Rock Breaking Using Supercritical Carbon Dioxide (SC-CO2) Technology – A Safe, Efficient, and Sustainable Approach

Rock breaking by drill and blast using chemical explosives has been a dominant method in construction. However, blasting is hazardous and risky in nature: it involves the use of Category 1 Dangerous Goods; and it induces ground vibration and risks of fly rocks and air over pressure. Mechanical rock breaking, chemical expansion agent, and hydraulic fracturing techniques, complemented with hole drilling, wedging or splitting, are sometimes used as alternatives to drill and blast for rock breaking. However, these methods are extremely slow to match with construction progress and are also costly. In particular, mechanical rock breaking brings about continuous noise, dust and nuisances to the surroundings. As more and more construction works nowadays are in congested urban region, the construction industry needs to adopt a safe, efficient, and sustainable rock breaking approach. In view of this, rock breaking using supercritical carbon dioxide (SC-CO₂) technology has been developed recently, and it has successfully been applied to numerous real projects.