Resilience = Durability + Sustainability



How prepared is global infrastructure for ferocious hurricanes, earthquakes, and other natural disasters? Technical committees are examining the issue from a number of angles.
Jack Maxwell

Cracked walls and broken windows. Muddy water covering furniture, appliances, and memories. A lone chimney standing sentinel over a charred pile of ashes.

Natural disasters like earthquakes, hurricanes, floods, and wildfires test the mettle of every person who surveys scenes like this in their homes. Invariably, in the wake of such tragedies, stories of inspiring strength and courage emerge. Whether it’s first responders working around the clock — even when their own homes are destroyed — or families vowing to rebuild, these and countless other examples define the very essence of the word “resilience.”

But resilience can be viewed in a different context, that of a region’s physical infrastructure. Doing so raises several important questions:

  • How do we assess the vulnerability of buildings to earthquakes, hurricanes, or other hazards?
  • How do we plan and design future infrastructure projects to ensure the greatest possible degree of resiliency?
  • What is the relationship between resilience and sustainability?

ASTM committees are working to answer these questions from a variety of perspectives. Here are some of their efforts.

Resilience Assessment

The U.S. Geological Survey’s website serves as a daily reminder of the extent of global seismic activity. For example, on March 26 of this year, the site listed 11 earthquakes that had occurred around the world as of 11:00 a.m. EST. From a magnitude 4.8 off the coast of Chile to a 2.9 southeast of San Ardo, California.

Seismic activity is of particular interest to lenders, institutional investors, and building owners. These professionals need to understand the relative vulnerability of the properties they bankroll long before the first faint tremors of an earthquake are felt. The hope is that such an event never takes place, but if you’re in the real estate business — especially in higher risk areas like California — you’d better plan for the worst.

E2026 is the standard guide for seismic risk assessment of buildings. It is used to determine a property’s potential for earthquake-related losses caused by ground shaking and site instability, as well as off-site problems like flooding from dam or dike failures.

E2026 “provides standardization for an evaluation of buildings for seismic hazard,” says Josh Marrow, senior associate and director of seismic and structural engineering at Blackstone Consulting, LLC, and chair of the task group working on the standard. “It provides opportunities to identify through real estate transactions, which are quite frequent, hazardous buildings.”

The standard is more than just a tool investors use to evaluate financial risks. E2026 has also contributed to improvements in building resilience. It should have an even greater impact now that provisions have been clarified regarding the qualifications of individuals who do seismic assessmentsz.

Damian Wach is a colleague of Marrow’s on the building performance committee (E06), which is responsible for E2026, and a vice president at PGIM Real Estate Finance. He and Marrow agree that a lack of clarity in the wording of the original standard led some consulting firms to rely on less experienced personnel to do the seismic evaluation field work. “The seismic standards of ASTM did always have requirements that a structural or civil engineer with 10 years of experience in seismic design must write the report. But it didn’t say he or she had to visit the site. It was unclear on that,” says Wach.

The ambiguity found in the previous version of E2026 was cleared up when the most recent update was approved in 2016. “We made the decision to enforce the qualifications as mandatory for certain levels of investigation,” Marrow says.

Wach believes the committee addressed the concerns of industry stakeholders “in a very adept way. Everyone seemed to like it, and it has worked.” Essentially, there are now two tiers of qualifications. A structural or civil engineer with 10 years of experience must now do the field work on older buildings or when structural drawings are unavailable. However, a secondary assessor checking the property’s condition can do the seismic assessment if the building complies with newer, more stringent building codes, or if drawings are available.

The positive impact of E2026 on building resilience can be seen in transactions involving the Federal National Mortgage Association (Fannie Mae), and the Federal Home Loan Mortgage Corp. (Freddie Mac), the two largest lenders in the multi-family space. Josh Marrow notes that “Fannie and Freddie need E2026 guidance because of the volume that’s coming in there. They need to know that they’ve got some consistency in the reporting and that people are qualified, because they will represent that to the federal government.”

