Introducing the Extraordinary Leuven Cement: Raw Materials, Process, Performance, and First Real-Life Applications
The development of alternative cementitious binders has been primarily fueled by the need to reduce the environmental footprint of Ordinary Portland Cement (OPC). It would be reasonable to expect though that these new binders to come should be on one hand better in terms of environmental footprint, and on the other hand, at least comparable in terms of performance and availability to society. The latter, in engineering terms, translates into a production process that is relatively easy to erect, technically and financially, and robust during operation. Moreover, the binder itself should be composed of abundant elements so as to empower construction and growth for all. The most abundant elements in earth’s crust are oxygen, silicon, aluminum, iron, calcium, and sodium. Assuming a high-temperature process is employed, then the parent minerals where these elements are present are of little interest: they will all melt, and by adjusting the chemistry and the cooling conditions, the solidified product will be the glass precursor to be used as the main component in the cementitious binder thereafter.
In the work herein, we present our approach to meet all the above. We try to translate intentions (i.e., develop a binder of low environmental footprint and abundant to all) into actions (i.e., develop and test the process and the materials), respecting the obvious boundaries of the system (i.e., thermodynamics).
The work is structured around the production process of this new binder. It starts with an overview of the different steps (i.e., unit operations) and continues with in-depth presentation of raw materials, firing conditions, milling, additives, (…), concluding to the two lines of binders that have been developed over the past years, one with OPC (blended) and the other one without. In addition to OPC, these formulations can also integrate other materials, namely, ground granulated blast furnace slag, fly ash, calcined clays, and more, thus, resemble to a great extent the family of blended cements in the market today. The data communicated refer to work conducted at both laboratory and pilot-plant scale, and extend from the atomic structure of these new binders to mortar formulations and ultrahigh strength concrete.
The name of this new binder is Extraordinary Leuven Cement. It is abbreviated as ELCE, suggesting that “elce”, an obsolete form of “else”, i.e., something different is a possibility even for one of the most massively used materials today.