100 year sustainable concrete developed by Australian researchers

100 year sustainable concrete developed by Australian researchers

A new type of concrete has been developed engineers at Deakin University, Australia, which is reinforced with carbon and glass fire reinforcement. The material will not need maintenance for 100 years, the researchers maintain.

As a first construction a pedestrian bridge is being built at port Campbell Creek, Victoria, which has been designed using rugged, durable materials to withstand one-in-100-year weather events.

It features open balustrading, reducing visual interference for its users as they look across the landscape. The new facilities will enhance the visitor journey with diverse experiences that are both dramatic and contemplative.

In a further significant developmenta technique for identifying cracks inside concrete by listening to how sounds spreads inside it has been developed by civil engineering researchers at Delft University of Technology in the Netherlands.

The revolutionary monitoring technique will reduce maintenance costs and help unsticking traffic on highways.

The Delft University solution is to use sound to identify subtle changes of concrete before cracking

The Delft University solution is to use sound to identify subtle changes of concrete before cracking

To collect data, engineers install optical fibres and paint slabs white, turning them into giant QR codes, to track how cracks develop on the same reinforced concrete used for bridges. “Size does matter for testing shear failures. Only 30 tests out 2,000 throughout history were done with prototypes similar to this size.”

A large percentage of Dutch highway bridges date back between 1950 and 1970. The traffic has increased in weight and frequency over the past 70 years, and regular health checks are a must to keep them secure.

Nowadays, visual inspections are the most common methods. Fixing and keeping the bridge in operation is expensive and it can hinder traffic. More in-depth methods to notice cracks beforehand can spare money and time for both engineers and drivers.

To solve such an issue, the Delft University solution is to use sound to identify subtle changes of concrete before cracking. The tracking mimics a sped up game of PONG: Smart Aggregates transmitters, two small marble pieces fitting among two fingers with an electrode in-between, emit constant vibrations and capture rebounding sound waves. Creating an inside-out virtual map of the entire structure they are applied on. If a wave from point A to point B, and the rebounding waves around, is hampered, there is a crack along the way.

By calculating the time to travel a certain distance by sound, you can determine if the material has expanded or is missing. Concrete’s granularity is excellent to spread and rebound noise waves in the whole structure.

It is proposed to surround every concrete bridge in the Netherlands with 20 euro transmitters and create a wide network monitored 24/7. The system should signal the need for intervention in time for safety purposes and disrupting traffic as little as possible.

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July 10, 2019
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