As-Built Documentation of Structural Components for Reinforced Concrete Construction Quality Control with 3D Laser Scanning

Abstract

As-built BIM is a relatively new concept to the AEC/FM industry and has not been applied to many project elements yet, including structural components. The conventional methods of as-built documentation of structural components, such as rebar cage, do not provide sufficient information and often lead to rework and project delay. A comprehensive dimensional quality control of installation of structural rebar and anchor bolts is very time-consuming and labor intensive with traditional surveying systems. It is impractical to check every rebar and anchor bolt within the structure with sparse data collection. However, laser scanning is capable of bridging this gap by providing dense point cloud data of such components at construction site. This paper introduces the use cases of scanning structural rebar in reinforced concrete construction. A successful experiment of scanning structural rebar was conducted in a construction project. As-built conditions of rebar cages and anchor bolts were documented in BIM environment and compared against as-planned model. The result of the comparison and the benefits to the contractor are explained in the paper.