More specifically, Marrow believes Fannie and Freddie’s reliance on E2026 has helped make California’s infrastructure more resilient. “A lot of apartment buildings there have what’s known as ‘tuck-under’ parking,” he says. “In southern California it’s more dominant because the lot sizes are smaller, so it isn’t possible to construct an apartment building and then surround it with a parking lot. So parking is located within the building footprint on the first floor, with apartment units above. When the ground shakes, the parking area has no walls to support the seismic forces and the building can collapse, basically pancaking onto the cars.

“Fannie and Freddie have been intolerant to collapse risks like that, so when I have clients who go to them for a loan, we assess the building using E2026 and determine if the risk is unacceptable,” notes Marrow. “oftentimes the borrower will take the loan and retrofit the building. My team has retrofitted more than 200 buildings over the last five years. Not due to a mandatory retrofit ordinance, but because the lender didn’t accept that level of risk tolerance, and the building inventory becomes more resilient.”

Designing Resilience

With no fewer than 18 named storms and three devastating hurricanes — Harvey, Irma, and Maria — the 2017 Atlantic hurricane season was one of the worst on record. Overall damages in the U.S. alone are estimated at more than $200 billion, the most since Hurricane Katrina and the 2005 season.

The U.S. and Caribbean islands were not the only parts of the world to suffer last year. Storms triggered massive mudslides in Sierra Leone, the Danube River in Austria rose to a near-100-year high, and Bangladesh experienced its worst flooding in 40 years.

Most developed nations have extensive infrastructure to manage the flow of water and waste; in the U.S., such systems comprise approximately 2.6 million kilometers (1.6 million miles) of pipe. Plastic is increasingly common, especially for service lines connecting homes to municipal mains, but cast iron (and, to a lesser degree, steel) pipe still represents nearly two-thirds of water system infrastructure. Precast concrete is used for components like storm and sanitary sewer pipelines, culverts, and drainage structures.

In view of the increased demands placed on sanitary and sewage systems by storm-generated floods, the question of just how resilient these systems are, and how they can be designed for greater resilience, becomes increasingly important. Two ASTM International committees are looking for answers.

A member of the committee on concrete pipe (C13) since 1994, Josh Beakley is quite familiar with specification C1478, which covers minimum performance and material requirements for resilient connectors used with precast reinforced concrete components of storm water systems. To Beakley and his colleagues on the committee, resilience is not a new idea in their corner of the infrastructure discussion.

“We have always tried to produce a product that could withstand extreme events,” says Beakley, who is vice president of engineering for the American Concrete Pipe Association. “In fact, it is so ingrained in what we do, that when C1478 was developed in 2000, we were using the term ‘resilient’ in the title to refer to how the connections could adapt to movement. The resiliency of the products with respect to structural strength had long been assumed.”

Beakley points out that resilient connections can adjust to changes in elevation and orientation angles of the joints if they should shift suddenly, as can happen during an earthquake, or when flood waters erode surrounding soil. “While concrete pipe is a rigid structure, C1478 is titled so that people understand that the connections allow for movement within the joints,” he says. “Soil conditions can change, and thus it is important to have both a pipe and connections that can accommodate these changes.”

Of course, the importance of concrete to infrastructure resilience extends well beyond pipes, given the material’s ubiquitous presence in roads, bridges, and buildings. Cesar Constantino, Ph.D., who is director of business development for Separation Technologies LLC, a Titan America business, emphasizes the role ASTM International standards play in ensuring the performance of concrete in these critical applications.

“Cement is one of the ingredients to make concrete,” says Constantino, who is active on several ASTM committees (including those on cement (C01) and concrete (C09)) as well as on the board of directors, and as part of its Ambassador Program. “Along with other supplementary cementitious materials, aggregates, chemical admixtures, and water, adequately proportioned, mixed, placed, finished, and cured concrete mixtures can perform well in diverse applications even when confronting extreme conditions attributable to natural disasters. ASTM has standards for these.”

