In the last few years, Simpson Strong-Tie has heard from a number of structural engineers expressing frustration with the lack of performance data for shallowly embedded, post-installed anchors (shallow anchors). Engineers of Record (EOR) have identified a common application for shallow anchors as those related to attachment of sill plates for structural and nonstructural wall-to-podium slab connections. One dilemma faced by the EORs originates in their desire to prevent damage to concrete podium slab reinforcement, especially where reinforcement is located close to the slab’s top surface to resist negative bending moments. EORs further indicate that shallow anchors are frequently needed for the following attachments: hanging MEP fixtures; attaching nonstructural components associated with tenant improvements; and anchoring light equipment.
Simpson Strong-Tie recently had the opportunity to work with MAK Construction to come up with a rather unique solution for a residential project in Phoenix, Arizona. Our Strong Frame® Moment Frame Selector software was used by the engineer on record, L.R. Nelson Consulting Engineers, LLC, to design this truly “special” special moment frame (SMF). The challenge for this particular moment frame design was figuring out how to work around a large garage door opening on the bottom floor without obstructing the window openings on the next floor, because the standard SMF design would cause the beam to cross right through the middle of the windows as they were situated. The solution required dropping the beam below the top of the columns, something seldom seen in moment frame designs. However, our engineering services, in collaboration with L.R. Nelson Consulting Engineers, were able to determine that dropping the beam to the needed level would be quite feasible in this case, and within 24 hours a new design was sent to the EOR and to the contractor for final approvals, which were granted.
We’re pleased to announce that our Composite Strengthening Systems (CSS) code report, ESR-3403, has been revised to recognize Simpson Strong-Tie fiber-reinforced polymers (FRP) for concrete diaphragm applications. These FRP fabrics can be used to strengthen diaphragms for in-plane shear, flexure (chords), and axial tension (collectors) to resist seismic or wind loading.
At Simpson Strong-Tie, we’re always seeking out new opportunities for innovation while helping customers find solutions to new challenges. In fact, “relentless customer focus” and “risk-taking innovation” are two of our nine company values. These two values recently came into play with a challenge to test our Composite Strengthening Systems™ FRP products in a new application on a 17-foot-tall concrete column.
Have you ever been involved on a project where a post-installed anchor failed when loaded? What was the circumstance? Was the anchor installed with incorrect torque or was the hole improperly cleaned, resulting in lower capacities than published? Unfortunately, in the world of concrete anchors, installations are sometimes incorrect as a result of not following instructions. Alternatively, perhaps you’re working on a project where special inspection wasn’t performed as required by the building code. What should be done in these cases?
According to the Greek philosopher Heraclitus, “The only constant in life is change.”
When the latest Wood Construction Connectors catalog (C-C-2019) was published, my colleague, Paul McEntee, PE authored an excellent blog post to announce some big changes within the catalog. He shared that Simpson Strong-Tie® was the first in the industry with updated connector allowable load tables to meet the new ASTM test standards required by the 2015 and 2018 International Building Code® (IBC®). It was one of those rare times where being first didn’t exactly feel like winning.
Let me explain …
Like everyone else in the world, I’ve been spending more time at home these past few months. More than I ever have before. During this time, I’ve found myself thinking about all the home improvement projects that would make our outdoor space more enjoyable. It’s something that in the extreme busyness of our “normal” life, I didn’t have a lot of time for. But being home 24/7 with two energetic and loud little boys has meant a lot of outside time. As a California native, I am grateful to be able to enjoy beautiful outdoor weather most of the year. I love being outside with my family, hanging out in the backyard, escaping all the tempting electronic devices that are constantly pulling us in. And now, more than ever, while sheltering –in place during the COVID-19 pandemic, I’m so thankful for a backyard that we can enjoy. So, topping my backyard home improvement project list: adding a shade structure, like a pergola or pavilion.
The evaluation report, ESR-4057, was recently updated to allow the design of SET-3G adhesive for post-installed reinforcing bars using the ACI 318 development length provision. This blog has been reposted replacing SET-XP with SET-3G using the original design examples. The SET-XP evaluation report, ESR-2508, currently limits f’c to 2,500 psi for seismic applications located in seismic design category C–F. SET-3G does not carry the same limitation allowing for a considerable reduction in development length at higher values of f’c. In general, a substantially lower installation cost can be expected using SET-3G for seismic applications. Additionally, SET-3G has slightly reduced edge and spacing requirements. Engineers can access a free online calculation tool to easily determine the rebar development or lap splice length for either adhesive product.
I first learned about the application of the ACI 318 development length provision to post-installed reinforcing bars back in 2003 when I read Post-Installed Adhesive-Bonded Splices in Bridge Decks, authored by Ronald A. Cook and Scott D. Beesheim. In their series of experiments, holes were drilled adjacent to cast-in-place bars using a carbide-tipped drill bit, and new bars were secured in these holes using an anchoring adhesive presumed to be of a type commonly used in concrete construction.
You never know where the next great product idea or innovation is going to come from — some of our best new ideas originate with the customers who use our current products. At Simpson Strong-Tie, we welcome any inspiration that can help us serve our customers’ needs even better. With so much competition, however, and because so much research and testing are entailed in developing each new product, the criteria that an idea must meet to gain eventual acceptance are necessarily quite rigorous. In this post, Steve Rotzin, Manager of Intellectual Property and Legal Services at Simpson Strong-Tie, outlines some of these criteria for your consideration.
All of us, at one time or another, dream up a product idea of some sort. My wife was once sanding the tongue-and-groove boards of our living room ceiling and she thought of a very cool idea of gloves that had Velcro on them and users could interchange sandpaper of various grit on any finger of the glove. If you’ve ever sanded anything, this actually made a lot of sense especially for complex shapes and tough to reach spots. I researched it and found out that someone had already thought of it and “patented it.”
In 2009, Simpson Strong-Tie participated in an unprecedented research event to highlight the importance of earthquake-resistant wood construction.
The event, the world’s largest earthquake test, was a collaborative Network for Earthquake Engineering Simulation project. It teamed academics, engineers, and industry researchers from around the world to subject a structure to what engineers refer to as the “maximum considered event” (MCE), a large, rare earthquake projected to occur, on average, approximately every 2500 years.