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  • Sliver Spall Mitigation: Field Investigation, Laboratory Study, and Mixture Proportioning Analysis

    Abstract: A combined field and laboratory study was conducted to identify factors contributing to sliver spall of concrete pavements and recommend avenues for prevention. In this study, spall density maps of eight airfields were created, and cores were taken for petrographic analysis. A companion laboratory study evaluated nondestructive testing equipment for identifying concrete prone to sliver spalling. Concrete mix designs with good and poor performance were analyzed for trends in mixture proportioning and aggregate gradation. Spall density mapping indicated sliver spalling was more likely to occur on longitudinal joints and that the distress was not solely a material or mixture design-related issue. The laboratory study concluded that surface resistivity measurements were able to differentiate edge-finishing techniques (normal versus overworked, mortar-rich edge) after seven days of curing. An analysis of particle packing theory and mixture proportioning trends showed there was substantial overlap in the gradations for good and poor performing pavement. Thus, acceptable mixture designs can produce poor quality pavement if not constructed properly. The main contributors to early age sliver spalling of concrete airfield pavement occur during pavement construction.

  • ERDC team helps preserve history for Colorado’s Burgess-Capps Cabin

    With the help of an interdisciplinary team at the U.S. Army Engineer Research and Development Center (ERDC), the U.S. Air Force Academy Cultural Resources Management Office has plans for future rehabilitation and preservation of the historic Burgess-Capps Cabin in Colorado, keeping it standing for years to come.

  • A look back: Pinkston's 48 years of service

    After an astonishing 48 years of combined federal service, Phillip Pinkston has decided to hang his hat, celebrating both the end and beginning of two of life’s most rewarding chapters. To celebrate his well-deserved retirement, we’re taking a look back to acknowledge all he accomplished, hear from the people he positively impacted, and more.

  • Load and Resistance Factors for Earth Retaining, Reinforced Concrete Hydraulic Structures Based on a Reliability Index (β) Derived from the Probability of Unsatisfactory Performance (PUP): Phase 2 Study

    Abstract: This technical report documents the second of a two-phase research and development (R&D) study in support of the development of a combined Load and Resistance Factor Design (LRFD) methodology that accommodates geotechnical as well as structural design limit states for design of the U.S. Army Corps of Engineers (USACE) reinforced concrete, hydraulic navigation structures. To this end, this R&D effort extends reliability procedures that have been developed for other non-USACE structural systems to encompass USACE hydraulic structures. Many of these reinforced concrete, hydraulic structures are founded on and/or retain earth or are buttressed by an earthen feature. Consequently, the design of many of these hydraulic structures involves significant soil structure interaction. Development of the required reliability and corresponding LRFD procedures has been lagging in the geotechnical topic area as compared to those for structural limit state considerations and have therefore been the focus of this second-phase R&D effort. Design of an example T-Wall hydraulic structure involves consideration of five geotechnical and structural limit states. New numerical procedures have been developed for precise multiple limit state reliability calculations and for complete LRFD analysis of this example T-Wall reinforced concrete, hydraulic structure.

  • Rock Island District employee named Structural Engineer of the Year

    Eric Johnson of the U.S. Army Corps of Engineers, Rock Island District, has been named the USACE Structural Engineer of the Year. The honor, which was announced by USACE Headquarters June 30, was presented to Johnson August 5 during a virtual award ceremony conducted by Maj. Gen. Diana Holland, Mississippi Valley Division Commanding General.

  • Corps Engineers from Philadelphia District rappel, inspect Wolf Creek Dam

    JAMESTOWN, Ky. (July 25, 2013) -- The U.S. Army Corps of Engineers Special Rope Access Climb Team is one of three specialized inspection teams USACE uses for inspection purposes that travels to a variety of locations offering districts specific support tailored to the project needs. The team recently rapelled and lowered themselves 200 feet onton large spillway hydraulic radial gates at the Corps' Wolf Creek Dam, in Jamestown, Ky., July 24 to inspect 10 tainter gates for signs of corrosion or structural damage.

  • US, Indonesia exchange knowledge on structural engineering considerations to promote safety

    SENTUL, Indonesia- The sun beats down relentlessly on another habitual afternoon, as those that cannot escape the heat wipe the sweat from their brow with a heavy and tired hand. Despite the warmth, the scene is tranquil and undisturbed. However, this static calm is thrust into a dynamic upheaval of chaos from the collision of tectonic plates.