Synthesizing engineering design, material takeoff and simulation-based estimating on a bridge deck reinforcement case

摘要

To enhance the accuracy in estimating material and crew costs for steel reinforcement installation, numerous estimating tools have been developed. “Precise estimating” in general considers both lapping details and other required supporting structures while deriving the crew cost by accounting for reinforcing operations. In contrast, “rough estimating” ignores rebar lapping details in quantity takeoff and relies on industry benchmark productivity data for crew cost estimation. The distinction between “precise estimating” and “rough estimating” still lacks quantitative evidence and remains vague to both academic researchers and professional estimators. This research presents systematic comparison between the two estimating strategies with a case study of a bridge deck. A discrete event simulation tool is used to aid in estimating the crew cost in reinforcement handling and installation. The estimating results indicate that compared with the “precise estimating” approach, the “rough estimating” approach underestimates the material and crew costs by 13% and 38%, respectively.