ACR Concrete Controversy Continues – Investigation Indicates that ASR is to Blame

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  • 6:35PM Dec 04, 2013
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Query: Can the main mechanism of concrete distress and cracking in a concrete made with ACR-susceptible aggregates be caused by ASR?? Fact: Alkali Carbonate Reaction (ACR) results when brucite, formed in concrete made with dolomitic (ACR-susceptible) aggregate, crystallizes and expands. Fact: Alkali Silica Reaction (ASR) occurs over time when the alkalis in cement react with […]

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Webinar: Material Challenges in Maintaining Aging Infrastructure – Reinforced Concrete Structures

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  • 12:03PM Nov 20, 2013
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According to the 2013 Report Card published by the American Society of Civil Engineers (ASCE), one in nine bridges in the United States is structurally deficient. Tight budgets require efficiencies when selecting work to be done and so priority is often given to those tasks that will make these structures last as long as possible. […]

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Game Changing Regulation for Respirable Crystalline Silica? New Industries and New Challenges

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  • 9:23AM Sep 16, 2013
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OSHA has proposed new standards for respirable crystalline silica exposure and a new uniform airborne permissible exposure limit (PEL), calculated as an eight-hour time-weighted average. The agency has identified 25 industry subsectors encompassing approximately 130 industrial and maritime operations in which exposure to respirable crystalline silica is common during operations such as cutting and grinding […]

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Materials Science Bridges the Gap between Catastrophic Event and its Root Cause

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  • 12:58PM Jul 25, 2013
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Notable catastrophic bridge collapses in Minneapolis and Washington State have garnered public attention related to the structural integrity of many of the nation’s bridges. More cause for concern is the 2013 Report Card published by the American Society of Civil Engineers which states that one in nine bridges in the United States is structurally deficient. […]

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Failure Analysis Determines Faulty Workmanship, Not Defective Building Materials, Caused Damage

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Defining the Challenge Upon completion of a high-rise residential structure, cracks and delamination appeared on exterior surfaces of the tower compelling building owners to initiate a lawsuit against the general contractor. The contractor, in turn, blamed faulty materials used by subcontractors. With so many subcontractors involved in this large construction project, it seemed an almost […]

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Product Failure Analysis: Consumer Product Affected by Inappropriate Raw Material

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Soon after roofing shingles were installed, the shingle manufacturer received complaints from numerous homeowners who observed rust-colored staining discharging from the shingles. The manufacturer replaced the shingles and began an investigation into the cause of the discoloration. Their in-house testing using an industry-standard method revealed the presence of corrosion-susceptible particles that were thought to be […]

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Establishing the WTC Dust Signature: Managing Post 9/11 Environmental and Damage Assessments

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The collapse of the World Trade Center Towers following the catastrophic events of 9/11 produced a dust cloud that covered much of lower Manhattan. Thousands of private and public buildings were contaminated by the dust. Building owners in the vicinity of the collapse, worried about environmental impact to their damaged buildings, retained RJ Lee Group […]

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A Test Chamber Designed to Measure Respirable Dust for Product Stewardship

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A construction materials manufacturer needed to label its products and provide guidance for safe work practices when using its products. To do that, the manufacturer needed to know the amount of respirable dust that could be generated by workers using the products under various conditions. Workers use a variety of different tools and follow various […]

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Analyses Reveal Viaduct Concrete Failure Not Consistent

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An east coast government agency was concerned about the structural integrity of a viaduct on a main north-south highway that handled approximately 75,000 vehicles a day. The structure, which consisted of a 42-foot wide concrete deck of 40 spans and piers, was built in 1953 and was exhibiting signs of general degradation. The agency had […]

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Drywall Safety Act of 2012: Increases Regulations on U.S. Manufacturers, but May Not Improve Safety

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  • 1:50PM Feb 05, 2013
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Amidst the Post-Katrina housing boom in the mid-2000s, a domestic shortage of drywall led the United States to import Chinese-manufactured drywall to meet demand. Only months after installation, homeowners who built or remodeled using imported Chinese drywall encountered sulfur-like odors, failed air conditioning systems, and blackened metal surfaces within their homes. Many affected property owners […]

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