Constantino also makes a larger point: while ASTM standards address the manufacturing of concrete-making materials, the resilience of concrete elements (columns, beams, and slabs, etc.) and concrete structures (parking garages, buildings, dams and bridges) is directly linked to workmanship, design, and in-service maintenance during their life-cycle. “It is the engineering design, following the building codes, and the construction, following standard guides and practices, that enable the material to withstand earthquakes, floods, and other natural disasters,” he says. “Just like society working together to achieve a common goal, it is ASTM standards, along with building codes and standard concreting practices, that architects, engineers, contractors, and owners — all with resilience in mind — rely on to achieve a desirable outcome.”

Resilience and Sustainability

While numerous ASTM International guides, practices, and specifications support aspects of buildings, pipe networks, and other physical plant categories, standards are also available to help decision-makers plan ahead, improving infrastructure resilience over the long haul.

A good example is the guide for climate resiliency planning and strategy (E3032). “It’s an overall framework,” according to Helen Waldorf, second vice chair of the committee on environmental assessment, risk management, and corrective action (E50), which developed the standard. “The concept is to use climate change maps that have been agreed on by a lot of the studies, which rate the different types of risk in a particular region. For example, the Northeast [U.S.] has a lot of nor’easters, high levels of water, and winds, and astronomical tides.”

Waldorf, who worked for 30 years with the Massachusetts Department of Environmental Protection, explains that the standard doesn’t include specific guidance on risk assessment but rather uses a matrix approach that reflects regional risks based on the historical frequency of extreme weather and other events like fires, floods, and drought.

The subcommittee on environmental risk management (E50.05) is working on a similar guide that focuses specifically on water resources. “After we wrote the general standard to manage climate resiliency, using a regional approach and based on setting priorities, we decided that we needed something a little more specific that follows the same idea,” says Waldorf. This new guide addresses climate resiliency for both water resources (reservoirs, rivers, streams, groundwater, and storage ponds) and the infrastructure for water supply, waste treatment, and agricultural use.

These standards are designed to help stakeholders with long-range infrastructure planning. Nowadays, of course, a key element of any such planning is sustainability – the focus of Committee E60.

But what is the relationship between sustainability and resilience? Michael Schmeida, director of technical services for the Gypsum Association and a former E60 chairman, believes that “Resilience is really the next step, or maybe a different way of looking at sustainability, because if items are lasting beyond these kinds of events where normally a wall would be replaced or a roof would need to be replaced, that’s sustainable, you’re not utilizing as many resources in the long term. You’re preserving those resources.”

To promote the notion that infrastructure and resilience are connected, the committee decided to develop a standard guide for evaluating material resilience in systems. “We were finding a lot of discussions on resiliency are at the very macro, or community, level,” says Schmeida. “Examples include New Orleans after [Hurricane] Katrina, or the Jersey shore after [Hurricane] Sandy. Obviously, the community being able to come back and at least function at a basic level is important. But anything is also only as good as the sum of the parts. So you have to start with systems that are going to be able to withstand what they should be able to withstand.”

Committee members began work on the standard guide about a year ago. According to Schmeida, the goal is “getting people to specify, or pushing them in the direction of specifying, the right materials for the specific system and situation. Because that ultimately is what will give you better resiliency.”

Pushing stakeholders in the direction of improved resilience is the ultimate goal of all the ASTM International committees that work in the infrastructure space. Whether it’s risk assessment guides driving building improvements in earthquake-prone areas, or material specifications that help ensure the integrity of water and sewage systems, or standards that promote a holistic approach to the relationship between sustainability and long-term durability, the efforts of the many dedicated individuals who volunteer their time and effort on these committees are making a tangible difference in the built environment around the world.

 

Jack Maxwell is a freelance writer based in Westmont, New Jersey. 

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