Marc Zacharias, Calmetrix
Operational Considerations for an Isothermal Calorimeter and Calibration
This talk will discuss fundamental aspects of calorimetry including sample preparation and the importance
and methods for calibration, regardless of instrument brand.
Dr. Kevin Folliard, University of Texas Austin
University of Texas Laboratory Tour
Dr. Kevin Folliard, host of the conference, will provide a short tour of the facilities at the University of Texas Austin Austin.
Rusty Winters, Capitol Aggregates and Cement
Using Calorimetry in Concrete Technology
Rusty is a concrete industry veteran with over 35 years’ experience in concrete technology and marketing. Currently based in San Antonio, TX as the Director of Technical Service and Marketing for Capitol Aggregates and Cement. Experienced in mix design and all QC functions as well as troubleshooting concrete problems, he has worked on many product development projects in the industry. Committee member of ACI, ASTM, SDI, and a board member of the NRMCA. Rusty has presented various topics to all of the CIM programs and a numerous industry events over the years.
Nick Popoff, Votorantim
A Manufacturer's Approach to Optimizing Gypsum in Cement
Gita Charmchi, Votorantim
Sulfate Optimization of Cement Using Isothermal Calorimetry
Paul Sandberg, Calmetrix
Update on ASTM Standards Activity
This talk will discuss on the activities of ASTM as it relates to the cement and concrete industry, including
a new standard for sulfate optimization.
Jeremy Wheeless, University of Texas Austin
Using Calorimetry as an Index for Predicting Sulfate Resistance of Class C Fly Ash
Decades of research have shown that high calcium fly ash, when used as a partial replacement of portland
cement, produces a binder that is susceptible to external sulfate attack. Previous research studies have shown
that the external sulfate attack mechanism that propagates from these blends can be suppressed by using gypsum as an admixture. In this research study calorimetry and x-ray diffraction investigative techniques were used to show how gypsum affects the hydration kinetics and early age hydration products that form in these types of binders. Quantifying the hydration products that contribute to the external sulfate attack mechanism and correlating them to the amount of heat produced by the binder is key to determining the gypsum dosage required to mitigate the deleterious effects of external sulfate attack in these blends. The use of these investigative techniques may allow for the more widespread use of high calcium fly ashes in portland cements.
Jeremy Wheeless is a graduate research assistant at The University of Texas at Austin at the Laboratory for Infrastructure Materials Engineering. Jeremy has practical experience as a construction worker, having worked as a journeyman ironworker for the local ironworker’s union in central Texas for 7 years. He is passionate about the building industry, and civil infrastructure. He is a registered Engineer in Training in the state of Texas and is soon to be employed by Wiss, Janney, Elstner and Associates.
Dr. Fred Aguayo, Texas State University
Using Isothermal Calorimetry to Evaluate Early-age Reactivity of Calcium Aluminate Cements (CACs)
Note that Dr. Aguayo has also arranged a tour of the Texas State facilities starting at 2 p.m. on Thursday May 17. Contact Fred for more information, and refer to the schedule.
Dr. Peter Stynoski, US Army Construction Engineering Research Laboratory
Juxtaposing Joules: The Advantages and Pitfalls of In-situ Mixing
Isothermal calorimeters offer uniquely precise quantification of exo- and endothermic reaction progress. Recent software enhancements have improved calorimeter accuracy and facilitated data interpretation. However, when measuring cement hydration in a calorimeter, conventional mixing procedures require disposal of the first hour of data and may introduce shear history variation across specimens. These issues compound for alternative binders, such as slag and fly ash blends activated by alkali-silicate solutions, because the shearing action of mixing and the timing of mixture component addition play significant roles in early reaction mechanisms. Such challenges may extend to the latest Portland cement concrete admixtures. This presentation discusses the use of an in-situ mixer accessory in an isothermal calorimeter optimized for sample volumes of between 20 mL to 40 mL to fully elucidate the impacts of mixing time, reaction temperature, and mixture component ratios. Results clearly show the contribution of the mixer itself to the power curve. As expected, higher viscosity samples show higher baseline power input by a mixer set at a constant rotation rate, though variations of several milliwatts can occur across different trials of the same type of mixture. For the binder tested here, extending the mixing time affected the total heat by far more than the baseline heat contributed by mixing alone. After identifying these nuances of in-situ mixing, controlled tests isolated the effects of reaction temperature and component ratios without discarding critical data gathered within the first few hours after mixing.
Dr. Stynoski is a recent graduate of the Construction Materials program at the Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign. At CERL, he pursues pioneering infrastructure materials technology and identifies pathways to transfer new knowledge into military and civilian applications. He has contributed to CERL projects investigating large-scale additive manufacturing of concrete, geopolymer mixture design and methods of construction for large-scale infrastructure, adhesion of geopolymers to metals, and reinforcement of high-temperature ceramics. As an active member of the American Concrete Institute, Dr. Stynoski has maintained voting and associate membership on several ACI technical committees and sub-committees, including 236 Material Science and 241 Nanotechnology. His diverse publication list encompasses high-impact journals and high-profile conferences covering material science, mechanical engineering, and biological fields of study.