This Robot Finds Cracks and Fixes Them

On a high-rise or an inaccessible facade, locating and mending defects is no easy matter. It typically means putting workers at height with the aid of scaffolding and other specialized gear. Yet even a seemingly minor crack can be an entry point for moisture which, over time, will corrode the structure and cause it to deteriorate. 

That’s where this robot comes in. Researchers at Southeast University in Nanjing, China, through its School of Civil Engineering and the Key Laboratory of Concrete and Prestressed Concrete Structures of the Ministry of Education have developed a wall-climbing robot that combines inspection and repair in one system. It detects cracks, measures them and seals them up without the need for a separate crew. 

The Mechanics of the Robot 

Negative-pressure adhesion allows the robot to scale vertical concrete walls, while its onboard vision system, powered by a lightweight AI model, maps the width and shape of any cracks it encounters. From that data, the robot plots a course for the sealing mechanism and makes the necessary repairs. This approach reduces the number of steps involved in traditional concrete maintenance.  

Results of the Tests 

The numbers from full-scale trials on a wall are promising: 98.6 per cent average coverage for repairs and an underfill of only 1.4 per cent. The tests also turned up relative errors of 0.53 and 1.49 per cent in measuring crack width. For something that is supposed to detect and remedy damage in one go, that is encouraging.  

Zhenqin Huang, Kang Gao, Shuyi He, Dandan Gu and Zida Chen present their findings in the August 2026 issue of Automation in Construction. 

Is This the Future of Concrete Maintenance? 

With inspection and repairs handled by a single robot, concrete maintenance could become safer, faster, and more efficient. This means less time setting up equipment and fewer workers having to work at dangerous heights. 

However, controlled experiments don’t always reflect real-world conditions, where uneven surfaces and complex crack patterns can pose challenges. More testing is needed to gauge the system’s practical utility. 

In the meantime, Huang and his colleagues’ work shows that wall-climbing robots could move beyond inspection and play a role in maintaining concrete structures.