Date: November 18th, 2014
Structure: One story family, residence/occupied.
Contractor: The Basement Guys, Columbus, Ohio.
Material used: Rhino 8′ carbon fiber reinforcement strap, Rhino bracket, Rhino epoxy.
Project Scope: 11 course high un-reinforced 12″ cement block basement foundation wall failure. The homework had a crawlspace that had a poorly built footer causing the weight of the home above the crawlspace to be transferred to the connecting basement wall. This resulted in a cracked corner that was separating.
Solution: Install Rhino Carbon Fiber corner repair all repairs were installed on every other course and ran 5′ past the corner in both directions.
Observations: The corner is now tied together which evenly distributes the pressure eliminating any future damage.
Date: October 30th, 2014
Structure: One story family residence/occupied
Contractor: Martinez Renovations Columbus, Ohio
Material used: (12) custom cut 3′ 5.5″ Rhino Carbon Fiber straps, 5 tubes of Rhino Epoxy and 12 Rhino brackets.
Project Scope: 5 courage high un-reinforced 12″ cement block crawlspace foundation wall failure. The homeowners built an addition that was not properly supported when built. This caused the new foundation walls to bow and pull the connecting basement wall to bow as well.
Solution: Install 12 Rhino Carbon Fiber reinforcement straps every 4′ on center. All repairs were attached at the sill plate with the Rhino Sill Plate as well as pinned to the footer with the Rhino pin.
Observations: The crawlspace addition is now properly reinforced and the homeowners no longer have to worry about damage being done to the existing basement walls that are attached to the crawlspace.
Project Description: This is an inspection and recommendations for collapse of the basement wall at the Applegett Residence located at 6506 Purplefinch Court, Westerville, Ohio 43081. This property is Franklin County Parcel ID # 110-005290-00. The residence has a concrete masonry unit (CMU) block foundation wall that form the basement for the structure. The house is approximately 1,238 square feet with an attached garage.
Findings: There was a collapse of the basement wall for approximately 14’ along the center section of the south east wall of the building. This inspection was performed on June 26, 2014. The collapse occurred on June 19, 2014. There was carbon fiber repairs on this wall at 5’ O.C. My understanding is that these carbon fiber repairs were performed in 2004 and were a product called Fortress Carbon Fiber.
Conclusions: The Carbon Fiber reinforcement strips did stiffen the wall and prevented it from bowing into the basement. However, by stiffening the wall and preventing the wall from bowing the outside load caused the CMU wall to fail in shear at the bottom of the wall. This caused the bottom of the wall to dislocate.
It is my opinion that was Carbon Fiber reinforcement strip design failed to provide an attachment at the base and top of the wall to prevent the dislocation caused by the outside shear forces.
Recommendations: It is recommended that basement wall be rebuilt with concrete masonry units as shown of attached sheets.
It is also recommended that the basement wall be reinforced with the Rhino System carbon fiber reinforcements at 3’O.C. on the side wall where the CMU blocks were replaced as well as one carbon reinforcement strip on each of the front and back walls 2’ from corners. New carbon fiber reinforcements shall be anchored at the top and bottom to prevent shear dislocation. The Rhino carbon fiber reinforcement system is recommended.
As Rhino Products works on getting our products into the commercial market, it is important develop relationships and educate employees of engineering firms and government officials. Our In-house engineer previously worked 13 years on projects with the Ohio Department of Transportation, City of Columbus, AEP, and multiple engineering firms with his main focus on Bridge Projects. In bridge construction, due to schedule restraints and the fast paced nature of the work, beam flexure tests are used quite often to verify that newly poured concrete has reached sufficient strength to support the necessary construction loads prior to full cure.
We obtained a beam that had been broken twice from a local project and pulled it back together with a ratchet strap. We then laminated the top of the beam with our unidirectional carbon fiber. Once the epoxy was cured we met with ODOT to perform the same flexural test on the beam that broke it originally. The flexural test was performed with the load at the location of the prior break and taken up to 650psi, the strength required to proceed with loading newly poured concrete on ODOT projects. The concrete had gained strength but this strength gain was irrelevant because the beam was already broken.
The test was then taken up to around 935 psi and still did not break. This test was performed over both of the prior breaks and the carbon fiber did not fail.
Since the concrete was already broken at the test locations, the flexural resistance that we saw was solely the strength of the carbon fiber and its bond to the concrete.
This test illustrates the usefulness of carbon fiber in repairs and also in strengthening. For more information on the uses of carbon fiber on commercial projects and to find out how carbon fiber could be a benefit on your projects, please contact our in house Ohio licensed professional engineer.
On a newly constructed high rise in downtown Nashville, engineers had concerns with cold joints at the top of an exterior wall.
The engineers directed the general contractor to epoxy inject these joints. While quoting this work, Derek Veselich, owner of Ground Up Builders, Inc. recommended that carbon fiber be used in conjunction with the epoxy injection. The engineers liked the idea so Derek contacted Rhino to discuss the best carbon fiber option.
It was determined that the 12” Rhino Carbon Fiber crack repair be used. The horizontal tow was chosen to provide strength across the crack and help hold the two sections of the wall together.
The carbon fiber and epoxy were installed prior to the injection in order to seal the crack then the ports were installed through the carbon fiber. This required drilling through the carbon fiber but since the horizontal tow was used, this did not compromise the integrity of the repair.
Rhino was able to send out the carbon fiber along with our epoxy injection kits overnight for Ground Up to begin the repairs the following day. There were also cracks in the newly constructed pool on top of the building that Ground Up looked at with the general contractor. They were able to use the same repair method that was used on the cold joints to address these cracks.
We want to say thank you to Ground Up Builders, Inc. for recommending our products. They recently attended our first Day of Rhino in Columbus, OH which offered live demonstrations with tips and tricks on installation, marketing, lead generation, and sales training as well as installation examples and product overviews.
If you come across a situation on any of the projects you are working on where you think carbon fiber could be used, give us a call and we would be glad to work with you to come up with a solution. Our in-house Engineer can also work with your engineers to answer any questions they may have. We will be having future meetings like the Day of Rhino and are always available to answer questions and provide training when necessary.
Download:Concrete Slab Repair
Cracks and movement in slabs can be very problematic, especially when covered with surfaces like tile or hardwood that cannot handle this movement.
Download:Increasing Wall bending capacity
A general contractor contacted Rhino Products, Inc. after Carbon Fiber Reinforced Polymer (CFRP) was specified on one of their projects. The CFRP was being added as a repair method for a wall that was poured without all of the per plan rebar installed.The contractor had placed the vertical dowels in the wrong location outside of the limits of the pour. They had also left out a portion of the vertical reinforcing steel.
Download:Block Wall Corner Repair
Carbon fiber is one of the most versatile and best solutions for crack repair on block walls. If the joint is re-tucked or patched, it is likely that the crack will reopen. When carbon fiber is used, the bond strength over the crack provides much greater strength to hold the crack together than repairing the joint alone. Even if there is still slight movement it the joint, the carbon fiber will resist this movement and remain intact.In some cases, rather than more expensive repairs that involve excavation and foundation stabilization, carbon fiber can be used for a permanent crack repair solution.
Download:Salt barn wall failure repairs
After a winter with below average snowfall, the City of Cambridge, Ohio was left with an excess of road salt on hand. Due to their salt contract obligations, they were required to take on additional quantities of salt the following year in preparation for the
upcoming winter. This left their main salt storage barn over full and resulted in damage to the structure.