maintenance costs

Self-healing concrete

June 25, 2025 By EarthWise Leave a Comment

Concrete is the most widely used building material on Earth. It has a dangerous and costly flaw: it cracks easily. Cracks in concrete can lead to inconvenient damage or to catastrophic structural failures such as collapses of buildings, bridges, or highways.

Concrete is made by mixing crushed stone and sand with powdered clay and limestone and adding water. The mixture hardens and once set becomes extremely strong. However, natural forces like freeze-thaw cycles, drying shrinkage, and heavy loads can cause cracks. Even very tiny cracks can allow liquids and gases to seep into embedded steel reinforcements causing corrosion and weakness.

For over 30 years, researchers have investigated microbe-mediated self-healing concrete. It involves introducing microbial healing agents into cracks and injecting nutrients for the healing agents to produce repair materials. It is not a very practical solution.

Researchers at Texas A&M University have developed a technique inspired by the behavior of lichen systems. Their system, like lichen, uses a combination of cyanobacteria which turns air and sunlight into food, and filamentous fungi, which produces minerals that seal the cracks.

In lab tests, the paired microbes were able to grow and produce crack-filling minerals even in challenging environments such as concrete. If it is possible to produce concrete that can heal itself, it would significantly reduce maintenance costs, extend its longevity, and even protect lives through increased safety.

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Cracking the Code: Deciphering How Concrete Can Heal Itself

Photo, posted May 21, 2009, courtesy of DesignMag via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Explosive Growth Of Electric Vehicles | Earth Wise

May 25, 2023 By EarthWise Leave a Comment

Not long ago, electric cars were a rarity. Ten years ago, annual global sales of EVs were only a few hundred thousand. As of today, globally, still less than one percent of all the cars on the road are electric. But that is changing rapidly.

In fact, electric vehicles are expected to capture nearly 20% of the global market this year. Global sales of EVs were 3 million in 2020 and 6.6 million in 2021. Last year, sales of electric vehicles hit 10 million and are expected to reach 14 million this year according to the International Energy Agency.

Analysts at the IEA have had to repeatedly revise their projections for future EV sales as the numbers keep going up faster than predicted. Last year, they projected that EVs would account for 21% of global sales by 2030. Now, they expect that EVs will reach 35% of sales by that year.

In the US, the EU, and China, policy efforts are in place to boost EV sales. In the US, the Inflation Reduction Act both supports the EV industry and subsidizes consumer purchases with tax credits. As a result of such policies, the IEA expects electric vehicles to account for 60% of sales across these three large markets by 2030.

Part of what is driving the boom in EV sales is that prices continue to come down for the vehicles. When operating and maintenance costs are figured in, the EVs come out considerably cheaper to own. In addition, there are starting to be price wars in the EV industry as competition heats up in the sector.

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EVs to Capture One-Fifth of Global Market This Year Amid ‘Explosive Growth’

Photo, posted May 7, 2022, courtesy of Sharon Hahn Darlin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Driving Electric Is Cheaper For Almost Everyone | Earth Wise

February 24, 2023 By EarthWise Leave a Comment

A study by University of Michigan researchers found that about 90% of U.S. households would save money on fuel costs by owning an electric car rather than a gas-powered car. So apart from the environmental benefits of electric cars, there are real economic benefits as well.

Both the price of gasoline and the price of electricity vary considerably across the country, so there are differences by location. The study found that 71% of U.S. drivers would see their fuel expenses cut at least in half by driving an electric car.

Drivers in California, Washington, and New York would see the largest fuel savings as well as the biggest emissions reductions from a new electric car. Those states have cleaner electric grids and a bigger gap between the cost of electricity and the cost of gas.

The study, published in the journal Environmental Research Letters, only looked at fuel costs and did not take into account the purchase cost of new cars. Generally speaking, plug-in cars have higher sticker prices than gas-powered cars but multiple studies have shown that over their lifetimes, electric vehicles end up being cheaper to own than comparable gas-powered vehicles because of lower maintenance costs on top of the fuel savings. The price gap between equivalent gas and electric cars continues to narrow in any case as the cost of batteries continues to decline. On top of that, the recent expansion of federal tax credits on electric cars is making the vehicles cost-competitive right at the point of purchase.

Gasoline prices have come down considerably from their peak a year ago, but for almost everyone, it is still much cheaper to drive on electricity.

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Seven in 10 U.S. Drivers Could Halve Their Fuel Costs by Going Electric, Study Finds

Photo, posted April 23, 2022, courtesy of Pedrik via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electrifying The Federal Fleet | Earth Wise

October 7, 2021 By EarthWise Leave a Comment

The federal government owns and operates about 645,000 vehicles. Among them are about 200,000 passenger vehicles, 78,000 heavy-duty trucks, 47,000 vans, 847 ambulances, and three limousines. About 225,000 vehicles are operated by the Postal Service.

Each year, these vehicles are driven about 4.5 billion miles and use about 400 million gallons of gasoline, producing 3.5 million tons of greenhouse gases.

President Biden signed an executive order in January directing federal officials to devise a plan for converting the entire fleet to clean and zero-emission vehicles. So far, the work has been slow.

According to a new report from Atlas Public Policy, accelerating the push for electric vehicles in the federal fleet could save taxpayers billions of dollars.

Electric vehicles have lower fueling and maintenance costs as well as a smaller environmental impact. According to the report, the government could replace 40% of its light-duty vehicles and buses not owned by the Postal Service with cheaper plug-in alternatives by 2025. By 2030, it could replace 97% of such vehicles with EVs for a lifetime savings of more than $1 billion. Furthermore, by 2025, it would be possible to replace nearly all mail trucks with EVs for a savings of $2.9 billion.

The federal fleet represents an opportunity to encourage transportation electrification to happen much more quickly. Apart from the economic and environmental benefits, having an electrified federal fleet would increase public awareness of the practicality and benefits of electric vehicles.

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Push to Electrify Federal Fleet Could Yield Billions in Savings by 2030

Photo, posted May 14, 2015, courtesy of Tony Webster via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.