Current issues - Climate change - Greenhouse Gas reduction strategy
Factory-made composite cements incorporating intrinsically lower proportions of clinker – hence less embodied energy and with a reduced carbon footprint -are now generally available in both bulk supply and packaged in bags.
Composite cements comprise Portland cement clinker interground or blended with one or more additional inorganic constituents plus gypsum as a set regulator. Additional constituents are selected from materials such as power station fly ash, blastfurnace slag and limestone, all already familiar to UK concrete, mortar and grouting practice.
In general, the appropriate use of factory-made composite cements delivers performance equal to that of concrete containing CEM I cement. Under certain conditions, it can improve the durability performance achieved. Furthermore, in the case of use in masonry mortars within the generality of exposure conditions, factory-made composite cements can achieve the same level of performance on a one-to-one basis as a CEM I cement with the same traditional volume mix proportions.