* 通信作者,E-mail: wangzhengcheng194@163.com, gyc1982@aliyun.com
-
Graphical Abstract
-
Abstract
Cement production is characterized by significant carbon emissions, contributing approximately 8% of global CO2 output. At the same time, the accumulation of industrial solid waste has surpassed 60 billion tons, posing serious environmental concerns. To address these dual challenges, this study focuses on the partial or complete replacement of cement with typical alkaline industrial solid waste (AISW) for the preparation of AISW-based lightweight soil (AISW-LS). This study systematically investigates the preparation processes of AISW-LS and examines its physical and mechanical properties, durability, and microstructural characteristics. The results demonstrate that AISW can effectively replace cement, significantly reducing carbon emissions to only 35.22%-39.47% of those generated by conventional ordinary Portland cement-based lightweight soil. AISW-LS exhibits excellent flowability, with flowability ranging from 133.3 to 256.7 mm, low water absorption between 8.2% and 60.94%, low thermal conductivity in the range of 0.117 to 0.223 W/(m·K), and superior durability with coefficients ranging from 0.54 to 3.23. By adjusting the dosage of red mud, carbide slag, and soda residue or the wet density, the 28d compressive strength of AISW-LS can exceed 1.0 MPa, meeting the engineering requirements for subgrade filling. In the AISW-LS system, AISW not only serves as a structural skeleton but also accelerates the hydration of cement and activates the latent reactivity of slag. AISW-LS is environmentally friendly and economically efficient, successfully transforming environmental burdens into high-value resources. This approach provides an effective pathway for the high-value utilization of AISW and the low-carbon development of construction materials, showing great potential for widespread engineering applications.
-
-