Prof. Dr. Bernhard Elsener, ETH Zurich, Institute for Building Materials argues that civil engineering should embrace the Internet of Things and its values to ensure our future structures…
Reinforced and pre-stressed concrete is, and will be, the main construction material for civil engineering infrastructure – bridges crossing valleys, tunnels under mountains, high skyscrapers – but also the less spectacular infrastructure for water and energy essential for society.
The civil engineering industry is currently, in many industrialised countries, in a transition phase from building new constructions to maintaining the large stock of valuable assets. These reinforced concrete structures are aging and very often show premature deterioration due to corrosion of the reinforcement, with increasing costs for maintenance and repair.
Taking into account that the average lifetime of a repair is shorter than that of the original, a dramatic increase in the number of structures that have to be repaired and the associated costs, can now be predicted. This prediction however, does not include indirect costs such as energy consumption, pollution, traffic jams etc. that are equally relevant for society.
Today, engineers and owners try to extend the service life of these assets with a minimum of interventions, with sophisticated management systems – maybe with more effective and durable repair methods – but a new approach is lacking. Life-cycle thinking is urgently needed for education and the continuous formation of professionals, for both stakeholders and society.
Why for instance, is a car carefully designed for easy inspection, containing a wealth of monitoring systems which gives an alert when a repair is needed, but a much more expensive civil engineering structure with expected service life of 100 years is not? The new megatrend, the Internet of Things where the installation of cheap, wireless sensor networks with intelligent software and local computing power, could be used for health monitoring of structures. Vibrations, deformations, change in concrete humidity and chloride content, the corrosion-state of the reinforcement can all be measured. What is needed is software that, out of this huge amount of data, creates practical and useful information for owners and engineers for every single structure. This is not only a great field of research, but will allow in the future a benchmark between different structures, contractors, regions and countries. Everybody, including the stakeholders, could observe in real-time who is doing better.
The needs of a changing society present new challenges for civil engineers, like how to reduce our environmental impact, and the preservation of ageing infrastructure. The traditional way of construction, the known technologies, might not succeed. What we need is a paradigm change towards new technologies. Here academics and practitioners, owners and stakeholders need to take a step forward. â–
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Prof. Dr. Bernhard Elsener
Head Durability Research Group,
Institute for Building Materials
ETH Zurich
Tel: +41 44 633 2791
elsener@ethz.ch
