New Publication By RJLG’s Concrete Expert Dr. Eric Giannini


Dr. Eric R. Giannini, RJ Lee Group’s expert in concrete durability, test method development, and nondestructive testing, has co-authored a new publication in Journal of Advanced Concrete Technology. The article is titled “Monitoring Alkali-Silica Reaction Significance in Nuclear Concrete Structural Members.”

This paper provides an overview of ongoing research sponsored by the US Department of Energy’s Light Water Reactor Sustainability Program. The issue of alkali-silica reaction (ASR) in concrete nuclear power plant structures has been of considerable interest in recent years, following its detection in plant structures in the United States, Canada, and Japan. Although only two plants are currently under construction in the United States today, the vast majority of plants are over 30 years old, and either have renewed or will seek renewal of their initial 40-year operating licenses, permitting them to operate to an age of 60, or even 80 years 1 (Kurtis et al. 2017). This extended service life comes with increased potential for a variety of concrete distresses, including ASR.

The effects of ASR on concrete structures in general have been extensively studied, and this project seeks to address critical knowledge gaps related to certain nuclear power plant structures. Many of these structures are very thick and lack through-thickness shear reinforcement (though they are generally well-reinforced and confined in the in-plane direction. This has the effect of focusing the expansion caused by ASR in the out-of-plane (thickness) direction, while substantially limiting any expansion in the in-plane directions that would be visible for inspection. As a result, there are questions regarding both the residual shear capacity, given that the unreinforced direction sustains the greatest expansion and damage from ASR, and the ability of power plant owners to detect the presence of ASR, given that indications of distress on the visible surface may considerably lag the development of distress in the interior of the concrete.

The research discussed in this paper takes place at the University of Tennessee Knoxville and will seek to address these questions two phases of experiments on three large-scale specimens. I was engaged to provide support with specimen design and fabrication, mostly with regards to designing reactive and non-reactive concrete mixtures, and the practicalities of avoiding thermal issues with casting such massive concrete elements in the summer. The latter required nearly 10,000 pounds of ice to keep the fresh concrete temperatures below 70°F. Following successful fabrication, the specimens are being conditioned in an environmental chamber to accelerate the development of ASR, and extensively monitored using multiple techniques to advance our understanding of how to detect ASR in similar structures. After approximately two years of conditioning and monitoring, the specimens will be destructively tested to evaluate the impact of ASR on their residual shear capacity.

A video produced by the University of Tennessee-Knoxville with further information on the project can be found here: https://youtu.be/hwynrQY42Xs

To read the paper in its entirety, please click here.

 

1.) Kurtis, Kimberly E., Yunping Xi, Michał A. Glinicki, John L. Provis, Eric R. Giannini, and Tengfei Fu. “Can we design concrete to survive nuclear environments?” Concrete International 39(11) (2017): 29-35.

 

 


Eric R. Giannini, Ph.D., P.E.

About Eric R. Giannini, Ph.D., P.E.

Dr. Eric R. Giannini joined RJ Lee Group’s expert team in 2017 and brings his expertise in concrete durability, test method development, and nondestructive testing. Prior to joining RJ Lee Group, Dr. Giannini was an assistant professor in the Department of Civil, Construction, and Environmental Engineering at The University of Alabama from 2012 to 2017. At Alabama, he was awarded over $1.8M in external funding as PI or co-PI from a broad portfolio of federal, state, and industry sponsors including the National Science Foundation, Department of Energy, Federal Highway Administration, Alabama Department of Transportation, and Portland Cement Association (Southeast Region). Over the past 10 years, he has contributed to or led numerous research projects related to alkali-silica reaction (ASR) in concrete, addressing aggregate test methods, assessment and monitoring of field structures, and the development of laboratory mockups to simulate the development of ASR at multiple length and time scales. Dr. Giannini has partnered with experts in NDE and structural health monitoring (SHM) to investigate and validate the potential of new technologies to monitor the progress of ASR in concrete nuclear structures. As a PCA Educational Foundation Graduate Research Fellow, he developed an innovative ultra-rapid autoclave test method to assess the ASR potential of aggregates; this work was continued by a doctoral student under his supervision at The University of Alabama as her dissertation topic, and provided considerable insight into the mechanisms of ASR at very high temperatures and alkali loadings.

Dr. Giannini also has an interest in the potential of bamboo as a construction material; he has directed research on the mechanical properties of bamboo grown and harvested in the U.S. and coordinated an NSF-funded summer research program for undergraduate students focused on the engineering properties and behavior of bamboo.

Dr. Giannini has a Ph.D. in Civil Engineering from The University of Texas at Austin and is a licensed Professional Engineer in the Commonwealth of Virginia. He also worked on submarine overhaul and repair projects as a Naval Architect for five years at Norfolk Naval Shipyard, focusing on ship stability (weight and moment control) and dry docking operations. He was a key contributor to the success of emergent repair projects following two grounding incidents. He was named an ASCE ExCEEd Teaching Fellow in 2013 (one of 24 early-career faculty in the US that year) and a PCA Educational Foundation Research Fellow in 2010. Dr. Giannini is active in several technical and professional organizations, including the American Concrete Institute (ACI), ASTM International, RILEM, and American Society of Civil Engineers (ASCE). He served as the inaugural chair of the ACI 228-B subcommittee on Visual Inspection from 2012 to 2015.

Contact Eric Giannini