity rates, and these can be translated into placement costs. Proof-of-concept is delivered of the use of this value proposition in set-based design of a reinforced concrete shear wall.
lean construction, set-based design, performance-based design, reinforced concrete, rebar, design methodology, value proposition, stakeholder value, constructability, cost
Parrish, K. , Wong, J. , Tommelein, I.D. & Stojadinovic, B. 2008, 'Value Propositions for Set-Based Design of Reinforced Concrete Structures' In:, Tzortzopoulos, P. & Kagioglou, M., 16th Annual Conference of the International Group for Lean Construction. Manchester, UK, 16-18 Jul 2008. pp 495-506