Based on repair material and repair construction expertise, Restruction Corporation was selected to prove methods and materials for repair of a large nuclear reactor wall cut out. The pre-placed aggregate method of placement was selected for its benefits and conformance to the following specifications:
- Low shrinkage- requirements were zero shrinkage or slightly expansive
- High early strength- 72-hour cylinder strength requirements were 5000-psi
- Thermal Coefficient- required at 0.55E-5 inches per degree Fahrenheit
- Poisson’s ratio- required value of .17 or less
- Youngs Modulus- required value of 4.0E6 pounds per square inch or greater
- Unit Weight- required 150 pounds per cubic foot or greater
Laboratory testing was completed to define the limits of cementitious components, sand additions, and additives for flow. Scaled mockups, sized at 12′ x 12′ x 3.75′ were built using plastic panels to inspect grout theology during grouting of pre-placed aggregate. Grout materials were supplied via continuous mixing and pumped with a 20g.p.m screw pump manufactured by Chemgrout. Grouting of samples took place in April 2003. Testing of cored samples was completed.