Case Study: RPS solutions renew popular event structures after Hurricane Harvey damage

Background — Beach pavilions required repair both for column decay and for extensive hurricane damage.

The two pavilions at Rockport Beach Park in Rockport, Texas, have been serving as popular rentals for large weddings, family anniversaries and other events for more than 30 years. The pavilions are elevated approximately 20’above the beach on concrete slabs and columns. Other structural features include CMU and wood roofs.

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Reasons to Specify SET-3G Adhesive for Anchorage in Concrete Construction

Weve been receiving a lot of requests lately from engineers wanting to know exactly what the difference is between Simpson Strong-Tie’s relatively new adhesive, SET-3G, and its predecessor, SET-XP®. Both are epoxy-based adhesives used to anchor threaded rods and reinforcing bars in concrete base material for structural applicationsIf you perform a live pull test on a ½“-diameter mild steel rod embedded 4 deep in 3,000 psi uncracked normal-weight concrete, the result will likely be the samein both cases, the steel rod will break in a ductile manner at around 11 kips. You can see this hourglass-shaped steel failure mode happening in Figure 1. (To learn more about anchorage failure modes and ductility, check out this blog). Yet, the SET-3G design values shown in ESR-4057 come out ahead. But why? 

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Risk-Taking Innovation Leads to New FRP Strengthening Application

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.

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Case Study: Manzanita Hall

Manzanita Hall is one of three remaining buildings on the University of Nevada, Reno, campus that were constructed prior to 1900. Originally named the Girls’ Cottage, Manzanita Hall was built in 1896 and was used to house 97 women in double and single rooms. Architecturally, it a created a Victorian atmosphere and offered a spacious student lounge, complete with a grand piano and a spectacular view of Manzanita Lake.

Several years ago, the hall was deemed seismically inadequate, and the electrical, plumbing and HVAC systems were likewise found to be seriously outdated and insufficient for modern college life. These structural deficiencies necessitated its closure in 2015.

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New CSS Product Launch — FRCM Strengthening Products

The new FRCM Composite Strengthening Systems™ repair and reinforcement solution from Simpson Strong-Tie combines high-performance sprayable mortar with a carbon-fiber grid that creates a thin structural layer that repairs and strengthens without significantly increasing the structure’s weight or volume. FRCM stands for fabric-reinforced cementitious matrix. Its advantages are similar to those of FRP (that is, strength, low weight and ease of application), but it may also be used to repair, resurface, strengthen and protect in one application, along with providing greater resistance to heat and better long-term durability.
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A New Way to See Whether FRP Is Right for Your Project

Specifying our Composite Strengthening Systems™ (CSS) is unlike choosing any other product we offer. In light of the unique variables involved with selecting and using fiber-reinforced polymer (FRP) solutions, we encourage you to leverage our expertise to help with your FRP strengthening designs. To get started, we first need to determine whether FRP is right for your project. The fastest way to do that is for you to fill out our FRP Design Questionnaire. Our new Excel-based questionnaire collects your project information and helps you use the existing capacity check to evaluate whether or not FRP is suitable for your project per the requirements of ACI 562-16 Section 5.5.2. After the feasibility study, the questionnaire creates input sheets specifically for your project.
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What’s New in the ACI 440.2R-17?

The wait is over. The ACI 440.2R-17 Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures is now available. The following post will highlight some of the major changes represented by this version of the document.

It’s been a long road and countless committee hours to get from the last version of ACI 440.2R-08 to this document. While there are multiple smaller changes throughout the document, the most notable update is the addition of Chapter 13 – Seismic Strengthening.

 

The new seismic chapter addresses the following FRP strengthening scenarios:

  • Section 13.3 – Confinement with FRP
    • This section includes all of the following: general considerations; plastic hinge region confinement; lap splice clamping; preventative buckling of flexural steel bars.
  • Section 13.4 – Flexural Strengthening
    • The flexural capacity of reinforced concrete beams and columns in expected plastic hinge regions can be enhanced using FRP only in cases where strengthening will transfer inelastic deformations from the strengthened region to other locations in the member or the structure that are able to handle the ensuing ductility demands.
  • Section 13.5 – Shear Strengthening
    • To enhance the seismic behavior of concrete members, FRP can be used to prevent brittle failures and promote the development of plastic hinges.
  • Section 13.6 – Beam-Column Joints
    • This section covers a great deal of recent research on the design and reinforcement of beam-column joints.
  • Section 13.7 – Strengthening Reinforced Concrete Shear Walls
    • This section provides many recommendations for FRP strengthening of R/C shear walls.

Simpson Strong-Tie Can Help

We recognize that specifying Simpson Strong-Tie® Composite Strengthening Systems™ (CSS) is unlike choosing any other product we offer. Leverage our expertise to help with your FRP strengthening designs. Our experienced technical representatives and licensed professional engineers provide complimentary design services and support – serving as your partner throughout the entire project cycle.

