By 2050, over 65% of the world’s population is expected to live in urban areas, according to the C40 Cities Climate Leadership Group. Cities are the increasingly popular choice because of their proximity to city centers, schools, offices, and so on. But cities are also on the front lines of being most affected by climate change over time.

Initiatives in many major cities are working on ways to “green” urban spaces—that is, to reduce the area’s carbon footprint without taking away basic functions like transportation. Green spaces are one way to do it: in addition to making cities more beautiful, they also work to capture stormwater and reduce heat, and often the presence of green spaces encourages people to bike or walk.

Rooftop gardens are another way to make cities greener while also looking beautiful: they improve air quality, conserve energy, and help reduce the urban heat island effect as ground-level green spaces do. And engineers are making buildings more environmentally friendly by using “green infrastructure”—from porous pavements to retention ponds and bioswales.

It seems some cities have found a balance between productivity and conservation. The Italian city of Milan features the Bosco Verticale, a sustainable high-rise development that functions as a vertical forest. New York city is working on doubling the number of curbside rain gardens that efficiently absorb rainwater. And L.A.’s metro is committing to reducing their greenhouse gas emissions by 100% by 2050.
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To read more about existing green cities and suggestions for ways more cities can improve, see the full article here on the ASCE website.

Researchers at Brunel University London and Mutah University in Jordan have recently developed a way of making “stronger” concrete meant to hold up to extreme temperatures. They discovered that by adding sodium acetate to concrete mix, it renders the concrete more resistant to extremely hot or cold conditions.

Traditionally, it’s difficult to preserve concrete in cold weather because micro-cracks easily form where the water in the mixture freezes. Very hot temperatures can weaken bonds between the cement and aggregates in concrete, also leading to weakened material. By adding sodium acetate, concrete absorbs less water and increases its compressive strength, leading to stronger concrete that will require less maintenance in the long run.

Concrete has numerous uses in our field and many others: it’s an important building product, a sustainable material for residential and commercial projects, is fire resistant and easy to shape, and is typically easy to repair. By making traditional concrete stronger, the many projects that depend on concrete would benefit by becoming more stable.

To read more about the details of this research, see the article on the New Civil Engineer website.