Repairing and extending the service life of concrete in severe environments first requires that one understands what may be considered severe why it may be considered so. This presentation will discuss the ways in which different organizations and technical committees around the world define ‘severe environments’ for concrete structures; types of deterioration mechanisms and materials-related distress that may severely and quickly deteriorate concrete, type of structures with potentially severe environments, and U.S. geographical considerations.
A significant percentage of repairs are performed during the course of constructing new structures. Once a construction anomaly or error occurs the first concerns are for life safety and schedule impact. A review of the steps necessary to successfully perform repairs and minimize impacts to the ongoing construction. Examples of challenging problems and the traditional and non-traditional solutions to these problems will be discussed.
High Traffic Commercial/Light Industrial applications including light manufacturing, warehouse/big-box stores and high traffic retail applications present their own unique challenges in concrete repair. This presentation will review concrete repair options that a focused on those application that may require both fast application/turnaround time and strength/use durability for forklifts and trucks. High Traffic Commercial/Light Industrial applications including light manufacturing, warehouse/big-box stores and high traffic retail applications present their own unique challenges in concrete repair. This presentation will review concrete repair options that a focused on those application that may require both fast application/turnaround time and strength/use durability for forklifts and trucks. While there are many option for quick repair that can be open to use in a matter of hours, it is important to acknowledge he potential limitations of these options over the long term.
Due to improper design or implementation sometimes Part of the New projects are re-executed or repaired. Islamabad - Rawalpindi BRTS (Bus Rapid transit System) Consisted of 20 Stations Covering around 23 km path connecting twin cities. Each station Roof Consisted of ACP Sheets Fixed on Aluminum Frame with Steel supports. The joints of ACP sheets were filled by Silicon but improper materiel and workmanship caused leakage in joints. Total length of joints was over 400,000 RFT. Leakage was invariably from almost every area.
A follow-on presentation to the discussion of our evaluation of over 1500 tire and lube facilities across the United States that prescribed immediate repairs where necessary, reinforcement where deterioration reduced capacity below acceptable levels and coatings necessary to protect structural steel and structural concrete (i.e. our 2019 Philadelphia presentation). This will be an in-depth presentation of how repairs were specified for (3) specific types of structures. The (3) structure types are exposed structural concrete, composite metal deck and fully reinforced form deck slabs all supported by steel structures and reinforced concrete walls. Presentation will include before, during and completion photos of each project discussed. Again, touch on the evaluation processes to include demand to capacity ratios review, evaluation system and inspection form, triggers to determine when shoring is necessary, calculation of capacities per AISC 360, ACI 318, ACI 562 and local building codes.
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.
What happens when a building owner calls with leaks into a building they just finished? After verifying whether they want to file a lawsuit or not, the course of action is important. An investigation and preliminary testing are typically recommended to understand the original design and the quality and consistency of the construction. Design of remedial repairs and a pilot repair program followed by retesting to confirm results. How extensive are the failures and how invasive do the repairs need to be? Costs? What materials were used and were they compatible? Public perception and developer/owner reputation are important. The occupants have just moved in. Higher expectation of successful repairs. Can we involve the original design and construction team? These are just a few of the issues that need to be faced early in this process. One must communicate often and clearly with the owner and rest of the project team in order to manage expectations, costs and construction quality control.
Dallas City Hall and Plaza are recognized by many due to the opening scenes of Dallas, the television show. What is less known is that the structure is a significant early example of bonded post-tensioned concrete which was utilized throughout the superstructure and two-story parking garage constructed beneath the plaza. Opened in 1977, the parking garage is a two-way bonded post-tensioned concrete slab with unreinforced drop panels supported by flared circular concrete columns. The garage covers two city blocks, extends under two adjacent multi-lane streets, and supports mature landscaping, pool, fountain, and up to 11’-0” of soil. In 2017, several square feet of a drop panel fell from the structure and subsequent observations found multiple locations of drop panel and column capital failures. A structural investigation including destructive and non-destructive testing, and analysis of the existing structure was undertaken to determine the cause of the failures.
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.
Outlines the steps in preparing concrete for replacement material in areas where corroded reinforcing steel has caused cracking, spalling, delamination, or other types of deterioration. Topics covered include exposing and undercutting reinforcing steel, edge and surface conditioning, repair of reinforcing steel, and removal geometry.