10 Jun 2020

PUBLICATION NOTICE: Investigation of Materials for Charleroi Lock and Dam Monongahela River Reconstruction Project

Abstract: The investigation described in this report was conducted for the U.S. Army Engineer District, Pittsburgh as part of a preliminary investigation of cementitious materials and concrete design pursuant to construction of Charleroi Lock and Dam Monongahela River Reconstruction Project. Local materials provided to the U.S. Army Engineer Research Development Center (ERDC) for testing included three different coarse aggregate gradations, two fine aggregate sources, a type II (MH) cement, four fly ash sources, a slag cement, a silica fume, a limestone powder, five admixtures, and two water sources. Aggregate tests consisted of sieve analysis, specific gravity, absorption, materials finer than No. 200, organic impurities, soundness, LA abrasion, clay lumps and friable particles, flat and elongated particles, lightweight particles, and petrography. All cementitious, admixtures, and water-source materials were tested for chemical and physical properties based on appropriate specifications. In addition, four mixture proportions developed by the ERDC for this project in 2005 were scaled to determine the early stiffening of mortar, freezing and thawing, and heat of hydration. This report presents the material characteristic results determined by laboratory testing in accordance with American Society for Testing and Materials procedures or regulating specification criteria.

1 Apr 2020

PUBLICATION NOTICE: Incidence of Zebra Mussel on U.S. Army Corps of Engineers Structures

Abstract: Zebra mussels (Dreissena polymorpha) are invasive/nuisance species first introduced into the Great Lakes region in the late 1980s. Since their introduction efforts have been underway to prevent and/or control their spread. Zebra mussel infestations can occur on submerged critical structure. For the U.S. Army Corps of Engineers (USACE) it is essential that hydraulic infrastructure are effectively and efficiently maintained to ensure proper water control and navigation. A study was conducted to determine the extent of the zebra mussel invasion on USACE districts and the impact zebra mussels have on USACE infrastructure. Consistent with available U.S. Geological Survey (USGS) data, it was found that zebra mussels are present within 24 of the 36 continental United States USACE district boundaries, although San Francisco and Galveston Districts have only isolated populations in non-USACE waters. Albuquerque and Omaha Districts appear to be the two districts most at risk for invasion. While infestations are common, 62% of the districts with USACE infested waters reported no or minimal impacts on the infrastructure or operation/maintenance costs. Those districts with impacts did not normally have cost figures readily available. It was also found that 12 districts have or have had zebra mussel monitoring programs in place.