New formulations enable contractor to fill the annulus between 30-inch casing and internal conduits feeding downtown Austin. MOST UTILITIES USE HORIZONTAL BORING OR PIPE JACKING TO PLACE LARGE-DIAMETER STEEL OR POLYETHYLENE CASINGS UNDER ROADWAYS. Utility services can then be run through the various sizes of conduits placed within the casings. But when electrical cables are placed within these conduits, challenges can escalate. Because heat is generated within underground cables, the annulus between the casing and the internal ducts must be filled with a thermally conducting grout to help dissipate the heat. And these grouts must not only have superior thermal properties, but they also must have proper flow characteristics and heat of hydration characteristics. The challenges are compounded as pumping lengths are increased.
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