LowE-CEM - Low-Energy CEMents for sustainable concrete

Concrete is the worlds most durable, reliable and economical construction material with an annual consumption in volume by society only surpassed by water. Currently, no alternatives for concrete exist which can be supplied at a sufficient scale globally. Cement is the essential “glue” in concrete with an annual world-wide production of about 3 billion tonnes and by the year 2050 experts forecast that this production will increase to above 5 billion tonnes (Figure 1). Cement is made from natural raw materials which are heated to extremely high temperatures (1450 oC) in cement kilns where they chemically transform into the so-called cement clinker. This process is highly energy demanding and in Denmark it accounts for 80–90 % of the total energy required for grey cement production which is approx. 4.4 GJ per tonne cement. This project focuses on the basic science of different chemical approaches which can lead to a significant reduction (30 – 40%) in the energy consumption associated with cement production. This goal may be achieved by four fundamental concepts: (i) reduction of the cement-kiln temperature by modification of the clinker composition, (ii) development of new supplementary cementitious materials (SCMs), (iii) partial replacement of Portland clinkers by SCMs, and (iv) development of new hydrid binders with a small fraction of Portland cement, a large fraction of an aluminosilicate-rich phase, and activated by alkaline salts. The research will be conducted in an interdisciplinary environment, utilizing state-of-the-art equipment at the academic partners for nano- and micro-scale characterization and inorganic synthesis. Moreover, macro-scale facilities for production and physical/mechanical testing available at Aalborg Portland A/S and FLSmidth A/S will be employed.