Tech-driven approach to building inspection, maintenance, and repair

The partial collapse of a commercial building, a girder falling at a construction site, a plaster peeling from the ceiling of a house, a crashing façade, and a falling brick are all signs of poor construction or lack of maintenance. Disasters do not happen in a single day! What often starts as a small crack can amplify into significant issues over time. While structures may be aesthetically pleasing when constructed, it is also important that they stand strong for decades. Preservation of structural integrity goes beyond the construction phase. Whether it is our homes, business centres, or heritage structures, proactive maintenance is crucial. However, can proactive maintenance be achieved solely through the visual examination of the structure?  Let’s discuss it!

What you can’t see can be more dangerous than what is visible to your eye! This is where technology comes into play! Thankfully, advancements in technology have made the task of building inspection easier, faster, and more reliable.

In an online interaction organised by ACE Update, acclaimed industry experts share their expert insights on how technology is reshaping building inspection, maintenance, and repair, ensuring a safer future for both buildings and their owners.

Why is structural health monitoring (SHM) important?
In India, residential structures outnumber commercial structures, making the evaluation of SHM critical. This is because quality is often overlooked in residential construction, as financial aspects take precedence. Lack of education among homeowners is also a reason. Dr S.V. Chandramouli, Consultant – Structural Engineering | SHM | ART, explains why condition monitoring of structures is essential. “We often compromise on quality for price. To determine whether this is impacting the structure, a monitoring system is necessary. Also, in India, SHM specifically for structural vibrations is not widely implemented because small residential buildings are less susceptible to damage compared to high rises.”, asserts Chandramouli.

How autonomous drones and AI are changing the game?
Drones are not only enabling fully automated remote inspection workflows but also improving operational health and safety. Drones can be especially useful in the case of high rises; e.g., while a cycle of inspection might take almost a year using traditional methods for an 80-storeyed building, a drone can scan the whole building in 2 weeks. Dr Dhanada Mishra, Managing Director of RaSpect Intelligence Inspection, explains how AI is a great enabling technology for handling huge volumes of data. “A drone can scan a whole building in 2 weeks at most. However, the entire dataset can be humongous to process manually. This is where AI helps! You put all this data through AI to know which photo belongs to which floor, elevation, and the defect detected.,” comments Dhanada.

Aspects related to accessibility, such as height, scale, and confined spaces also pose severe challenges to physical inspection. Drone-based visual and thermal inspections are effectively addressing such challenges, common in high rises. Dr Balaji Singh, CEO & Founder, BPT Group of Companies, explains how advanced drone-based technologies are pioneering this. “This is where drone-based visual and thermal inspections come into play. High-resolution thermal cameras provide excellent results and ensure nothing is missed. Robotic crawlers are used in ducts and shafts to reach places where the naked eye cannot go, nor can be manually inspected. “, comments Balaji.

Defect analysis of substructures
Substructure inspection is often overlooked due to the difficulty in accessing. But, substructures’ role is critical for ensuring the structural integrity. Dhanada offers insights on how monitoring superstructures also can provide a cue to substructure health. “Dynamic structural behaviour monitoring of the superstructure can offer indirect clues about issues like subsidence or foundation problems. Since substructures are not accessible for direct visual inspection, we often rely on how the superstructure behaves—tilting or abnormal movements—to infer underlying issues.”, opines Dhanada. “But, unless sensors are pre-embedded in the substructure, getting direct GPR data is difficult.”, comments Dhanada.

Adding to this, Balaji opines why working on substructures without historical data is challenging … “When it comes to substructures, historical data is extremely important. We cannot generalise because “substructure” itself is a broad term. It must be divided into different zones, and within each zone, specific elements involved must be identified. Is the issue related to rebars? Concrete? Leakage? Settlement, etc.?”

Chandramouli also concurs with the observation. “The superstructure should aid us in indirectly analysing what’s happening below. Essentially, this is geotechnical investigation, where GPR and wave-based testing techniques, including shear wave and seismic wave testing, are extensively used. Embedded sensors and continuous rebars in place can help assess the extent of damage.”, asserts Chandramouli.

How microwave inspections are transforming NDT?
Dhanada exemplifies how microwave inspections facilitate the precise identification of issues, particularly those related to water ingress. “With microwave scanning, we can now actually have a 3D view of how the moisture spreads through the structure. This insight leads to more accurate and effective repairs.”, asserts Dhanada.

How technology is accelerating repairs?
Digital twins are gaining momentum in targeted repair. “From a lifecycle maintenance perspective, all available information about the structure can be collected, and digital twins make the information easy to visualise. When integrated with BIM, it becomes easier to collect historical data and continuously add inspection and maintenance records to it.”, shares Dhanada.

Today, VR/AR allowing for remote consultations and providing real-time guidance to technicians. Chandramouli explains how this is gaining momentum in India. “While it does provide an immersive experience, especially in understanding drawings, the industry is still largely working off physical plans. VR is mainly being used in the construction phase. Once the model is created in BIM, VR/AR is applied on-site to visualise the design.”, opines Chandramouli.

The future of tech-driven inspections
While technology has already taken its place in building inspections, further advancements and integrated approaches are sure to redefine SHM. Experts agree that, over time, SHM systems, such as strain and accelerometer monitoring, will become integral to smart systems. Similarly, in future, cameras could be used to monitor cracks in buildings, and accelerometers and strain gauges may also be integrated to provide additional information. Fixed cameras with high-frequency imaging or video technology are also emerging, which can act as substitutes for traditional accelerometers or other types of sensors mounted on structures