Automated Geometric Quality Inspection of Rebar Layout using RGBD Data

Quality control and quality assurance during construction is vital to ensure the structure is built as designed and durable. For reinforced concrete (RC) structures, rebar diameter, spacing, and concrete cover depth are critical in ensuring that the structure is designed for adequate strength and can maintain its service life without unplanned interventions. Once the rebar is laid out in the field, construction inspectors do the required quality control to ensure that the constructed rebar mat matches the design documents. The checks are made at finite points and thus can be improved with currently available technologies such as LiDAR, augmented reality (AR), and uncrewed aerial vehicles (UAVs). This paper summarizes the available technologies for such an effort and focuses on using Red Blue Green Depth (RGBD) cameras as a quality control tool for construction inspection of RC structures such as buildings and bridges. A study conducted using an RGBD camera for estimating rebar diameter is presented in this paper. Results show that RGBD cameras have a very high potential as a low-cost, efficient tool for quality control of RC structures during construction. RGBD cameras can potentially augment current visual inspections in assuring the structures are built as per design drawings, meeting the appropriate specifications with acceptable accuracy.