The Structural Engineering Channel focuses on helping structural engineering professionals stay up to date on technical trends in the field. The podcast also features professional development topics for structural engineers to facilitate career advancement. Specifics topics to covered on the podcast include but are not limited to performance-based design, fasteners and connections, post-tensioned structures, smart structures, tsunami modeling, earthquake engineering, software solutions, seismic design, blast resistant design, wood, business issues and professional development for structural engineers, how to specify things effectively, and more.
TSEC 43: Evaluating Low Concrete Strength Results
In this episode, we talk to Matthew Karalus, P.E., a field technician from the ECS Group of Companies, about low concrete strength and some of the methods used to test for concrete strength.
Here Are Some of the Questions We Ask Matthew:
Why is it so important to conduct a concrete strength test?
Are the concrete strength tests conducted while the concrete has been poured, or after it has already cured, or both?
What are some of the methods you use for on-site testing of concrete strength?
Are there any additional curing steps to ensure the same is happening to the poured concrete?
What are some of the causes of low concrete strength results?
When low concrete strength test results are obtained from test cylinders, what are the steps you take?
What is non-destructive testing, and when would you use it?
What are some of the additional testing methods that are less common but are still usable?
Would you like to share some career insights or wisdom?
Here Are Some of the Key Points Discussed About Conducting Concrete Tests:
Some of the concrete strength tests are:
Batch replacement time concrete test: There is a 90-minute window between when the concrete is mixed with water until it needs to be out of the truck. The longer the concrete is turning in the truck, the more it loses its strength.
Concrete temperature test: If concrete gets too hot, it will dry out and not hydrate properly. If the concrete freezes, it can become brittle. Field samples are placed under a concrete blanket by the poured concrete. If the field samples have frozen, then it is highly likely the poured concrete also froze.
The viscosity of the concrete: If you have a plasticizer in the concrete, it raises the viscosity, or slump. You will not need concrete with high viscosity in places where you need the concrete to remain in a specific shape.
Entrained air content: Interior concrete usually has no entrained air content, while most exterior concrete does. Exterior concrete needs entrained air to help with the long-term durability of the concrete by giving it room to flex.
Concrete strength tests are mainly performed before or during the pouring of the concrete. In some cases, the structural engineer might request tests to be done sometime after the concrete has hardened because the slab needs to be lifted from horizontal to vertical for concrete walls.
Casting cylinders is the main way to perform a concrete strength test. There are two ways to cure these cylinders: field-cured cylinders and laboratory-cured cylinders. Field-cured cylinders are used for testing concrete strength in places with low temperatures. Laboratory-cured cylinders are used to find the optimal strength of the concrete after 28 days.
One of the main causes of a low concrete test result is an incorrect concrete/water mix. The structural engineer is then notified about this and it is up to him to decide if he wants to use the concrete or not, as it could fail later.
If concrete strength test results are low, there are a few things that need to be considered:
There are statistical acceptances in place for concrete when the test results are slightly low, which is within 500psi of the required strength.
The structural engineer can also run tests to see if the concrete strength is acceptable for the location.
If the curing cylinders are still not meeting the standards at the 28-day stage, spear cylinders are then left for an additional 28 days to see if the concrete still does not match the requirements. This additional time can show a 20% increase in strength and could then be close enough to the requirements.
The traditional destructive testing method means to take a co...
TSEC 42: Seismic Upgrades To the Museum of Anthropology (MOA)
Photo by Brannen Bell, courtesy of the Museum of Anthropology at UBC.
In this episode, we talk to three people who are involved in seismic upgrades to a Heritage Designated World Recognizable Work of Architecture, the Museum of Anthropology (MOA) in Canada. They are Nick Milkovich, Principal at Nick Milkovich Architects Inc. Who is also the principal architect for the upgrade, Aletha Utimati, Project Manager at The University of British Columbia and for the Great Hall renewal project, and 5013 and Eric Karsh, a structural engineer and principal at Equilibrium Consulting Inc and a leader in timber engineering and construction. They talk about some of the seismic upgrades planned at the Museum of Anthropology.
Here Are Some of the Questions We Ask Our Guests:
Tell us what your job will entail in the process?
Why is the University of British Columbia undertaking this project?
Tell us about the experience of working with the late Arthur Erickson, what it meant to you, and how it affects your perspective on this project?
Tell us more about using base isolation technology and vertical glass upgrades and its challenges.
