Innovative Developments in Cement & Concrete Technology

The cement industry all over the world is facing a number of challenges which includes diminishing fossil fuel reserves, scarcity of raw materials, perpetually increasing demand for cements and concretes, growing environmental concerns linked to climate change and an ailing world economy. For every single tone of Ordinary Portland Cement (OPC) produced releases on an average a similar amount of CO₂ into the atmosphere, or in total roughly 6% of all man-made carbon emissions. Improved production methods and formulations that reduce or eliminate CO₂ emissions from the cement manufacturing process are thus high on the agenda. 

Approximately 3.6 billion tons of cement is produced globally every year. A conservative estimate for every 1 kg of cement produced gives a by-product of 0.9 kg of carbon dioxide this equates to 3.24 billion tonnes of CO₂ per year.

Emission reduction is also needed to counter the impacts on product cost of new regulations, green taxes and escalating fuel prices. In this regard, locally available minerals, recycled materials and (industry, agriculture and domestic) waste may be suitable for blending with OPC as substitute, or in some cases replacement, binders. Fly ash, Blast furnace slag and silica fumes are three well known examples of cement replacement materials that are in use today that, like OPC, have been documented and validated both in laboratory tests and in practice. 

The first is a by-product of coal combustion, the second of iron smelting and the third of electric arc furnace production of elemental silicon or ferro silicon alloys. Concrete is a basic building material that will continue to be in demand far into the future. A world without concrete, and its dominant precursor, Ordinary Portland Cement (OPC), is hard to imagine. Although there are different types of concrete that have been developed for use in different applications, their common virtues are familiarity, versatility, strength, durability, wide availability, fire resistance, resistance to the elements and comparatively low cost.