BIM-based framework for formwork planning considering potential reuse

Concrete formwork is frequently required with the increasing demands of building and infrastructure construction and has a significant impact on the costs of concrete works. Onsite formwork planning is often conducted via site managers' individual experience, resulting in low efficiency and waste production. The potential reuse and material waste reduction of concrete formwork should be focused on, and an automated and accurate planning approach is required. Therefore, this study proposes a building information modeling (BIM)- based framework to assist site managers in automatically obtaining accurate demands of concrete formwork to reduce waste and costs. The developed framework is introduced to provide an approach to information extraction, potential reuse, and waste reduction of concrete formwork and consists of three major parts: component information extraction, panel use planning, and concrete form planning. Geometry and quantity information of building concrete components is automatically extracted from a BIM model to provide more accurate quantity takeoffs compared with the conventional two-dimensional (2D) drawings. Demands of reused formwork panels are then calculated by a designed rule-based algorithm and rules based on trades' know-how. Finally, quantities of concrete forms are minimized using a 2D cutting stock problem optimization model based on the genetic algorithm. An illustrative example of a reinforced concrete building for formwork planning is analyzed using the developed framework. Results show that the developed BIM-based framework can automatically generate an accurate plan and assist to save 28% of the formwork purchase cost compared with expert-based planning methods. Furthermore, the framework has great potential for more accurate decisions making in formwork layout planning, processing, and onsite storage.