What are some of the challenges of doing construction beside a working museum?
How will the differential seismic movement between the Great Hall and the rest of the museum influence the construction process?
How do they plan to protect the massive wooden carvings and poles that reside in the Great Hall during construction?
What does it take to become an expert on a specific design process or material for a structural engineering professional?
Here Are Some of the Key Points Discussed About the Seismic Upgrades To the Museum of Anthropology:
The Great Hall has a tall and slender design and is wrapped in glass, which makes it susceptible to seismic forces. The structure needs to be preserved while bringing it up to code, without changing the architecture.
The seismic upgrades need to be done on the Great Hall as it is one of the high-risk areas on the campus. This was found through a comprehensive evaluation of seismic risk across all buildings, utilities, and assets on the campus. The seismic upgrades are not only being done for human safety but to also preserve the museum's invaluable collection if a seismic event had to happen.
Arthur Erickson’s office was an interesting place and felt like a continuation of school. Anyone could come up with ideas to be discussed, debated, and implemented. The concept behind the museum was based on a photograph that Arthur saw villages on Anthony Island which were all close to the beach. The movement through the museum represents the movement from the forest, across the beach, and ending by the water. Arthur was interested in the proportional experiences that people would have when walking through the museum.
Because of the museum’s heritage properties, traditional seismic upgrades are not an option. The introduction of additional elements or braces could not be hidden anywhere, and the structure is an integral part of the architecture. This means that anything you do to the structure impacts the original work, which is something that was committed to avoid.
Base isolation means to disconnect the building from the ground and put it on a bed of jello which will significantly reduce the seismic loads on the structure. This however was not enough for the great hall to not get structural damage and the glass on the building would also suffer damage in a seismic event. This means that the entire building is needing to be rebuilt to mirror the old building but will structurally meet the code. The original glass was not detailed to accommodate much movement. The rebuild allowed redesigning the interface between the glass panels and the structure t...
TSEC 41: An Overview of Masonry in Structural Engineering
In this episode, we talk to Brian Trimble, P.E., a director of Industry Development at the International Masonry Institute. He talks about masonry, optimizing structural masonry, the importance of teamwork, and why getting out in the field is so important in your engineering career.
Here Are Some of the Questions We Ask Brian Trimble, P.E.:
Can you please explain what masonry is and what the difference is between brick and masonry?
Do you have any tips that you can share with our listeners for making structural masonry better and more cost-effective?
How have the masonry codes changed lately, and where are they heading in the next few years?
What happens when you combine brick with other materials such as metal or wood?
What advice can you provide about the importance of getting out in the field?
Why do you believe that craftworkers may know how things get put together sometimes more than a designer?
How can you use materials to their fullest in construction?
What is your opinion about structural engineering not always being about crunching numbers, but that it often requires collaboration with other team members and those in the field?
What advice would you give engineers who are considering a career in construction engineering?
Here Are Some of the Key Points Discussed About Masonry in Structural Engineering
Masonry is anything that is set in mortar or uses a masonry material. Anything that deals with brick, block, stone, terrazzo, concrete finishing, and restoration falls under the masonry umbrella.
Overdesign of masonry can impact the cost of masonry projects. It usually happens because of a lack of understanding when it comes to masonry design. Engineers tend to do more redundant systems because they feel uncomfortable when working with masonry. Engineers need to stay up to date regarding the developments in masonry materials to further lower costs.
Lots of research has gone into making the masonry codes, and they have gotten better over time. The 2016 code is the current version, and the 2022 version is currently in production. The codes have switched to a six-year cycle instead of a three-year cycle. Doing this ensures engineers can keep up with all the changes. The switch to a six-year cycle has its benefits, such as doing more thorough research.
Masonry and materials like wood and steel are very compatible, and can be combined. Without materials like reinforcing steel, masonry could not have gone to where it is now. When working with different materials, you need a knowledge of the properties of each material. One of the main things you need to know about is how differential movement will impact each material. These properties need to be recognized and planned for in the design process.
You need to know about structural engineering to work with masonry. It is important to have experience with what gets built in the field. Instead of walking straight into the design office, try to get an internship where you can see how mortar work is done and hear about some of the concerns brought to the table.
The engineer, contractor, and all the other team members need to get together collaboratively. The more times you are talking things out, the better things are. By doing this, any conflicts or differences in opinions can be dealt with sooner rather than later.
