My primary area of research involves the durability of portland cement concrete, especially alkali-silica reaction (ASR), delayed ettringite formation (DEF), and external sulfate attack. Since my arrival at the University of Texas at Austin in 1999 as an Assistant Professor, I have served as the Principal Investigator (PI) on research projects with a total funding of over $15 million. Funding sources include the Texas Department of Transportation (TxDOT), the Federal Highway Administration (FHWA), the National Cooperative Highway Research Program (NCHRP) and various industrial sources. I have supervised over 50 graduate students since my arrival at UT, including six Ph.D. students, five of whom have entered academia as faculty members.
My main area of research emphasis is concrete durability, especially internal forms of chemical attack such as alkali-silica reaction (ASR) and delayed ettringite formation (DEF). In the area of ASR, our group has been more active than any research group in the country, with projects funded since 1999 by TxDOT, FHWA, ICAR, the National Cooperative Highway Research Program (NCHRP), and private industry. I have been taken the lead role in developing recommended practices for preventing ASR in new concrete construction, and our recently published FHWA report is now being considered for adoption by both the American Association of State Highway Officials (AASHTO) and the American Society for Standards and Testing (ASTM). The basis for these recently developed guidelines is research performed at UT over the past 10 years, including the results of accelerated laboratory tests and long-term outdoor exposure site testing. Our outdoor exposure site at the J.J. Pickle Research Campus is the most extensive of any in North America, with over 400 outdoor specimens comprising a range of reactive aggregates, cements, supplementary cementing materials, and chemical admixtures. I have been a PI on several durability-related projects funded by TxDOT and have taken the lead in developing test methods, specifications, and guidelines for preventing deterioration caused by ASR, DEF, freezing and thawing, and external sulfate attack.
In 2006, I was the PI for a research team recognized for the development of ConcreteWorks, a software package for optimizing concrete mixtures. Our team received an award for Top Research Innovations and Findings for 2005, awarded by the Texas Department of Transportation (TxDOT) for research conducted under TxDOT Project 4563, “Prediction Model for Concrete Behavior,” including the development of ConcreteWorks. This software program has been used throughout the United States for a variety of construction projects, including Dallas Area Rapid Transit (DART) projects and the Hoover Dam Bypass. ConcreteWorks includes modules for predicting heat generation in various concrete elements, the cracking potential of mass concrete and bridge decks, and the service life of reinforced concrete structures exposed to external chlorides.
In 2008, I was named Chair of the International Alkali-Aggregate Committee and I was the United States representative on the RILEM TC 191-ARP (Alkali-Aggregate Reactivity) Committee. I served as the Chair of the 14th International Conference on Alkali-Aggregate Reaction in Austin, TX in 2012.
From 2008 to 2012, I served as Chair of the American Concrete Institute (ACI) Committee 201 - Durability which is the primary ACI committee tasked with developing durability guidelines for key ACI products, such as building codes and specifications. From 2008 to 2010, I also served as a voting member of ACI 318-A (General, Concrete, and Construction), which is the subcommittee within ACI 318 that is charged with integrating durability requirements into the Building Code.
My main area of research emphasis is concrete durability, especially internal forms of chemical attack such as alkali-silica reaction (ASR) and delayed ettringite formation (DEF). In the area of ASR, our group has been more active than any research group in the country, with projects funded since 1999 by TxDOT, FHWA, ICAR, the National Cooperative Highway Research Program (NCHRP), and private industry. I have been taken the lead role in developing recommended practices for preventing ASR in new concrete construction, and our recently published FHWA report is now being considered for adoption by both the American Association of State Highway Officials (AASHTO) and the American Society for Standards and Testing (ASTM). The basis for these recently developed guidelines is research performed at UT over the past 10 years, including the results of accelerated laboratory tests and long-term outdoor exposure site testing. Our outdoor exposure site at the J.J. Pickle Research Campus is the most extensive of any in North America, with over 400 outdoor specimens comprising a range of reactive aggregates, cements, supplementary cementing materials, and chemical admixtures. I have been a PI on several durability-related projects funded by TxDOT and have taken the lead in developing test methods, specifications, and guidelines for preventing deterioration caused by ASR, DEF, freezing and thawing, and external sulfate attack.
In 2006, I was the PI for a research team recognized for the development of ConcreteWorks, a software package for optimizing concrete mixtures. Our team received an award for Top Research Innovations and Findings for 2005, awarded by the Texas Department of Transportation (TxDOT) for research conducted under TxDOT Project 4563, “Prediction Model for Concrete Behavior,” including the development of ConcreteWorks. This software program has been used throughout the United States for a variety of construction projects, including Dallas Area Rapid Transit (DART) projects and the Hoover Dam Bypass. ConcreteWorks includes modules for predicting heat generation in various concrete elements, the cracking potential of mass concrete and bridge decks, and the service life of reinforced concrete structures exposed to external chlorides.
In 2008, I was named Chair of the International Alkali-Aggregate Committee and I was the United States representative on the RILEM TC 191-ARP (Alkali-Aggregate Reactivity) Committee. I served as the Chair of the 14th International Conference on Alkali-Aggregate Reaction in Austin, TX in 2012.
From 2008 to 2012, I served as Chair of the American Concrete Institute (ACI) Committee 201 - Durability which is the primary ACI committee tasked with developing durability guidelines for key ACI products, such as building codes and specifications. From 2008 to 2010, I also served as a voting member of ACI 318-A (General, Concrete, and Construction), which is the subcommittee within ACI 318 that is charged with integrating durability requirements into the Building Code.