Beneficiated Fly Ash Research Project:
Because a reliable, consistent source of fly ash is so critical to the concrete’s industry ability to produce durable, high performance concrete TCA has been active in lobbying the Tennessee Valley Authority to switch from landfilling fly ash at several coal-fired power plants in Tennessee to investing in one of several beneficiation processes that could turn TVA’s disposal problem into a profit opportunity while preserving and extending a vital resource for the concrete industry in Tennessee and surrounding states. (See more information on this effort in our Public Policy section)
To support our work to bring more beneficiated fly ash to the market in Tennessee, TCA worked with long-time research partner Dr. L.K. Crouch at Tennessee Technological University to do a study on the impact of using beneficiated fly ash in concrete mixtures utilizing common Tennessee materials. The research was performed by students at TTU in the summer of 2018. An abstract of the research project can be seen HERE. This research will be presented by TTU at the 2019 World of Coal Ash.
ACI 332 Mix Design Research:
The TCA Technical Committee came together to test both the fresh and hardened properties of mixes typically supplied for residential concrete driveways. Different mixes were run in the lab to simulate what happens to concrete when a producer’s mixes are subject to the addition of water (often significant amounts of water) at the jobsite. Tests were run to determine properties both before and after the addition of water, including the collection of calometric data above to show the impact of water addition on set times. While there were no surprises in the data, it was very useful to show not only the reduction in the strength that comes from water addition, but also the increase in set time. Data can be found HERE and the "one-pager" summarizing ACI 332 requirements can be found HERE.
Portland Limestone Cement (PLC) Research:
PLC is not widely used in Tennessee as of 2018, with only one cement supplier marketing PLC in Tennessee (at only one terminal in Memphis, TN). However, it appears that PLC may increase in both availability and use going forward so TCA responded to a research request from students at TTU interested in comparing concrete mixtures utilizing PLC to those using conventional Type 1 cement. TCA helped in getting a sample of PLC to the TTU campus and students were able to begin their research. A plan of the research can be seen HERE.
Commercial & Residential Enhanced Durability (CRED) Research:
This study was undertaken to support the work of the TCA Technical Committee with regard to ACI 332 and exterior concrete durability. Because of the increasing prevalence of magnesium chloride in commercially available de-icing products, this research was designed to focus on potential impacts from the use of these products on common concrete mixtures being used in Tennessee. Phase One of the study was completed in 2018 and results can be seen HERE. As expected, impacts of the use of de-icers can be measured and the research demonstrated these impacts.