Structural Engineers Face Climate Change Obstacles
Regardless of the cause, it has been well documented that the Earth’s average temperature is warming. Scientists predict that temperatures will increase by between 1°C and 2.5°C. A rise of 3°C or more could be disastrous, and governments are feverishly working to minimize the human effect on climate change as much as possible.
For structural engineers, climate change poses a particular problem. The temperature distribution in a concrete structure varies due to complex interactions with the surrounding climate. For example, solar radiation, air temperature, humidity, wind speed, and long-wave radiation all affect the temperature in the material and may cause movements in the longitudinal and transversal directions. If these movements are restrained, stresses and strains can be induced, which may contribute to cracking and other structural problems. Thus, a change in the climate may significantly impact the thermal actions and behavior of a structure.
The structural values defined in building codes are based on climate data calculations. The climate data used to calculate the design values for thermal actions was obtained during the last half of the 20th century. With more evidence of climate change and the rise in the average temperature over the past 20 years, the design values for thermal actions may have become outdated.
One recent technical study shows that the design values for uniform bridge temperature must be updated to incorporate the effects of climate change. One suggested way is to couple the design value to the service life and estimate the temperature change for a specific location based on the climate models. However, further studies and detailed climate models are needed for any conclusions.
Regardless of the models and code changes, structural engineers can play an essential role in minimizing a building’s contribution to global climate change by implementing alternative design approaches.
One of the most impactful decisions made by a structural engineer is the selection of materials. In addition, an engineer can minimize a building’s contribution to global climate change by considering manufacturing techniques and product life cycles.
The most significant contributor to atmospheric carbon (CO2) is cement. For every ton of Portland cement manufactured, one ton of CO2 is released into the atmosphere. As shown in this video, using less Portland Cement or cement alternatives is the answer for the future. Some suggested options are:
- Concrete made from granulated blast-furnace slag, a byproduct of steel manufacturing
- Concrete made with Geopolymer cement instead of Portland Cement
- Concrete made with recycled aggregate
- Concrete made with carbon-capture aggregate
Steel is another construction material with high carbon content. However, low-carbon steel with a 0.3% carbon content is a viable alternative for most construction projects. Chosen for its unique structural properties, low carbon steel has good enough strength for building frames in construction projects. In addition, it meets seismic and wind requirements, cannot be damaged by insects, and is impervious to rot and fire.
Fortunately, steel is 100% recyclable, and choosing recycled steel also reduces the amount of atmospheric CO2 produced. At INNOVA Technologies, we are always looking for ways to improve the performance of the structures we design while protecting the environment. To learn more about our services, go to https://innovanv.com/ or call 702-220-6640