The cement industry is going through a challenging period, given the scarcity of raw materials, depletion of fossil fuel reserves, and growing environmental concerns. It is estimated that, on average, a single tonne of Portland cement releases approximately 6% of the total global man-made carbon emissions, significantly contributing to current environmental problems. The development and use of green cement can provide an excellent solution to the these pressing issues.
The concept of green cement emerged with the discovery of geopolymer cement in the 1950s. Unlike traditional Portland cement, geopolymer cement is manufactured using aluminosilicates instead of the more environmentally damaging calcium oxide. These silicates can be obtained from industrial waste materials such as fly ash, thereby making them a viable green resource.
Compared with traditional cement, green cement functions better, requires less natural materials in production, and releases less carbon dioxide. In terms of the volume of consumption, the global green cement market was valued at 138 million metric tons in 2015. According to analysts at Technavio, the market will reach 277 million metric tons by 2020, growing at a CAGR of 15%.
Top 5 Benefits of Green Cement
#1. Makes use of industrial waste
Fly ash, a by-product of coal combustion, is produced in large quantities in industrial plants. Typically, several acres of land are used to dispose of it. Green cement not only makes use of the fly ash waste, but also protects land from becoming a dumping ground and ultimately being destroyed. Apart from fly ash, green cement also uses blast furnace slag (a by-product of iron manufacturing), which can produce harmful environmental effects if it is simply discarded.
#2. Requires less energy
The materials used in the traditional cement manufacturing process require large amounts of natural gas / coal for heating purposes. Because green cement already contains industrial by-products, the energy needed in production is greatly reduced. Also, unlike Portland cement, green cement is more resistant to changes in temperature, therefore reducing the costs associated with both heating and cooling.
#3. Lowers carbon dioxide emission
Clay, sand, and pulverized limestone are some of the key ingredients used in traditional cement. These ingredients require heat, releasing approximately 5%-8% of the total global carbon dioxide. Green cement, on the other hand, does not require as much heat during its production, releasing up to 80% less carbon dioxide.
#4. Beneficial for contractors
From a commercial standpoint, green cement tends to be more beneficial for contractors than traditional cement. This is because green cement does not require extra tools or equipment and eliminates the risk of cement burns. Also, since green concrete is self-drying, a coating can be applied as early as 72-96 hours. This allows contractors to save time and prevent the loss of other projects. Further, green cement has an enhanced curing rate and stregthens very quickly, facilitating faster vertical construction, thus reducing construction time and increasing the rate of return when it comes to industrial assets.
#5. Longer lasting
Green concrete has a lower shrinkage rate and also becomes stronger far more quickly than concrete made with traditional cement. And since green concrete can withstand temperatures as high as 2400 degrees Fahrenheit, it makes buildings significantly more fire-resistant. Green concrete can also withstand acid rain, thereby reducing the risk of corrosion.
Anhui Conch Cement, CEMEX, and Italcementi are some of the leading vendors in the global green cement market.
