Toward Infrastructure Improvement An Agenda for Research (1994) / Chapter Skim
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Science of Materials Performance and Deterioration
Science of Materials Performance and Deterioration
Pages 73-80
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From page 73... ...
A major challenge of infrastructure research is to promote a productive interaction among material scientists and practicing engineers so that fundamental advances through new material developments can be effectively integrated into practice, yielding more durable and reliable structures and system components. Research activities should enhance communication between scientists and engineers, and stimulate interaction between basic and applied research.
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From page 74... ...
Micro-cracking occurs in concrete pavements, tunnel linings, bridge structures, and pipes, while fatigue in metals and polymeric materials reduces their reliability. Sometimes this damage proceeds more rapidly than anticipated, due to unexpected usage, severe environmental conditions, or statistical extremes in material variability.
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From page 75... ...
Both PVC and HDPE membranes have been applied extensively to restrict water leakage in landfills and tunnel linings. Polyurethanes and epoxies are applied as sealants and protective coatings to a wide range of above-ground and subsurface structures.
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From page 76... ...
Coatings could signal when strain or damage to structural elements has progressed to levels warranting maintenance. CHARACTERIZATION OF DAMAGE, DETERIORATION, AND AGING Those responsible for infrastructure design and management need mathematical models and other analytical tools to select facility design characteristics, and operating and maintenance strategies to ensure cost
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From page 77... ...
Research supported by the Gas Research Institute at Cornell Universitywas undertaken to perform three-dimensional stress and deformation analyses of pipeline crossings, field test instrumented high-pressure pipelines beneath heavily loaded railway facilities, and develop standards for pipeline crossing design and installation practice. The development of new procedures and technology acceptable to many different industries required an intensely coordinated effort.
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From page 78... ...
Crack initiation and propagation in conventional materials, such as asphalt and Portland cement concrete, as well as newer plastics and composites, are difficult to observe, model, and predict. Reliable failure criteria could be developed, using stress/strain invariants, for composite materials subjected to multi-axial stress over a wide range of temperatures and loading frequencies (e.g., nuclear-waste containment facilities, fuel tanks, pipelines in environmentally sensitive sites)
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From page 79... ...
Sewage sludge and fly ash (produced by burning coal for electric-power generation) , in particular, can contain heavy metals or other constituents that may eventually leach out to contaminate water supplies or otherwise pose environmental and health hazards.
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From page 80... ...
It offers high yield strength, 12 to 16 ksi, lightweight, easy hancIling, low friction to facilitate jacking and increased hycIraulic capacity. At an 85-foot clepth, the jacking rate reached 122 feet in a 1 2-hour ship, using a mole with crunching ability to handle the glacial soil.
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