Bio cement – An efficient alternative to Synthetic cement
Bio cement is a cementing material as strong as the synthetic cement that is made by various processes in industry. Production of synthetic cement yields out annually 5% of anthropogenic CO2 that contribute to air pollution and greenhouse effect. As described in Britannica Encyclopedia, the extreme heating of the cementing material such as clay and sand at more than 1000℃ lead to the release of CO2 in to the atmosphere.
A novel method is under investigational research to escape from this process and replace synthetic cement with sustainable and eco-friendly cement.
Bio cement and its types:
Basically, cementing material can be prepared from microorganisms by precipitation which is also called Biomineralization. There are 2 types of Bio cement – Calcium carbonate that is used for construction and Calcium phosphate which is used for bone regeneration.
Organisms that have ability to produce urease enzyme can metabolize nutrients and trap carbon in the form of carbonate combined with calcium to produce calcium carbonate; and phosphorous to produce calcium phosphate. Any natural source of essential nutrients that include urea and calcium can be given for such organisms. Metabolic cycles of each organism are studied for the same.
Calcium carbonate:
Calcium carbonate is bio cement that is used for construction of buildings and infrastructure, these are obtained from precipitation of carbonates along with calcium by organisms which can metabolically so. Bio cement crystals produced in such way are much bigger than the synthetic ones and can be used efficiently as to cover the pores, cracks and holes of deteriorating structure, so that it can self heal. The durability is longer than synthetic ones which is an advantage.
The bricks thus made can also be termed as bio bricks. Many researches are ongoing about the other methods to increase the productivity of such cement so that it can reach the demand globally as construction industry is a fast-growing economy. Success of such research can lead to pollution free production of construction cement.
Calcium phosphate:
Calcium phosphate is a cementing material used in medical application for bone regeneration. In order to heal the cracked or broken bones, it is necessary to surround it with a strong agent so that the broken bones do not move and can heal itself. So far, calcium phosphate is used for cranial bone, knee joint replacement etc.
Use of calcium phosphate has paved way for a better treatment as these are safe & efficient.
The main advantage of such bio cement is its versatile nature, that it can be used in solid (powdered) and also in semisolid (paste) form. Other sources of bio cement are cockle shells, microalgae, metabolic enzymes isolated from organisms.
Author : Janet Simon