For complete information regarding specific products suitable to your unique situation or condition, please visit strongtie.com/css or call your local Simpson Strong-Tie RPS Specialist at (800) 999-5099.

Upcoming Free Webinar: Advanced FRP Design Principles

Join us live on July 25 for the second interactive webinar in the Simpson Strong-Tie FRP Best Practices Series: Advanced FRP Design Principles. In this webinar we will highlight some very important considerations during the FRP design processes. This will include topics such as the latest industry standards, proper use of material properties, and key governing limits when designing with FRP. Attendees will also have an opportunity to pose questions to our engineering team during the event. Continuing educations units will be offered for attending this webinar. 

Learn more: Webinar – Introducing Fabric-Reinforced Cementitious Matrix (FRCM)

In this free webinar we dive into some very important considerations including the latest industry standards, material properties and key governing limits when designing with FRCM.

Continuing education credits will be offered for this webinar.
Participants can earn one professional development hour (PDH) or 0.1 continuing education unit (CEU).


4 Common FRP Myths and Misconceptions: The Stuff Not Everyone Talks About

The primary benefit of fiber-reinforced polymer (FRP) systems as compared with traditional retrofit methods is that significant flexural, axial or shear strength gains can be realized using an easy-to-apply composite that does not add significant weight or section to the structure. Many times it is the most economical choice given the reduced preparation and labor costs and may be installed without taking the structure out of service. However, it is important to make sure the composite is properly designed following industry standards in order to ensure that it is the right product for the application.

To provide you with a better understanding of the topic, it’s important to dispel some common myths and misconceptions that you might hear about FRP:

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Q&A: Best Practices for FRP Strengthening Design

frp-design-banner

On December 1, 2016, Simpson Strong-Tie hosted a webinar titled “The Design Fundamentals of FRP Strengthening” in which Justin Streim, P.E. – one of our Field Engineers – and I discussed the best practices for fiber-reinforced polymer (FRP) strengthening design. The webinar examines FRP components, applications and installation. It also features an example of the evaluation that went into a flexural-beam-strengthening design and discusses the assistance and support Simpson Strong-Tie Engineering Services offers from initial project assessment to installation. Watch the on-demand webinar and earn PDH and CEU credits here.

During the live webinar, we had the pleasure of presenting to more than 1,500 engineers who asked nearly 300 questions during the Q&A session. Here is a curated selection of Q&A from that session:

q-a-graphic

Can you discuss the flexural strengthening for reinforced masonry walls?

Out-of-plane flexural strengthening can be provided with FRP on the required face of wall. In-plane (or shear wall type) flexural strengthening can also be provided with vertical FRP strips near the ends of walls.

In general, by what percentage can FRP solutions increase the strength of existing concrete shearwalls?

This really depends on the existing wall, but we have seen strength increases of 22% in our testing of one layer of glass fabric installed on 8″ thick ungrouted CMU shearwall.

How does FRP compete in terms of cost? It seems like a cost-prohibitive solution compared to other remediation techniques in the absence of other limiting factors (space limitations, etc.).

FRP may be expensive on a cost/SF basis. However, if you compare it with the materials and labor involved in section enlargement or demolishing parts of buildings, it becomes cost effective. FRP installations are also not unsightly like bolted steel plates or wide flange members slung under concrete slabs/beams.

Who designs the FRP system: Simpson Strong-Tie or the Structural Designer?

The Simpson Strong-Tie Engineering Services group provides the FRP design on most projects, but we have also worked with the engineer on record (EOR) to check their FRP design on projects.

Are there any deformation compatibility issues between carbon fiber or glass and existing reinforcing bar that need to be accounted for in design? Is long-term creep similar to that seen with reinforcing bar?

CFRP and GFRP have different elastic moduli from each other and from steel. When designing an FRP strengthening solution, these differences must be taken into account. For flexural applications, the FRP should be designed to fail from debonding after the internal rebar begins to yield. Creep is taken into account in design equations through reduction factors and stress checks.

Will ACI 440 be updated to include the use of FRP with post-tensioned beams (i.e., unbonded tendons)? Does Simpson Strong-Tie do all stress checks based on gross section properties when total stress is < 12sqrtf’c?

Yes, there is an ACI 440 committee working on including an unbonded PT section in ACI 440.2R. We will work with the EOR to determine what section properties are most appropriate for the specific member being evaluated.

Can you increase deflection limits with FRP?

While FRP does help to limit deflection in members, members with deflection issues are not typically candidates for FRP repair. Prestressed laminates as used in Europe would be a better solution for a member with deflection issues. We do not currently offer prestressed laminates but may in the future.

Does an aesthetic coating interfere with bridge inspection? What is inspection looking for? Delamination or other defects?

