Carbon Capture Through Construction and Demolition Waste

To reduce the carbon footprint of cementitious materials, the capacity of CO2 sequestration by recycled concrete aggregate (RCA) through accelerated carbonation is widely investigated. Studies showed that the carbonation process will not only promote a reduction in carbon footprint but can also increase recycled aggregate performance by enhancing their properties and promoting their usage in the construction industry. At first, recycled concrete aggregates of both fine and coarse granulometry were produced by crushing S-type pavers and were characterized. The adhered mortar attached to the aggregate surface was determined by a 10% HCl hydrochloric solution, which revealed 28% cement paste and 31% mortar attached in fine and coarse RCA fractions, respectively. The accelerated carbonation was promoted using a climatic chamber in two conditions, 0,04% and 5% CO2 inside the chamber. The CO2 captured potential was determined by the mass gain method and differential thermogravimetric analysis (DTA/DTG), which revealed a potential from 1.66 to 25.30% of CO2 uptake. The effect of the carbonation process on RCA was evaluated through density and water absorption, which revealed an increase in recycled aggregate properties after the carbonation process.