Thousands of bridges across the country need repair and modernization, with the impact on the economy going way beyond the cost of reconstruction, particularly for the supply chain. These blockages have cost hundreds of millions of hours of productivity from trucks idling in traffic when bridges fail or while road crews are working on them. Aging bridges are part of…
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Concrete has been used as a strong, durable building material for thousands of years, dating back to ancient structures that are still standing to this day. Yet, it has one fundamental enemy it can’t escape—water. As an uptick in humidity and rainstorms wash across many regions throughout much of the calendar, water infiltration can lead to issues such as below-grade…
Read MoreAccording to the Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy, homes and commercial buildings consume 40 percent of the energy used in the United States. The average American spends at least $2,000 annually paying for energy, with about $200 to $400 of that bill going towards regulating temperatures caused by drafts, air leaks around openings and…
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As architects design new high-rise buildings taller and with more complexity, producers are challenged to deliver ready-mix concrete that can be pumped, placed, and finished effectively for these structures. High-rise buildings (defined as those that are 75 feet or higher from the lowest level of fire department vehicle access to the floor of highest occupiable space) typically require higher strength…
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By Lou Colarusso and Samuel Barker Throughout the past decade, committee members and key industry players attending meetings held by leading organizations [Concrete Reinforcing Steel Institute (CRSI), American Concrete Institute (ACI) and others] frequently engaged in unofficial discussions centered around what changes needed to be made to advance the reinforced concrete construction industry and to improve constructability and job site…
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When placing in cold weather, extra precautions must be taken to ensure concrete sets properly and gains adequate strength. The Transtec Group, Texas-based concrete pavement practitioner, notes how the first few days after placement are the most important because that is when cement hydration reaction proceeds the fastest and concrete gains most of its compressive strength. However, cold conditions slow the hydration process, meaning that concrete placed in low temperatures gains less strength than the same mix in warmer temperatures during the same length of time. If the water in the concrete mix freezes, the hydration process stops completely. Even if it thaws, strength gain may not recover.
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An 850-ft. mixed-use tower has rapidly climbed into the Seattle skyline on the strength of a unique core wall system with requisite volumes of high performance concrete but no conventional rebar. Topped out in early August, Rainier Square Tower marks the debut of what Seattle engineer Magnusson Klemencic Associates (MKA) dubs the Concrete-Filled Composite Plate Shear Wall (CPSW) system.
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Material science behind lightweight concrete and self-consolidating mixtures yields a principal element of the Monarch Sanctuary, a 15-ft. “vertical butterfly meadow” prototype on display at the Cooper Hewitt Smithsonian Design Museum, New York City.
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Concrete paving is pretty complex and achieving quality, long-lasting results requires skill, the right equipment, and advanced technology. At its root, pavement is an outdoor floor … a hardscape surface covering that is driven or walked on. One of the major advantages of concrete pavements is they are typically stronger and more durable than other types of surfaces. They also can be grooved to provide a tough, skid-resistant surface. A notable disadvantage is that they typically can be more time-consuming to construct. Thus, concrete contractors have turned to technology for production-enhancing efficiencies and improved results.
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Materials are the critical component of durable transportation infrastructure, and as such got strong coverage at the 99th annual Transportation Research Board meeting earlier this year in Washington, D.C. There, some 12,000 delegates audited presentations in over 800 sessions, which addressed many aspects of transportation design, construction and policy, and encompassed infrastructure built with cast-in-place concrete.
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