Prayagraj: Sensors embedded in concrete at the time of construction could soon help engineers continuously track its strength and detect hidden deterioration in bridges and buildings without having to break open the structure for inspection, opined experts at an international seminar at Motilal Nehru National Institute of Technology, Prayagraj.Prof KVL Subramanyam of IIT Hyderabad said special piezoelectric (PZT) sensors could be placed inside concrete during casting to monitor changes as cement sets and the concrete gains strength. The sensors record signals generated by minute changes inside the material, allowing engineers to assess the rate at which concrete is strengthening and estimate its load-bearing capacity.The technology could significantly reduce the need for destructive testing, as data from sensors embedded within concrete can provide information about the material’s condition without damaging the structure. The same principle can be used to monitor vibrations in bridges and heritage structures and assess their structural health.Associate professor Harpal Singh of Norway’s Arctic University said the technology could be particularly useful in regions exposed to extreme cold and earthquakes, where structures face additional stresses and conventional inspection can be difficult.The discussions also focused on structural health monitoring systems capable of detecting damage before cracks or visible deterioration appear. IIT Delhi professor Suresh Bhalla said continuous loading, weather variations and corrosion of steel components gradually weaken bridges and buildings, while early damage often remains invisible. Sensors can detect vibrations and minute changes and help identify weaknesses in bolted joints and concrete components.Lakshmi K of CSIR-Structural Engineering Research Centre, Chennai, said a structure could appear sound externally even after internal damage had begun. Mathematical and computer-based techniques can help locate and assess such defects, while methods such as genetic algorithms, particle swarm optimisation and differential evolution can analyse sensor data and identify damage patterns.Experts said such continuous monitoring could help authorities move from reactive repairs to preventive maintenance, extend the service life of ageing structures and reduce the risk of sudden failures and costly repairs. The three-day international seminar, organised by the civil engineering department of MNNIT, concluded on Saturday night.
