Belite cements, BCs, containing also minor amounts of alite, ferrite and tricalcium aluminate are widely known and occasionally used as low heat cements. Belite binders, producing high amounts of C–S–H gel, have excellent durability properties and additional advantages including: (i) lower limestone demand with lower associated CO2 emissions; (ii) lower maximum kiln operating temperature, close to 1250°C, which means lowering CO2 and NOx emissions from burning and more sustainable kiln liner maintenance; and (iii) lower temperature increase at early hydration age and chemical shrinkage which minimizes cracking.
However, the early-age strength development of standard BCs is not competitive with that of Portland cements.
Therefore, scattered research efforts are being placed on the activation of belite to improve the early-age mechanical strength developments of BCs. These new binders, which are termed active Belite cements, can be obtained by three compatible approaches at different stages of the concrete production:
(I) Chemical activation at the firing stage to stabilize more reactive (high-temperature) belite forms. For instance through sulfur-, boron- and alkaline- substitution(s) in belite.
(II) Physical activation at the cement and concrete production stages that it could include: (a) fast cooling and (b) milling at the cement production phase; and (c) relatively high temperature hydration and (d) power ultrasound at the concrete production step.
(III) Admixture activation. The use of chemical products, such as C-S-H seeds, to accelerate belite reactivity
To contribute to sustainability in the building field by producing cementitious materials with longer durability and lower embedded carbon content.
To develop, thorough a coherent collaborative effort, active belite cements with improved properties in a timely manner. The adopted approaches, to boost hydration of belite, should yield improved early-age mechanical strengths without compromising late-age mechanical strength neither durability performances.
The ways to develop the vision and mission stated above have to be worked out. The parameter space to be researched and developed is huge, so a collaborative approach would be ideal. Furthermore, if the independent investigations are carried out on a set of large-scale prepared chemically-active Belite cements, the local findings can be more easily framed within a global picture. Reporting the findings in a complete way will also help a lot.
At this stage, January-2020 to February-2021, we are just gathering expression of interest and further ideas and point of views.
If you want to express interest to know more about this initiative and to contribute from the very beginning, please send an email to, cementscience@gmail.com , with the following information:
A: Subject: Belite Research Alliance
B: Name and position. (very important: contact email address if different from the email used). Just one representative per research group
C: Institution
D1: Research group: Name of the research group
D2: Research group details (optional): One paragraph describing the ongoing and recent-past activities.
E: Any other information/idea(s) (optional):
As we are very much focused on sustainability and decreasing CO2 footprint, we intend to minimize face-to-face meetings and to use electronic means as much as possible.