Available online at 2019.creative-construction-conference.com/proceedings/ CCC 2019 Proceedings of the Creative Construction Conference (2019) 011 Edited by: Miroslaw J. Skibniewski & Miklos Hajdu https://doi.org/10.3311/CCC2019-011 *Corresponding author: Miroslaw J. Skibniewski, email: mirek@umd.edu Creative Construction Conference 2019, CCC 2019, 29 June - 2 July 2019, Budapest, Hungary Monitoring of concrete placement and vibration for real-time quality control Sang Gyu Lee and Miroslaw J. Skibniewski a Center of Excellence in Project Management, Department of Civil and Environmental Engineering, University of Maryland, College Park, MD 20742-3201, USA, e-mail: slee239@terpmail.umd.edu Abstract This paper presents a conceptual framework for monitoring concrete placement and vibration operations. The proposed design is intended to enable collection and analysis of concrete pour data using computer vision and ultrasonic positioning. The system being developed alerts a project manager when workmanship observed is not in compliance with acceptable performance standards. The paper describes key operational factors in concrete placement and vibration that need to be monitored and reviews options for real- time locating systems. Fourteen factors related to concrete placement and their corresponding parameters are determined for measurement. In regard to the real-time locating systems, Ultra-wideband, ultrasonic, and computer vision technologies satisfy the expected levels of on-site positioning range and accuracy. Along with computer vision, ultrasonic technology has been chosen over Ultra-wideband alternative due to its lower cost and comparable performance. © 2019 The Authors. Published by Budapest University of Technology and Economics & Diamond Congress Ltd.. Peer-review under responsibility of the scientific committee of the Creative Construction Conference 2019. Keywords: concrete placement and vibration; quality control; real-time monitoring; workmanship 1. Introduction Concrete placement and vibration are vital activities that turn site workmanship into an actual concrete product. Inappropriate placement and vibration adversely affect concrete quality and cause an onset and development of a concrete defect which increase direct and indirect costs of a construction project [1, 2]. A defect not only requires time and cost to correct, but it also increases the time spent by an inspector to examine, evaluate, and document the defect. Furthermore, defects may lead a contractor to penalty fees or legal disputes. These events not only cause loss in the current project, but also reduce opportunities to win future projects by damaging the contractor’s reputation. Thus, it is necessary for contractors to reduce defects in order to save costs and secure competitiveness in the market. However, previous efforts to procure quality concrete have focused mainly on enhancing defect management practices before/after site operations (e.g. material preparation and site inspection). Current operational practices on concrete still remain to be observed and managed by human supervisors, which is not a practical solution for all-time monitoring of compliance; supervisory control is sometimes lax since all managers are busy dealing with the work progress. Moreover, such method involves inconsistent measurement and assessment in assuring conformity of rules due to different levels of knowledge, field experiences and cognitive abilities of the managers. The dynamic environment of the construction site as well as a number of ongoing tasks and labourers make it even more difficult to achieve