Effects of Design‐Integrated Process Planning on Productivity in Rebar Placement

Abstract

Reinforced‐concrete structures constitute a major portion of today's construction, and placement of reinforcing bars (rebar) is an integral phase of this type of construction. Placement of rebar is an assembly‐type operation with fabricated rebar being placed and tied one by one. Process‐oriented planning for the placement of rebar aims at the creation of a placement plan that can depict the assembly sequences of individual bars, or a set or sets of bars. While complex rebar configurations necessitate that the crew foreman creates in his or her mind or on paper such a detailed plan, this traditional planning effort does not impact the delivery and staging of rebar. This paper presents a concept of rebar delivery and staging based on a placement plan and discusses the implementation of the concept in a six‐story governmental office building project in Chapel Hill, N.C. Field data on crew performance for the placement of rebar was collected utilizing three different measurement techniques: (1) Productivity ratings; (2) five‐minute rating; and (3) continuous time study. The same crew was provided with the rebar delivered and staged two ways: (1) In a traditional manner; and (2) based on the placement sequences. Finally, a comparison of the productivity results was made. It will be demonstrated where process planning was able to significantly reduce nonproductive time.