Responsive Structures

As a proud and unabashed geek, the marriage of computer technology to my chosen field of profession is of particular interest to me. In an article I read recently from Science Daily, “Sensor Sensibility: Better Protection for Concrete Coastal Structures” they introduce a technology that will open the door for a whole new generation of civil engineering.

The article talks about a new sensor technology that can be deployed long-term, semi-permanently into concrete structures to monitor such metrics as pH and chloride levels.  The real news here is not the sensor, those have been around for some time. Instead the real hero here is the extended lifespan. The new sensor has an estimated lifespan of several years, up from just weeks due to the harsh chemical environment found in concrete. This extended lifespan makes practical real-world applications of concrete monitoring a reality.

This is particularly important for the applications of steel reinforced concrete, for example, in a road.  Concrete itself is not susceptible to water corrosion; however, the steel rebar within it is very much so susceptible to oxidation or rust.  This is particularly important in roadways where the use of salt in ice abatement is common practice. Salt and water both will permeate the concrete and reach the steel within. Sensors like these will provide maintenance managers and engineers warning of a decaying structure before it fails instead of waiting for the tell tale sign of cracked concrete and exposed steel reinforcing to make costly repairs.

Although the sensor and the implication of early warning information are both important technological advances, the true future of this technology, the way I see it reaches out much, much farther.

Enter – the integrated world.  Yes, I used a buzzword, but in this case it is actually the correct one. In my opinion the future of almost every field is simply this: integration. The sensors mentioned in this article combined with others such as extensometers, capable of measuring strain on structural members can be combined.

Communication technology has come far enough now that is reasonable to expect devices to communicate effectively between each other. I believe the future of construction, and therefore structural engineering, is in responsive structures.

I define a responsive structure as one that is integrated by a computer system such that it is capable of responding to conditions intelligently.

 Imagine for a moment a busy downtown bridge fitted with strain, corrosion and load sensors. On some random, so –far uneventful day a computer integrated with the bridge’s sensors and a database of historical traffic data determines that: at current corrosion levels of a specific structural member, combined with expected rush-hour traffic that the bridge will likely exceed its safe structural operating threshold. The computer responds by automatically closing the bridge, working in tandem with the systems operating city street lights to re-route traffic while at the same time notifying the necessary people regarding the situation.

These sensors bring us one step closer.