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Although the analysis and upgrade of concrete structures is somewhat of a “scientific art” that has been practiced for many years it has evolved into a complex science that requires a blend of engineering, material science and construction perspectives. Strengthening projects may utilize traditional materials such as conventional cement-based and steel materials as well as advanced composite materials (FRP’s) that are commonly used for aerospace applications. The techniques used to design and install these materials for upgrade applications are not common to the engineering and general construction industry which can make strengthening projects even more challenging and complex than new construction. 

There are many factors that create the need for strengthening. They include construction and design errors, increase in live load, new code requirements, low concrete strength, voids created during concrete placement, new penetrations and prevention of progressive collapse from blast loads. 

This presentation will describe the solution strategies, different techniques, materials and design concepts used for upgrading concrete structures. The use of each technique will be illustrated through actual case studies. 

Factors affecting the performance or capacity of reinforced concrete 

• New Loads- change in use 
• Construction or design errors 
• Missing, misplaced or damaged reinforcement 
• Voids or Honeycombs created during concrete placement 
• Cutting of new penetrations that affect existing reinforcement 
• Low strength concrete 
  
  

Strengthening with externally bonded FRP systems 

• Typically used forms 
• Installation techniques and QA/QC 
• FRP Limitations and strengthening limits 
  

Conventional strengthening techniques for cases where FRP is not viable 

• External and Internal Post Tensioning 
• Section enlargement and bonded overlays 
• Supplemental steel supports and span shortening 
  
  

Case studies to cover various types of projects that will display the strengthening of both new and old structures including two designed by Frank Lloyd Wright- Fallingwater and the Guggenheim in NYC. 

The presenter, Mike Larsen, is a Senior Business Development Manager at Structural Technologies, a STRUCTURAL Group Company- a $400M specialty design/build repair contractor. Mike has 12 years of experience within the repair and strengthening of commercial, industrial and underground structures, which includes Estimating, Operations Management (P&L) and Business Development. He has a total of 36 years of general construction experience in vertical and horizontal construction projects and pipeline condition assessment. Mike is a retired Master Sergeant from the United States Air Force, which he served for 23 years within the Civil Engineering Combat Engineers where he served in South Korea, Panama, Germany, Saudi Arabia and United Arab Emirates. Mike earned two Associates Degrees from the USAF (Biological Ecological Controls & Construction Management). Mike has presented numerous times to the Structural Engineers Association, ASCE, AWWA, ACI and other organizations. His operations and construction background combined with engineering demonstration tools offer the ability to communicate technical issues that directly relate to engineers and contractors. 

Brian R. Barth is the district engineer for the Fort Worth District of the Texas Department of Transportation (TxDOT). He oversees the planning, designing, building, operation and maintenance of the state transportation system for the district which comprises nine counties: Erath, Hood, Jack, Johnson, Palo Pinto, Parker, Somervell, Tarrant and Wise. The Fort Worth District has the state’s third highest population and number of registered vehicles.

A 27-year member of the TxDOT family, Barth began his career as an engineering assistant in the Dallas District after graduation from the University of Texas at Austin with a bachelor’s degree in civil engineering. In 2003, Barth was appointed as the Dallas District’s director of transportation planning and development. From 2009 to 2013, Barth served as the Fort Worth District’s deputy district engineer, providing joint oversight and development of the DFW Connector, North Tarrant Express, I-35W, I-30, and Chisholm Trail Parkway.

While implementing $5 billion in public-private partnerships, Barth worked with the Texas Association of Metropolitan Planning Organizations (TEMPO) to forecast future revenues for transportation over the next two decades. In 2013, Barth oversaw a statewide initiative to streamline the procurement of professional engineering services in an effort to help TxDOT deliver the most transparent and cost-effective projects.

Appointed as Fort Worth district engineer in November 2013, Barth serves on the Regional Transportation Council of the North Central Texas Council of Governments working to solve Metroplex-area transportation issues. Under Barth’s direction as district engineer, he also oversees over $1 billion in construction work each year in addition to major projects on I-35W, SH 360 South, and the I-30/SH 360 Interchange.

A sports enthusiast, Barth is a devoted fan of the Texas Longhorns, Dallas Cowboys, Texas Rangers, and Dallas Mavericks in addition to playing intramural basketball and softball. He and his wife, Brenda, are happily married and live in Flower Mound with their daughter, Brianna.

 
A brief overlook of the development, fabrication, and utilization of TxDOT’s second generation overhang panel.

Kevin Moyer, PE, MSE, is a Transportation Engineer in the Bridge Division of the Texas Department of Transportation. He is a retired Army Sergeant First Class with 21 years of Reserve and Active Duty service. He obtained a BSCE and MSE (Structural Engineering) from The University of Texas at Austin. He has four years of service with the Texas Department of Transportation Bridge Division and 15+ years of service in the construction industry. Kevin is the father of three great kids and husband to a wonderful wife.