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|Title:||Laboratory tests of concrete cores from the new second lock, Sault Ste. Marie, Michigan|
|Authors:||United States. Army. Corps of Engineers. Detroit District.|
Buck, Alan D.
Hallford, Charles R.
New Second Lock, Sault Ste. Marie
Sault Ste. Marie, Mich.
|Publisher:||Concrete Laboratory (U.S.)|
Engineer Research and Development Center (U.S.)
|Series/Report no.:||Miscellaneous paper (U.S. Army Engineer Waterways Experiment Station) ; C-73-8.|
Abstract: Two groups of concrete cores from the walls and floor of the New Second Lock at Sault Ste. Marie, Michigan, were tested in the laboratory with the iPtent of answering the following questions: (a) Does the concrete" show any sign of physical damage of the type that occurred in the culverts at Eisenhower Lock on the St. Lawrence Seaway? (b) Was the alr-void system of the concrete wholly or partially filled during 17 months of submergence in the lock chamber? Two groups of cores were drilled from concrete placed in the summer and fall of 1966 and the spring of 1967. The first group was drilled in 1968 and shipped dry and the second in 1969-1970 under water and shipped packed to maintain field moisture content. The outer ends of the cores from the wall and the upper ends of the cores from the floor had undergone some cycles of freezing and thawing before the concrete was submerged, The 1968 group represented the condition befor< the lock wa& filled and the 1969-1970 group the condition after 17 months of continuous submergence. Presumably, the second group was never frozen after initial submergence until selected specimens were tested in the laboratory, Every effort was made to maintain the 1969-1970'cores at field moisture content until they were tested, Selected specimens from each group were tested for air content, compressive strength, resistance to accelerated laboratory freezing and thawing, and permeability, Some petrographic observations and testing were included. Air-void spacing factors were determined for four specimens from the 1968 group. Selected specimens of nine cores of the 1969-1970 group were also tested for air content in their as-received condition by the high pressure method. It was concluded that none of the cores showed deterioration of the type found in the culverts of Eisenhower Lock; that both the air voids and additional spade were empty in the cores drilled under water and shipped and stored to retain their moisture content; that the air con tents of six of the 19 cores whose micrometric air content was determine< were too low to ensure frost protection in mature concrete but that the other 13 had adequate air in mortar. In addition, it was concluded that accelerated freezing-and-thawing tests of 6-in.-diameter cores of mass concrete do not provide results that can be readily interpreted.
|Rights:||Approved for public release; distribution is unlimited.|
|Appears in Collections:||Miscellaneous Paper|
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