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.
Since the invention and introduction of Portland cement-based, self-leveling underlayments in the U.S. in 1978, sub-floor preparation technologies, means and methods have continuously evolved. This evolution has been driven by dynamic market forces, including more manufacturers, a larger and more experienced installer base, increased adoption rates with a wider range of applications, ever-increasing project sizes and complexity, new flooring structures with more demanding requirements, the ability to handle high moisture levels with less surface preparation and fast track construction.
Construction errors such as the misplacement of reinforcing steel and modifications like the addition of openings traditionally required intrusive repair methods. The addition of structural steel support or enlargement of the concrete elements is often not aesthetically pleasing or practical and the cost and time impacts are onerous. FRP strengthening solutions are non-intrusive, practical, and can be implemented quickly without major impact on the other building trades. The presentation will guide the audience through the feasibility assessment of FRP strengthening and implementation of the strengthening solution. The roles of the various parties, including the Engineer of Record, the FRP Design Engineer, the General Contractor, the Structural Contractor, and the FRP Installer, will be illustrated. Photographs of completed repairs will be presented.
Nondestructive testing is often used in conjunction with traditional methods to assess construction, material, or structural deficiencies in new construction. This presentation describes evaluation of unique delamination failures within below-grade, exterior walls of a new subway station. The walls were conventionally reinforced mass concrete cast against a soldier pile and lagging retention system. Shortly after construction, leakage at cracks and joints was observed and injection processes led to delamination of the interior surfaces. The assessment objectives were to determine the extent and cause of near-surface discontinuities and evaluate the structural integrity of the walls. Nondestructive testing included flaw detection using Impulse Response [structural mobility testing] and reinforcement locating using ground-penetrating radar. Sampling and petrographic examinations were conducted to correlate test results with distress conditions and evaluate the in-situ concrete.
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.
This presentation will look at how technology is used to perform condition assessments at height and in places with difficult access utilizing a virtual toolbox that includes a wide range of instruments and tools for non-destructive evaluation and testing, and a fleet of drones, each of which has a different use. The presentation will discuss how to use drones and tools at height; how the industry is using drones in new ways; and how some municipalities are changing policies to adapt, especially with regard to facade inspections.
From the days of boiled Linseed oil, to the discovery of membrane forming cures, to the development of carbon dioxide injection; curing has evolved to accommodate the demands of the construction industry. This presentation will look back at the early standards developed by ASTM, contrasting them to the standards that are currently under consideration. There are many ways to cure concrete, this presentation will review the various product options framed in the context of weather. Lastly, the presentation will explore the various methods discussing the features and benefits of the common curing practices of today.
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.
The mitigation of moisture in concrete floor slabs has become an entire sub-industry to the placement of concrete floor slabs that will receive a moisture-sensitive floor covering or coating. In this webinar, attendees will learn what approaches are being used to mitigate an unacceptably high level of moisture in a concrete floor slab and what pre-installation evaluation procedures are necessary to help ensure the success of a moisture mitigation strategy.