Moisture-related floor covering and coating failures are a very costly and disruptive issue with the direct and in-direct costs associated with such issues estimated to be in the hundreds of millions of dollars each year in the United States alone. In this session, a brief overview of the previous sessions will be provided and experts in the field of slab moisture, concrete, testing and forensics will answer your industry questions related to the subject.
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 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.
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.
On August 9, 2019, Tyson Foods' Holcomb, Kansas beef plant experienced the first large fire in the meat processing industry in nearly 20 years. The long-burning fire precipitated the collapse of a portion of the high roof over the mechanical mezzanine, which housed equipment for numerous critical plant processes. This took portions of the plant, the second largest in the United States, out of operation for months. The pressures of substantial business interruption costs, as well as the market consequences for cattle feeders from the Southern Plains region, necessitated a rapid response. This presentation highlights the investigation into the extent of damage to precast members, including visual inspection, nondestructive and laboratory evaluations, testing, simulation, and analyses. Based on this investigation, members were identified for repair or removal and replacement.
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.
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...