Two projects will be explored in this presentation. The first is a concrete structure which for 20 years was exposed to extreme heat. The second is a structure which was exposed to extreme vibrations. Both these structures were integral parts of manufacturing processes and required limited down time to repair. The questions needing to be answered were: what is the condition of the existing concrete and what are the repair options for these structures. We turned to non-destructive techniques to evaluate these structures. Non-destructive techniques can provide insight into structures when accompanied by experienced engineers and petrographic analysis. Repair options were provided at the end of our evaluation leading to reduced down time and well-planned repairs.
The case-histories based presentation will focus on the use of nondestructive evaluation (NDE) methods to detect flaws and damage in concrete construction. Case histories will be presented for detection and mapping of flaws and damage in concrete such as cracking, delamination, honeycomb, void, corrosion, fire damage, alkali-silica reaction and low strength concrete. The case histories for the concrete structures are anticipated to include parking structures, bridges, buildings and dams. NDE methods will include sonic/ultrasonic, infrared thermography, radar and corrosion technologies where the results in many cases were confirmed by coring. The use of some of the NDE methods for QA of concrete repairs such as epoxy injection and patching will also be discussed.
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.
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 the most widely used construction material and can be durable for hundreds of years; however, the main cause of concrete deterioration is from corrosion of reinforcing steel. Steel is thermodynamically unstable and will eventually oxidize to a lower energy state. The rate of deterioration in new and existing structures can be modeled to predict the service life based on the severity of the service environment, the concrete quality, the ingress of deleterious materials, and other factors to various degrees of success. This presentation will provide an overview of many of the service life models currently in use and provide an evaluation protocol for their application related to both new and existing structures.
Matching concrete sounds simple, but there are many factors that affect color, texture, and aesthetics. There is often a challenge with using modern cementitious materials for matching older and historically manufactured cements. Whether your project is historic or contemporary, this presentation will outline materials and methodology that are important to understand when concrete matching is important. With many mid-century buildings coming of repair age, this is a critical time for understanding these concepts. The presentation will include the fundamentals of concrete materials, how cementitious materials affect concrete color, how to use color measurement technology in developing a color match mix design, how aggregate exposure affects aesthetic perception, and other helpful tips when it comes to matching concrete for durable and aesthetic results. Regionally available materials will vary, but the methodology for color matching durable repairs is fundamentally the same.
Industry questions related to moisture-related floor covering and coating failures will be answered by the presenter during a 1-hour webinar. Questions will come from ICRI members through a survey conducted prior to the webinar and PPT slides addressing the questions prepared by the presenter. Questions from webinar attendees will also be answered during the webinar.
The presentation, through case studies, talks about emergency response services for structural issues encountered during construction of new design projects. Among other examples is an eleven story precast parking structure. The contractor observed significant diagonal faulted cracking of L-beams (supporting double-tee sections) near bearing locations, few days after pouring topping slab. In addition, inverted-tee girders were observed to be supported on cracked corbels at other locations. A quick turn around was required to mitigate any immediate life safety hazard posed by the structural distresses and buy time for thorough investigation, non-destructive testing, analyses, and repair design. Another example is a seven story precast parking structure. The structure was under construction and reportedly erected out of plumb. Poor concrete placing practices and poor weld detailing led to widespread cracking in multiple structural elements throughout the structure...
Dealing with water is always a challenge when constructing a new structure. Whether it is water infiltration that was expected, or water manages to circumvent pre-planned waterproofing methods, it can wreak havoc on the building and interfere with construction schedules. The term “belt and suspenders” is often used in waterproofing and there is a good reason for it. Water chooses the path of least resistance, and many times that path is not discovered until it is too late. There are many methods of water control that can be implemented before, during and after a structure is completed. This presentation will focus on water control methods for new construction that can be implemented during or after the construction process.
Increasingly, the Construction Industry is being dramatically impacted globally by internal and external forces. These influences range from acute labor and skill shortages, demographic and urbanization shifts, as well as, the Industry’s conversion from analog-based processes to digital workflows. This presentation will overview ten significant trends which are uniquely affecting the Construction Industry, creating both new challenges and opportunities, while transforming the Construction Industry.