Development of a Large-scale Thermogravimetry and Gas Analyzer for Determining Carbon in Concrete

Abstract

One carbon neutralization measure applied in the concrete sector is the use of artificial carbonate in concrete for immobilization. This CO₂ reduction technology corresponds to the CO₂ emitted during concrete production. When considering the marketability of these technologies, especially for newly developed products in the carbon market, it is essential to quantify the amount of CO₂ fixed as inorganic carbonate. Additionally, as a representative test specimen for concrete containing aggregate, a φ100 × 200 mm cylinder specimen is conventionally used for physical property evaluation. To evaluate the amount of CO₂ fixed in one batch of concrete, a mass far from that of the conventional chemical analysis sample may need to be analyzed. Therefore, in this study, we investigated a pulverization process for concrete analytical materials. We also propose a new analytical apparatus that can be used to measure large cylinder specimens. Experimental results showed that the newly developed analyzer, equipped with a mass balance and CO₂ and H₂O gas analyzer for large cylinders, exhibited excellent analytical variability and measurement speed performance. It was also inferred that the homogenization process is necessary to grind the entire cylindrical concrete specimen into a fine powder and homogenize it to improve the representativeness of the concrete.