CO₂ source is one of the limiting factors for popularizing the accelerated carbonation technology in recycled concrete aggregates (RCAs) improvement. In this paper, the feasibility of using flue gas (CO₂ content of 20 %) from cement plant as alternative CO₂ source to improve RCAs was systematically studied and evaluated. Results showed that the carbonation extent and physical properties of the RCAs treated by flue gas were obviously improved and were comparable to those treated by commercial mixed gas with CO₂ content between 20 % and 100 %. Based on the results of thermal gravimetric (TG), fourier transform infrared (FTIR) and X-ray diffraction (XRD) analysis, calcium hydroxide and calcium silicate hydrates in RCAs were significantly transformed into calcium carbonate at the optimal gas flow rate (5 L/min) after 168 h of treatment. The workability, compressive strength and flexural strength of concrete incorporating carbonated RCAs treated by flue gas were comparable with those treated by mixed CO₂ gas, but were much better than those of concrete containing non-carbonated RCAs at all the replacement rate. Finally, the environmental impact and economic feasibility using flue gas to improve RCAs were evaluated based on a combined waste recycling system. All indicated that flue gas could be effectively utilized as CO₂ source to improve RCAs.

CO ₂源是在再生混凝土集料（RCA）改进中推广加速碳化技术的限制因素之一。本文系统地研究和评估了使用水泥厂烟气（CO ₂含量为20％）作为替代CO ₂来源来改善RCA的可行性。结果表明，烟道气处理后的RCA的碳化程度和物理性能均得到明显改善，可与商业混合气中CO ₂处理的RCA相比。含量在20％至100％之间。根据热重（TG），傅立叶变换红外（FTIR）和X射线衍射（XRD）分析的结果，RCA中的氢氧化钙和硅酸钙水合物在最佳气体流速（5 L / min），治疗168小时后。烟道气处理的掺入碳酸RCA的混凝土的可加工性，抗压强度和弯曲强度与CO ₂混合气处理的混凝土相当，但在所有替代率下，其性能均好于非碳酸RCA的混凝土。最后，基于联合废物回收系统，评估了使用烟气改善RCA的环境影响和经济可行性。都表明烟道气可以有效地用作一氧化碳改善RCA的_2个来源。