A Purdue University invention could save millions of taxpayer dollars and significantly reduce traffic delays. The new invention, a sensor that allows concrete to"talk", decreases construction time and how often concrete pavement（路面）needs repairs while also improving the road's sustainability and cutting its carbon footprint. Fixed directly into a concrete pour, the sensor sends engineers more precise and consistent data about the concrete's strength and need for repairs than is possible with currently used tools and methods.
"Traffic jams caused by repairs have wasted 4 billion hours and 3 billion gallons of gas, on a yearly basis. This is mainly due to insufficient knowledge and understanding of concrete's strength levels, "said Luna Lu, who has been leading development of the sensor since 2017. "For instance, we don't know when concrete will reach the right strength needed to accommodate traffic loads just after construction. The concrete may be put into use too early, leading to frequent repairing, "she added.
With the technology Lu and her team invented, engineers can directly monitor the fresh concrete and accurately measure many of its properties at once. The sensor notifies engineers via a smartphone app exactly when the pavement is strong enough to handle heavy traffic. The stronger the pavement is before being used by vehicles, the less often it will need to be repaired. By decreasing road repairs and construction timelines, this technology could reduce carbon dioxide that vehicles would have given off while waiting in traffic to get around a construction site.
Methods that the industry has used for more than a century call for testing large samples of concrete at a lab or onsite facility. Even though these tests are well understood by the industry, differences between lab and outdoor conditions can lead to inaccurate estimates of the concrete's strength due to the different concrete compositions and temperatures of the surrounding area.
