Bio-based lightweight aggregates are a novel type of lightweight aggregates. The use of plant-based aggregates in concrete effectively decreases its bulk density, the environmental impact and improve the thermal insulation property. However, the application of plant-based aggregate in ordinary cement-based concrete still faces critical problems, for instance, the polysaccharide leached from the plant retards the hydration of clinker and lead to degradation of concrete strength. In this study, a novel bio-based cold-bonded lightweight aggregates (BCBLWAs) was developed with the use of converter steel slag and miscanthus powder via CO₂ curing. The aggregates using steel slag as a binder show relatively high strength and low density with the use of miscanthus. The polysaccharide leached from miscanthus powder, which negatively influences the cement-based aggregates, has no influence on the artificial carbonated steel slag aggregate. The developed BCBLWAs obtained compressive strengths from 0.58 MPa to 5.3 MPa and loose bulk densities from 550 kg/m³ to 1300 kg/m³. The reaction products and microstructure of BCBLWAs after carbonation curing were characterized by TGA, XRD, SEM and nitrogen physisorption. The CO₂ uptake capacity of BCBLWAs was also evaluated. Furthermore, the prepared BCBLWAs were utilized to prepare a lightweight concrete, which obtained optimal compressive strength (28.5 MPa), dry bulk density (1630 kg/m³) and thermal insulation (0.439 W/(m⋅K)). The effect of BCBLWAs on the hydration of cement was also evaluated to be minor and only showed a slight retardation effect. The lowest thermal insulation of BCBLWAs incorporated lightweight concrete reached 0.255 W/(m⋅K).

生物基轻骨料是一种新型的轻骨料。在混凝土中使用植物性骨料可有效降低其容重、环境影响和提高保温性能。然而，植物基骨料在普通水泥基混凝土中的应用仍面临着严重的问题，例如植物浸出的多糖会阻碍熟料的水化，导致混凝土强度下降。在这项研究中，使用转炉钢渣和芒草粉通过 CO ₂开发了一种新型生物基冷粘结轻骨料 (BCBLWAs)。养护。使用钢渣作为粘合剂的骨料在使用芒草时表现出较高的强度和较低的密度。芒草粉浸出的多糖对水泥基骨料产生负面影响，对人工碳化钢渣骨料无影响。开发的 BCBLWA 获得了 0.58 MPa 至 5.3 MPa 的抗压强度和 550 kg/m ³至 1300 kg/m ^{3 的}松散体积密度。通过TGA、XRD、SEM和氮物理吸附对碳化固化后BCBLWAs的反应产物和微观结构进行了表征。二氧化碳₂还评估了 BCBLWA 的吸收能力。此外，制备的 BCBLWA 用于制备轻质混凝土，获得最佳抗压强度 (28.5 MPa)、干容重 (1630 kg/m ³ ) 和绝热性 (0.439 W/(m·K))。BCBLWAs 对水泥水化的影响也被评估为很小，仅显示出轻微的缓凝效果。包含轻质混凝土的 BCBLWA 的最低隔热性能达到 0.255 W/(m·K)。