Lessons Learned or Should Have Learned - RCC Design and Construction

ABSTRACT ONLY - Since the first application of Roller Compacted Concrete (RCC) for dam projects in 1980 (Willow Creek Dam), over 300 hydraulic structures have used RCC in the United States, with RCC volumes ranging from 1,000 to 1.3 million cubic yards. The early design pioneers learned with each successive project from mix designs, acceptable construction means and methods, lift joint treatments, monolith joints, drainage systems, and facing systems. Over 45 different design firms and 75 different contractors have completed at least one RCC project. There have also been numerous publications, specialty conferences, webinars, and other materials developed related to design requirements, design details, acceptable construction means and methods, quality control requirements, and ASTM procedures and testing protocols developed to help designers and contractors.
This paper will discuss the lessons that have been or should have been learned with regard to the application of RCC for hydraulic structures. Topics covered include the RCC mixes and applicability to different structures, facing system, lift joint preparation and treatment, technical specifications, and understanding the typical constraints of RCC construction. The use of a performance based specification over a prescribed mix and methods will be discussed. Recent specifications that do not adequately consider contractor capabilities will be discussed. Understanding limitations inherent to RCC construction should help designers develop designs that meet performance criteria while providing flexibility for contractors to construct the RCC structure.