A coating could interfere with a visual inspection of the FRP surface. A visual inspection can reveal changes in color, debonding, peeling, blistering, cracking, crazing, deflections, indications of reinforcing-bar corrosion, and other anomalies. In addition, ultrasonic, acoustic sounding (hammer tap) and thermographic tests may indicate signs of progressive delamination. ACI 440 and AC 178 have extensive special inspection recommendations.

Learn more: Webinar – Introducing Fabric-Reinforced Cementitious Matrix (FRCM)

In this free webinar we dive into some very important considerations including the latest industry standards, material properties and key governing limits when designing with FRCM.

Continuing education credits will be offered for this webinar.
Participants can earn one professional development hour (PDH) or 0.1 continuing education unit (CEU).


For complete information regarding specific products suitable to your unique situation or condition, please visit strongtie.com/css or call your local Simpson Strong-Tie RPS specialist at (800) 999-5099.

 

Q&A: Best Practices for FRP Strengthening Design

frp-design-banner
On December 1, 2016, Simpson Strong-Tie hosted a webinar titled “The Design Fundamentals of FRP Strengthening” in which Justin Streim, P.E. – one of our Field Engineers – and I discussed the best practices for fiber-reinforced polymer (FRP) strengthening design. The webinar examines FRP components, applications and installation. It also features an example of the evaluation that went into a flexural-beam-strengthening design and discusses the assistance and support Simpson Strong-Tie Engineering Services offers from initial project assessment to installation. Watch the on-demand webinar and earn PDH and CEU credits here.
During the live webinar, we had the pleasure of presenting to more than 1,500 engineers who asked nearly 300 questions during the Q&A session. Here is a curated selection of Q&A from that session:
q-a-graphic
Can you discuss the flexural strengthening for reinforced masonry walls?
Out-of-plane flexural strengthening can be provided with FRP on the required face of wall. In-plane (or shear wall type) flexural strengthening can also be provided with vertical FRP strips near the ends of walls.
In general, by what percentage can FRP solutions increase the strength of existing concrete shearwalls?
This really depends on the existing wall, but we have seen strength increases of 22% in our testing of one layer of glass fabric installed on 8″ thick ungrouted CMU shearwall.
How does FRP compete in terms of cost? It seems like a cost-prohibitive solution compared to other remediation techniques in the absence of other limiting factors (space limitations, etc.).
FRP may be expensive on a cost/SF basis. However, if you compare it with the materials and labor involved in section enlargement or demolishing parts of buildings, it becomes cost effective. FRP installations are also not unsightly like bolted steel plates or wide flange members slung under concrete slabs/beams.
Who designs the FRP system: Simpson Strong-Tie or the Structural Designer?
The Simpson Strong-Tie Engineering Services group provides the FRP design on most projects, but we have also worked with the engineer on record (EOR) to check their FRP design on projects.
Are there any deformation compatibility issues between carbon fiber or glass and existing reinforcing bar that need to be accounted for in design? Is long-term creep similar to that seen with reinforcing bar?
CFRP and GFRP have different elastic moduli from each other and from steel. When designing an FRP strengthening solution, these differences must be taken into account. For flexural applications, the FRP should be designed to fail from debonding after the internal rebar begins to yield. Creep is taken into account in design equations through reduction factors and stress checks.
Will ACI 440 be updated to include the use of FRP with post-tensioned beams (i.e., unbonded tendons)? Does Simpson Strong-Tie do all stress checks based on gross section properties when total stress is < 12sqrtf’c?
Yes, there is an ACI 440 committee working on including an unbonded PT section in ACI 440.2R. We will work with the EOR to determine what section properties are most appropriate for the specific member being evaluated.
Can you increase deflection limits with FRP?
While FRP does help to limit deflection in members, members with deflection issues are not typically candidates for FRP repair. Prestressed laminates as used in Europe would be a better solution for a member with deflection issues. We do not currently offer prestressed laminates but may in the future.
Does an aesthetic coating interfere with bridge inspection? What is inspection looking for? Delamination or other defects?
A coating could interfere with a visual inspection of the FRP surface. A visual inspection can reveal changes in color, debonding, peeling, blistering, cracking, crazing, deflections, indications of reinforcing-bar corrosion, and other anomalies. In addition, ultrasonic, acoustic sounding (hammer tap) and thermographic tests may indicate signs of progressive delamination. ACI 440 and AC 178 have extensive special inspection recommendations.

Learn more: Webinar – Introducing Fabric-Reinforced Cementitious Matrix (FRCM)

In this free webinar we dive into some very important considerations including the latest industry standards, material properties and key governing limits when designing with FRCM.
Continuing education credits will be offered for this webinar.
Participants can earn one professional development hour (PDH) or 0.1 continuing education unit (CEU).

For complete information regarding specific products suitable to your unique situation or condition, please visit strongtie.com/css or call your local Simpson Strong-Tie RPS specialist at (800) 999-5099.