Construction management automation technology useful for ensuring quality

The total concrete volume acceptance management system using video analysis obtains the gradient of concrete that flows through the chute of agitator truck through video analysis and estimates slumps based on new criterion calculated from the gradient in real-time to automatically eliminate concrete with low workability, so-called rigid concrete.

Usually, the concrete acceptance inspection is a sampling inspection as often as once every 20 to 150 m3 segments. Therefore, rigid concrete with small slump may be overlooked if these are not subject to inspection. If such concrete is casted, it causes problems such as clogging of piping or filling failures, resulting in significant degradation of structural quality.

Therefore, we started the development of this system by automatically identifying rigid concrete with small slump. First, we visualized the movement of concrete going down through the chute based on which experienced engineers precisely estimate slumps by using an eye tracking device that captures the movement of human eyeballs and calculates their observations. The results revealed that these engineers estimate the rigidity of concrete based on the gradient of concrete flowing through the chute, and that more rigid concrete is thick and flows down slowly. Based on these facts, we invented a method to identify this characteristic through video analysis.

This system consists of a video camera, a PC to determine material properties, and a rotary beacon light. This system allows acceptance management and inspection of the total concrete volume delivered without having to allocate monitoring staff on site. In addition, this system can transfer video data to manage monitoring in the office or to conduct concrete acceptance inspections from remote locations. The system can also save manpower while ensuring structural quality.

Kajima is dedicated to analyzing data obtained using ICT and sensing technology that replaces the five senses of experienced engineers who reliably manage construction and to applying analysis results to the PDCA cycle of construction management to improve productivity through labor and manpower saving while maintaining quality.