- Presenters:
- Dr. Farhad Habibi, PhD | Justin Breg, PhD
- Duration:
- 36 Minutes
- Format:
- Audio and Video
- License:
- Access for 6 month(s) after purchase.
- Short Description:
- Alkali-Silica Reaction (ASR) can cause significant damage to concrete structures including bridges, roadways, airport runways, and nuclear power plants. When reactive aggregates are included in a mix, the presence of moisture initiates a reaction between the alkaline cement paste and reactive amorphous silica. The result is a gel that continues to dilate, which may cause cracks in the concrete mass. A research program was undertaken at the University of Toronto to investigate the effects of ASR on large-scale and small-scale concrete specimens. Several specimens were constructed using reactive (ASR) concrete and non-reactive (regular) concrete, and their short-term and long-term structural and mechanical behavior were compared. In this presentation, we will discuss the results of the research program, will offer best practices to minimize the risk of ASR in concrete during placement, and will propose several strategies for repair of structures that have been degraded due to ASR.
- Price:
- $15.00 - $25.00
- Presenters:
- Robert M Cordova | Mr. Richard First
- Duration:
- 30 Minutes
- Format:
- Audio and Video
- License:
- Access for 6 month(s) after purchase.
- Short Description:
- The Ituango dam is an embankment dam that is currently under construction on the Cauca River in Colombia. The largest hydroelectric power plant in Colombia’s history. Three large diversion tunnels used to divert the water from the river around the construction site during construction collapsed as a result of heavy rainfalls. The nearly completed pump house had to be flooded to accommodate premature water build-up in the reservoir. These tunnels would need to be permanently sealed. “Pre-stoppers” would need to be constructed in place to serve as bulk heads between which would ultimately be excavated and back-filled with concrete to permanently seal the tunnels. Additional to standard anti-washout properties, the grout had to withstand swiftly flowing water and exhibit an extended working time at temperatures above 32 degrees C. A custom grout was developed for this application. In the end, hundreds of grout micropiles were tremied, consuming more than 1,650 tons of grout, to produce...
- Price:
- $15.00 - $25.00
- Presenters:
- Eric Williams
- Duration:
- 25 Minutes
- Format:
- Audio and Video
- License:
- Access for 6 month(s) after purchase.
- Short Description:
- Presentation will discuss Vision 2020 (Development, Successes and Challenges) as well as items which still need to be completed. This portion of the presentation will be followed by an overview of the presenter's perspective on the future needs for the concrete repair industry. All attendees will be invited to participate in a workshop to develop a complete list of industry needs (consensus if possible).
- Price:
- $0.00 - Base Price
- Presenters:
- Stephen Lucy
- Duration:
- 49 Minutes
- Format:
- Audio and Video
- License:
- Access for 6 month(s) after purchase.
- Short Description:
- 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.
- Price:
- $15.00 - $25.00
- Presenters:
- Dr. Ali Abu Yousef | Michael Ahern
- Duration:
- 47 Minutes
- Format:
- Audio and Video
- License:
- Access for 6 month(s) after purchase.
- Short Description:
- After only six years of service, a 6-foot long narrow piece of concrete spalled off an exposed slab edge of a 680-foot tall high-rise in Texas, and fell 160 feet to the podium below. The spall was attributed to premature corrosion at the drip edge. The building featured approximately 9,200 feet of exposed slab edge over its height. Given the potential risk to safety and property of additional concrete spalls, the Owner requested forensic investigations, which (1) identified other areas with signs of similar distress and (2) determined the underlying problem of low reinforcement cover at the drip edge was pervasive. In response, repair options were developed to address the problem and restore intended durability. Given the building height, difficult exterior-only access, downtown environment, and post-tensioning anchors along the slab edge, the repair design and construction both had unique challenges to consider and overcome.
- Price:
- $15.00 - $25.00
- Presenters:
- Mr. Peter Craig
- Duration:
- 1 hour
- Format:
- Audio and Video
- License:
- Short Description:
- Moisture coming from, or through a concrete floor slab, can lead to conditions that are damaging to floor coverings, coatings, the building’s environment, and the ability to store moisture sensitive products directly on a floor slab. In this webinar, attendees will learn where potentially damaging levels of moisture come from, how moisture migrates, and what design measures are an absolute necessity to minimize the risk of moisture-related problems.
- Price:
- $10.00 - $40.00
- Presenters:
- Scott Michael Tarr
- Duration:
- 1 hour
- Format:
- Audio and Video
- License:
- Short Description:
- Concrete is one of the most versatile building materials in the world and can produce floor slabs that provide an excellent platform for floor coverings and coatings. Water is an essential component of every concrete mixture. Without it, concrete is not workable and finishable. If water is not used, the cement in the mixture cannot hydrate and gain the required strength. However, once placement, finishing, and curing is complete, remaining moisture in the concrete can adversely affect the installation of flooring materials and the behavior of the slab itself. This webinar will discuss the importance of water in a concrete mixture and review a few concrete problems that water can cause, such as shrinkage, curling, ASR, delamination, dusting, and scaling. In addition, attendees will learn the design and construction considerations that can be used to minimize the potentially adverse effects of moisture in concrete.
- Price:
- $10.00 - $40.00
- Presenters:
- Erik Villari | Mr. Michael Salera
- Duration:
- 45 Minutes
- Format:
- Audio and Video
- License:
- Short Description:
- Using Unmanned Aerial Vehicles and Systems (aka UAVs aka Drones) continues to be a hot topic for engineers and designers. Within the past 10 years, we have seen technology change how we live, work, play and learn. These advances in technology have enabled humans to be more efficient as well as socially and environmentally conscious and connected. Advances in engineering technology and efficiency have expanded structural engineer’s roles in inspection services. This presentation will highlight drone utilization for exterior surveys and inspection, impact on the built environment, and how drones will continue to influence in the future. This includes areas that are too dangerous for humans or structures where rigging can be difficult or impossible as well as the cost benefits of using a drone. The presentation will also delve into the effectiveness and appropriate applications of drone usage, specifically for hands-on applications.
- Price:
- $15.00 - $25.00
- Presenters:
- Hamed Layssi
- Duration:
- 45 Minutes
- Format:
- Audio and Video
- License:
- Short Description:
- 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.
- Price:
- $15.00 - $25.00
- Presenters:
- Ms. Stacia Van Zetten
- Duration:
- 45 Minutes
- Format:
- Audio and Video
- License:
- Short Description:
- The general sentiment around construction and modern technology is that the industry has been slow to embrace it. While this is true of the past, the current and future construction industry is all about modern technology. Not only does technology help to make the industry safer (something that has been a struggle for a very long time), but it is helping contractors to take back control of their budgets, to make smarter choices about project planning and equipment and is, consequently, pushing the green-construction trend forward. The purpose of this presentation is to provide a summary on the current technologies being used in the construction industry with a focus on concrete and to dig even further as to how these can be applied to repair projects. It will provide case studies on how using technology to bring ambient and concrete temperature, relative humidity and strength (among other) data online can help contractors be more efficient.
- Price:
- $15.00 - $25.00
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