People look at masonry for its aesthetics when it is a strong material and implemented in many load-bearing applications. When combining materials with masonry, look for materials that can be used for multiple purposes. Masonry is very resilient and contributes to having safe structures to work and live in.
There is a lot of information about masonry available to designers.
TSEC 40: Tips on Preparing for the SE Exam (From a Recent SE Examinee)
In this episode, I interview my co-host Mat Picardal, who recently took the SE Exam. He talks about his experience taking and preparing for the SE Exam, what the exam is, why it's so difficult, and the benefits of earning a SE licensure.
Here Are Some of the Questions I Ask Mat:
What is the SE exam and where is it required or recommended?
What is the difference between the PE Structural and the SE exam?
Why is the SE exam so difficult and why is the pass rate at 30%?
What was the toughest part for you in preparing for the exam?
What preparation resources are out there?
How did you prepare for your SE?
What was the first thing you did to celebrate finishing this momentous career milestone?
What do you recommend others do when considering, preparing for, and taking the exam?
Here Are Some of the Key Points Discussed About Preparing for the SE Exam:
The SE exam is a specialty license that you get for structural engineering. It is an advanced license that allows you to work on more advanced projects like risk category 4 buildings and high-rise buildings. It is not required in all the states, but is a requirement in the state of California.
After you get your P.E. license, you need to be working under an SE licensed structural engineer for three years before you can take the SE license exam. The difference between the P.E. and SE exams is the SE is all structural engineering topics and subjects and it is much more difficult. You need to study for around 100 hours to prepare for the PE exam, whereas 300 to 400 hours of studying is required for the SE exam.
If you are thinking of taking the SE exam, you need to look at your long-term career goals and see if it will be necessary. You need to consider that preparing for the exam is a big commitment that does take a long time, and you need to do it all over again if you do not pass the exam.
By preparing for and taking the SE exam, many of the structural engineering gaps get filled in, which will make you a better engineer. You will have confidence in knowing how to deal with and approach any material or project that you get. Even if it is not required in your state, you should look at it as a future investment in your career.
When preparing for the SE exam, you can split up the exam into two parts, namely the lateral side and the gravity side. Most people do not recommend taking both parts of the exam at the same time because both sections have a lot to learn and remember. It is also recommended that you take a class, which will give you a tighter schedule and keep you accountable. In addition, you will be guided by someone who will show you where people make mistakes, what parts you need to focus on, and what is going to be in the exam.
Of the 400 hours, 100 of them are spent in the class, and the remaining 300 hours are devoted to studying time, which consists mainly of solving many problems by hand and not using a computer. One of the most challenging parts is the sheer number of subjects that you need to learn about.
The gravity test is more difficult than the lateral test because it is an extensively broad section. You will need to know about things like bridge design, which is something that you probably have never done as a structural engineer.
There are a couple of different ways for you to prepare for the exam, like taking a course or self-studying. A good list of resources for self-studying can be found if you Google “NCSEA SE Exam Study Guide” It consists of references, study guides, code books, and guides for studying for the SE. There are many classes that you can take that include things like summarized sections, which can save you many hours of study time.
If you are thinking of taking the SE exam,
TSEC 39: The Difference Between Construction Engineering and Structural Engineering
In this episode, we talk to Andrew (Drew) Twarek, a project manager at Ruby+Associates, Inc. Structural Engineers about construction engineering, what it is and how it differs from structural engineering. He also talks about some of the top award-winning projects that he’s worked on in the past.
Here Are Some of the Questions We Ask Drew Twarek about Construction Engineering:
What is construction engineering and how does it differ from “regular” structural engineering?
Why do you think contractors need a construction engineer?
What does a construction engineering project look like?
What are some of the real-life construction projects that Ruby+Associates has been involved with?
Can you talk to us about the five-mile long suspension bridge painting project that won you the NCSEA Engineering award?
Talk to us about the project you worked on with Colorado Springs Utilities, where innovative technology to reduce SO2 emissions at one of its power plants was used.
What advice can you give to engineers considering a career in construction engineering?
Here Are Some of the Key Points Discussed About Construction Engineering:
There are many different types of constructional engineering, such as connection design, erection procedure engineering, and construction engineering. Construction engineering is a branch of structural engineering but is separate from the typical structural engineering. Constructional engineering involves the construction process, planning, scheduling, manpower, labor, and material input that goes into the projects. It also involves solving structural engineering problems, how the materials are used, and helping the client to get the project built.
