A BIM-Based Bar Bending Schedule Generation Algorithm with Enhanced Accuracy

Abstract

Rebar quantity estimation is pivotal for determining the cost of construction projects and is essential for bidding purposes. A bar bending schedule plays a crucial role by providing rebar information and bending instructions, facilitating efficient procurement. Traditional methods, which rely on manually extracting data from 2D (two-dimensional) drawings, are error-prone and hinder construction productivity. This study utilized a special length approach to yield optimal rebar consumption, resulting in a total rebar order of 19,582.427 t and minimizing rebar waste to 0.77%. Additionally, this method saved 3000.22 t of rebar compared to traditional methods, using only stock lengths. To enhance the accuracy and efficiency, a 3D (three-dimensional) model was developed in a Building Information Modeling (BIM) environment to prepare a Bar Bending Schedule (BBS) automatically, integrated with an Application Programming Interface (API) for data entry to eliminate manual errors. The efficacy of the proposed algorithm was confirmed by comparing the rebar quantities it generated with those obtained from optimization calculations. The results demonstrated a mean absolute error of 0.017 and a mean absolute percentage error of 1.13%, validating the algorithm’s precision. Furthermore, this method reduced the manpower required for BBS preparation by 33.33%, highlighting its potential to revolutionize construction workflow efficiency and accuracy.