@article{b1215df50ff7402ab94172dc562cbe21,
title = "A new hypothesis for air loss in cement systems containing fly ash",
abstract = "Although there are many benefits gained from incorporating fly ash into concrete, carbon contamination in the fly ash has been shown to interfere with the efficacy of organic additives in an unpredictable manner. This work uses surface tension measurements to quantify the adsorption of air-entraining agents (AEA) onto cement and fly ash. Both the adsorption capacity of the adsorbents and the adsorption isotherms indicate that the fly ash particles, rather than the carbon itself, dominate adsorption in a carbon-contaminated ash in cement pore solution. We propose that adsorption onto fly ash particles and cement actually improve air entrainment via Pickering stabilization. While the carbon is still expected to contribute to air loss via hydrophobic adsorption of the surfactants, we suggest that the primary way in which the carbon interferes is by shielding surfactant-coated fly ash particles from participating in air development and Pickering stabilization during mixing.",
keywords = "Adsorption isotherm, Cement, Fly ash, Particle or Pickering stabilization, Surface tension",
author = "Tunstall, {Lori E.} and George Scherer and Prud'homme, {Robert K.}",
note = "Funding Information: This work was funded by NSF grant CMMI-1335320 . The information presented in this paper does not necessarily reflect the opinion or policy of the federal government and no official endorsement should be inferred. We thank Fabien Georget for prediction of the speciation in solution, Peng Zhao for conducting XPS analysis, and Silvio Dantas for performing BET analysis on the HCCF and LCCF. We also thank Sika Corporation, Buzzi Unicem USA, and Headwaters Resources for their cooperation and provision of materials. Funding Information: This work was funded by NSF grant CMMI-1335320. The information presented in this paper does not necessarily reflect the opinion or policy of the federal government and no official endorsement should be inferred. We thank Fabien Georget for prediction of the speciation in solution, Peng Zhao for conducting XPS analysis, and Silvio Dantas for performing BET analysis on the HCCF and LCCF. We also thank Sika Corporation, Buzzi Unicem USA, and Headwaters Resources for their cooperation and provision of materials. Publisher Copyright: {\textcopyright} 2021 Elsevier Ltd",
year = "2021",
month = apr,
doi = "10.1016/j.cemconres.2021.106352",
language = "English (US)",
volume = "142",
journal = "Cement and Concrete Research",
issn = "0008-8846",
publisher = "Elsevier Limited",
}