Some examples of what constructional engineers work on are:
Construction equipment loading on the already constructed parts of the project.
Demolition design and stability analysis if parts of the building need to be removed or if new portions of the building need to be added underneath the already constructed building.
Analyzing construction repairs to see if it needs to be demolished or if the construction that is there can be used and improved on.
Contractors need construction engineers to ensure the safety of the workers and structure in the design phase, when they have construction issues that they need to solve or run into problems that need repairing.
Andrew was part of the award-winning project of painting the iconic five-mile long Mackinac suspension bridge in Michigan. They designed a one-of-a-kind platform to replace the scaffolding, transporting the painter's up and down the towers of the bridge while they removed the old paint and replaced it with new high-tech paint.
Andrew also worked on a project with Colorado Springs Utilities where innovative technology to reduce SO2 emissions at one of its power plants was used. They used a combination of reinforced fiberglass (FRP) with a steel exoskeleton. The fiberglass is used in tanks and pipes that are made of corrosive materials but rarely used in ductwork. The entire duct was made from fiberglass and enveloped in structural steel to enhance the strength of the duct. They faced challenges in joining the two materials together because the structural steel needed to have space for the fiberglass to expand and contract.
If you are thinking of moving to a construction engineering field, you need to pay attention to your steel, concrete, timber, and statics classes. Get experience in the field because it helps to see the construction process, and you will learn how to deal with contractors and get onboard with them.
CLICK HERE TO VIEW THE MODERN STEEL CONSTRUCTION ARTICLE PHOTOS
TSEC 38: The Benefits and Common Pitfalls of Mass Timber in Structural Engineering
In this episode, we talk to Ricky McLain, P.E., SE, who is the Senior Technical Director at Tall Wood, WoodWorks about mass timber in structural engineering — what it is, some of the common pitfalls for mass timber projects, and how structural engineers can play a significant role in setting a mass timber project up for success.
Here Are Some of the Questions We Ask Ricky in This Episode:
What is mass timber?
Why is mass timber suddenly so relevant to structures in the United States now?
How can a structural engineer promote the use of mass timber to their clients?
What are some of common pitfalls in a mass timber project?
How can engineers determine what products each manufacturer is producing?
How can structural engineers play a significant role in setting a mass timber project up for success?
In what ways can an engineer use mass timber as a differentiating opportunity for their business development strategy?
Here Are Some of the Key Points Discussed About Mass Timber in Structural Engineering:
Mass timber is an umbrella term that encompasses a large number of products, e.g., CLT (cross-laminated timber), and is similar to heavy timber construction. Most of the products use a small dimensional lumber combined together to create a larger cross-section.
Mass timber was first introduced to the marketplace in terms of building construction about 30 years ago in Europe, and has been used extensively internationally for the past two to three decades. It has only really been used more frequently in the U.S. in the last six to seven years.
As the global population, including the U.S. population, continues to grow, there is a significant shift to more urban occupancy. Building design professionals have started to realize that they play an especially important role in the environmental responsibility and sustainability of the buildings. Because a significant focus is being placed on the embodied carbon of the materials being used in a structure, and because structural elements in a building make up a huge part of that piece of a carbon pie, there are more people starting to look at mass timber as a way to potentially reduce the carbon impact of construction materials. These factors coming together is what started the movement of mass timber.
When structural engineers want to promote the use of mass timber to their clients, they need to first understand the material and why it could benefit a specific project.
Mass timber is not a commodity product, as each manufacturer may be using a slightly different species/grade/thickness of wood. Structural engineers must work together with their manufacturers and really understand their manufacturers’ capabilities and supply chain.
The list of mass timber manufacturers is not very long, so it is worth reaching out to each one of them to get to know them and their products.
A mass timber project from start of design to finish of construction has the possibility of being a quicker process when working with a manufacturer earlier on throughout your design process.
Structural engineers play a significant role in setting a mass timber project up for success. They should get some experience with and understanding of different construction types and fire-resistant readings, and understand how the timber elements can meet them.
Structural engineers can use mass timber as a differentiator in their business development strategy because at this point, it is still relatively new. Depending on which city you are in, you might be doing the first mass timber project there.
More Details in This Episode…
About Ricky McLain, P.E., SE
Ricky is WoodWorks’ in-house expert on tall wood buildings,