Pouring Ice Into Concrete: Builders Adapt to Extreme Heat

Roads, bridges and train tracks built to the design standards of the 20th century are buckling from extreme heat gripping the globe. Power grids, buildings and cooling systems are under strain.

Design standards have failed to keep up with a warming climate, say engineering and construction experts who are pushing their clients to invest in solutions to make existing buildings cooler while factoring in the cost of future heat waves. 

“The U.S. isn’t prepared for what we’ve had so far, let alone more of it,” said Adam Jaffe, senior materials engineer at Arup, a global design and architecture firm, about extreme heat.

Throughout July, record-setting temperatures have broiled the southern half of the U.S., southern Europe, central China and eastern Asia. The heat has caused scattered power outages in several countries and buckled roads in Utah, Louisiana and Wisconsin, according to local news reports. In Texas, a section of Interstate 10 in Houston and a six-lane state highway south of the city ruptured during 100-plus-degree heat in late June.

As roadways absorb heat, asphalt—which is used on more than 90% of U.S. roads—begins to melt and deform, forming bumps and ripples on the road surface. This leads to a rougher ride, more fuel consumption, more emissions and higher vehicle-maintenance costs, according to Imad Al-Qadi, director of the Illinois Center for Transportation at the University of Illinois at Urbana-Champaign. 

On concrete highways, steel joints designed to allow the surfaces to expand to prevent cracking can fail if the roadway gets too hot.

Buckled roads are relatively easy to spot and fix, but the effects of heat on buildings, pipes and electrical structures are less evident. Extreme heat wears down buildings over time and can lead to big repair bills, according to Elaine Gallagher Adams, an architect and net zero facilities solutions leader at Arcadis, a design and consulting firm. 

Sealants, glues and other polymer-based adhesives that hold together pipes, windows and structural joints are the materials most vulnerable to heat, she said. When they crack, it can lead to water leaks.

Temperatures experienced by polymer sealants might be substantially higher than the air temperature. For example, if it is 120 degrees outside, certain building facades exposed to sun might reach 180 degrees, and the sealants will likely be somewhere in between, said Jaffe.

Extreme heat also poses risks to metal and concrete materials used during construction.

In Phoenix, three weeks of 110-degree plus temperatures are expanding steel plates and iron girders used in building projects across the region, according to Reymundo Hernandez, a field representative for the Bricklayers and Allied Craftworkers Local 3, which represents trade union workers in Arizona and New Mexico. 

That makes it more difficult for workers to set beams into concrete blocks and walls, and could lead to problems later on, Hernandez said. “When you are setting beams into concrete, and it’s so hot right now that they swell more, then you get cracks in the walls.”

The extreme heat has led some builders to add buckets of ice to concrete and mortar to help it set properly. And they schedule pours at night, when the temperature gets down to the mid-90s, according to Matt Gilliland, risk manager for Phoenix-based Willmeng Construction. 

“We are adapting,” Gilliland said.

Joints that hold bridges together also expand during heat, making construction and repair work tricky. “Those things can move a couple inches on the weather,” Gilliland said. “You may fit it up in the morning, and when the time is ready to set it, you may have a problem in the afternoon.”

Architects say glass-and-steel skyscrapers that dominate many urban skylines are particularly unsuited to cope with rising global temperatures. They are often poorly insulated and require massive cooling systems that will need to be upgraded as outdoor temperatures rise. 

Glass-facade buildings also reflect sunlight and contribute to the urban heat island effect, a phenomenon where buildings, roads and other surfaces absorb and re-emit the sun’s heat. Cities become “islands” of higher temperatures relative to greener outlying areas, up to 7 degrees Fahrenheit warmer during the day and 5 degrees warmer at night, according to the U.S. Environmental Protection Agency.

To keep air conditioners running during future extreme heat events, researchers say the systems will have to become more energy-efficient. The demand for summer air cooling is expected to rise 13% over the current load in the U.S. if average global temperatures rise by 2 degrees Celsius, or 3.6 degrees Fahrenheit, according to a study by researchers at the University of Maryland and Purdue University. 

Without improvements in cooling technology, many households throughout the U.S. could face up to 14 days without air conditioning due to power outages in a given summer in a warmer world, the authors wrote.

During a 2021 heat wave in British Columbia, more than 400 transformers failed, affecting the function of cooling systems in homes, businesses and institutions in many parts of the province, according to a June report by the Canadian Climate Institute, a nonprofit research organization.

Adapting to climate change leaves businesses, utilities and property owners with some tough and expensive choices, according to George Karagiannis, an expert in engineering and critical infrastructure at Resilience First, a business network based in London. 

One recent study found that increased extreme heat across the U.K. and Europe could boost yearly operational and maintenance costs to roads and rail systems up to $5.4 billion by 2100, depending on how much the atmosphere warms.

Karagiannis said it would be too expensive to update all the infrastructure that isn’t equipped to deal with extreme heat and other threats posed by climate change. Instead, he said policy makers and companies will have to build better systems for responding to and recovering from weather emergencies while giving priority to the most urgent retrofits. 

“Most of our existing infrastructure was designed based on temperature averages 60 to 80 years ago,” he said, “but these aren’t the conditions we are facing today.”

Write to Eric Niiler at [email protected] and Ed Ballard at [email protected]