Tavern: Bendable Concrete

With increasing worldwide urbanization, the urban population has increased from 700 million in 1950 to 4.2 billion in 2018. The urban population comprises 55% of the current world’s population and is anticipated to comprise 68% of it by 2050. To support the constantly growing worldwide urbanization, the world’s concrete infrastructure systems have also experienced a rapid growth, which is reflected in the large concrete production. The amount of annual concrete production is estimated at about 12 billion tons, or about 2 tons per person worldwide per year, making concrete the second most widely consumed material by mass in the world, second only to water. Since concrete has become critical to everyday life and all fundamental human activities, its limitations have also become more and more visible.

Concrete is strong in compression but can easily crack with bending or stretching stresses. Such cracks allow water and other aggressive chemicals through the concrete cover and in turn trigger the corrosion of underneath steel reinforcement, causing both safety and durability problems.

To overcome these problems, an ultra-ductile (flexible) cement-based composite material, known as bendable concrete, has been developed. Bendable concrete looks and feels like normal concrete but exhibits an unusual tensile ductile behavior that produces cracks thinner than human hair. Such features enable the bendable concrete to undergo a described self-healing process, much like the healing from a paper cut. This talk will highlight these features of bendable concrete, together with additional properties such as high fatigue resistance, self-sensing, and self-cleaning. In addition, this talk will provide various examples to demonstrate how these properties could be translated into supporting the next generation concrete infrastructure.

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