Energetically modified cement

An EMC made from volcanic rocks (Luleå, Sweden, 2020)

Energetically modified cements (EMCs) are a class of cements made from pozzolans (e.g. fly ash, volcanic ash, pozzolana), silica sand, blast furnace slag, or Portland cement (or blends of these ingredients).[1] The term "energetically modified" arises by virtue of the mechanochemistry process applied to the raw material, more accurately classified as "high energy ball milling" (HEBM). At its simplest this means a milling method that invokes high kinetics by subjecting "powders to the repeated action of hitting balls" as compared to (say) the low kinetics of rotating ball mills.[2] This causes, amongst others, a thermodynamic transformation in the material to increase its chemical reactivity.[3] For EMCs, the HEBM process used is a unique form of specialised vibratory milling discovered in Sweden and applied only to cementitious materials, here called "EMC Activation".[4]

By improving the reactivity of pozzolans, their strength-development rate is increased. This allows for compliance with modern product-performance requirements ("technical standards") for concretes and mortars. In turn, this allows for the replacement of Portland cement in the concrete and mortar mixes. This has a number of benefits to their long-term qualities.[3]

Energetically modified cements have a wide range of uses. For example, EMCs have been used in concretes for large infrastructure projects in the United States, meeting U.S. concrete standards.[5]

  1. ^ Mark Anthony Benvenuto (24 February 2015). Industrial Chemistry: For Advanced Students. De Gruyter. pp. 134–. ISBN 978-3-11-035170-5.
  2. ^ Pentimalli, M; Bellusci, M; Padella, F (2015). Aliofkhazraei, M (ed.). "High-Energy Ball Milling as a General Tool for Nanomaterials Synthesis and Processing". Handbook of Mechanical Nanostructuring: 663–679. doi:10.1002/9783527674947.ch28. ISBN 978-3-527-33506-0.
  3. ^ a b Tole, Ilda; Habermehl-Cwirzen, Karin; Cwirzen, Andrzej (1 August 2019). "Mechanochemical activation of natural clay minerals: an alternative to produce sustainable cementitious binders – review". Mineralogy and Petrology. 113 (4). Springer: 449–462. Bibcode:2019MinPe.113..449T. doi:10.1007/s00710-019-00666-y.
  4. ^ Cite error: The named reference BournazelMalier1998 was invoked but never defined (see the help page).
  5. ^ Ronin, V (2010). An Industrially Proven Solution for Sustainable Pavements of High-Volume Pozzolan Concrete – Using Energetically Modified Cement, EMC (PDF). Washington DC, United States: Transportation Research Board of the National Academies.