The ACI 562-16 Repair Code is primarily intended for the Licensed Design Professional for providing the requirements necessary for assessing and designing repairs and rehabilitation of existing concrete structures.
In June 2016, ACI published ACI 562-16,” Code Requirements for Assessment, Repair and Rehabilitation of Existing Concrete Structures and Commentary”. ACI 562-16 replaces ACI 562-13 as a standard for the repair of existing concrete structures. Significant changes to ACI 562-16 include improvements in terminology for consistency with ISO, ASCE and other documents, inclusion of requirements for level of repair based upon extent of damage present, and revisions to the interface bond provisions. The video will describe the concrete repair code, focusing on key changes made to the code and describe how the code is to be used on concrete repair projects.
The application of nondestructive testing and evaluation for detecting existing defects and anomalies in concrete structures will be presented. Proper inspection and assessment is an integral part of a successful repair and rehabilitation. A well-defined inspection will help asset owners and their consultants in identifying the location and extent of existing defects, and enabling them in selecting proper repair materials and optimizing the area that needs rehabilitation. Moreover, NDT methods can help identify potential defects that are not visible to the naked eye, such as early-stage delamination, corrosion, and other durability related issues. In this presentation, several cases in Canada will be demonstrated, where the results of nondestructive testing and evaluation have been used to help consultants and contractors with cost-effective and reliable repair planning. Applications of ground penetrating radar, ultrasonic pulse echo tomography, seismic tomography, will be discussed.
Arrowhead Stadium originally opened in 1972 and is known to be the home to the Super Bowl Champions Kansas City Chiefs. Renovations of the stadium completed in 2010 included adding luxury suites on the club level of the stadium. This meant that the upper seating bowl not only had to seat more than 34,000 Chief fans but also act as a "roof" for the new luxury suites. The upper seating bowl comprises L-shaped precast concrete seating risers spanning from cast-in-place concrete raker beams and is divided by sixteen expansion joints. In 2018, the planning for the upper seating bowl waterproofing program began. The goal for the repair project was to implement waterproofing upgrades to protect the concrete for the next 10 years. To add to the challenge of a large-scale waterproofing and structural repair project, the construction efforts had to include coordination with simultaneous seat replacement to be completed in a single off-season.
This presentation aims at providing clear and down to earth definitions of what Post-Tensioning systems are, the different repair strategies related to these systems, and critical factors to be accounted for during the design and execution of any intervention on a Post-Tensioning slab.
Arlington Memorial Bridge is a reinforced concrete spandrel arch bridge that connects Washington, DC and Virginia across the Potomac River. After over 85 years in service, the bridge started exhibiting signs of deterioration, including reinforcement corrosion. As part of a major rehabilitation effort to extend the bridge’s service life, targeted cathodic protection (CP) systems were installed in the arch cross-walls, floors, and under arches to mitigate and prevent corrosion. The implemented CP system consisted of galvanic and two-stage anodes to mitigate corrosion. Galvanic anodes were installed in the repair areas to prevent the ring anode affect and ensure a durable concrete repair. The two-stage anodes were installed in areas of concrete which were actively corroding without signs of concrete deterioration.
Concrete placement and finishing defects raised by a member of the project team may indicate a greater (unobserved) structural concern, a long-term durability issue, or simply an aesthetic problem. Concrete defects can delay the project schedule, require costly investigation fees, and necessitate removal and replacement. This presentation is intended to tackle concrete placement and finishing defects faced by the concrete construction industry. Topics will include: cold joints, delaminations, dusting, honeycombing, form leakage, plastic shrinkage cracking, floor flatness/levelness, in addition to others. This presentation will discuss the causes of these concrete defects, techniques for evaluating various defects, and approaches for mitigating these problems. Attendees will be introduced to various evaluation methods (e.g., impact-echo, ultrasonic pulse velocity, ground penetrating radar, concrete coring, petrographic examination, etc.) and when their use is appropriate.
In this presentation, we will address the effect that corrosion has on our concrete infrastructure, including buildings, bridges, sea walls, cooling towers, docks, and many other reinforced concrete structures.