Cotes-Palomino María Teresa, Alonso-Azcárate Jacinto, Conde-Sánchez Antonio, Dubbelman Vizcaíno Alejandro, López Ana B, Martínez-García Carmen, Martínez-Rodríguez Ana M, Revelo Rodríguez Ana Cecilia, Troyano Pérez Francisco José, Cobo-Ceacero Carlos Javier
Department of Chemical, Environmental and Materials, Higher Polytechnic School of Linares, University of Jaén, Linares, 23700, Jaén, Spain.
Department of Physical Chemistry, Faculty of Environmental Sciences and Biochemistry, University of Castilla-La Mancha, Toledo, 45071, Spain.
Environ Res. 2025 Jul 8;285(Pt 1):122321. doi: 10.1016/j.envres.2025.122321.
Lightweight aggregates (LWAs) were produced exclusively from waste-derived raw materials: aggregate washing sludge, granite cutting sludge, slate cutting sludge and cork dust. The composition and number of mixtures were designed following a protocol based on Mixture Experiments-Design of Experiments (ME-DOE). The produced materials were technologically characterized by determining the bloating index (BI), oven-dry density (ρ), water absorption (WA), strength (S), and additional parameters such as porosity and open porosity volume per specimen. Statistical models developed for BI, ρ, WA and S provided a more accurate understanding of the behavior of the mixture components and their synergistic effects, using response surface and effect plots. A cork dust content of approximately 1.5 % was established as the optimal value for maximizing BI and WA, while minimizing ρ. The resulting models are statistically significant (p-value <0.05) and showed high coefficients of determination (R: 0.80-0.94), suggesting a strong correlation with the experimental data. Moreover, predictive models were developed for the operational variables temperature (T) and optimum water content for extrusion (W) as a function of the mixture composition, supporting process manufacturing. Finally, the use of these residues in the production of LWAs has environmental benefits, with GWP reductions of between 13 and 36 % for SCS and 56-78 % for GCS compared to expanded clay lightweight aggregates, resulting in products with a lower environmental footprint.
轻质骨料（LWAs）完全由废弃物衍生的原材料制成：骨料洗涤污泥、花岗岩切割污泥、板岩切割污泥和软木粉。混合物的组成和数量是根据基于混合实验-实验设计（ME-DOE）的方案设计的。通过测定膨胀指数（BI）、烘干密度（ρ）、吸水率（WA）、强度（S）以及每个试样的孔隙率和开口孔隙体积等附加参数，对所生产的材料进行了技术表征。为BI、ρ、WA和S建立的统计模型，利用响应面和效应图，更准确地理解了混合物成分的行为及其协同效应。确定软木粉含量约为1.5%是使BI和WA最大化同时使ρ最小化的最佳值。所得模型具有统计学意义（p值<0.05），并显示出较高的决定系数（R：0.80 - 0.94），表明与实验数据有很强的相关性。此外，还针对操作变量温度（T）和挤压最佳含水量（W）作为混合物组成的函数建立了预测模型，以支持工艺制造。最后，在LWAs生产中使用这些废渣具有环境效益，与膨胀粘土轻质骨料相比，SCS的全球变暖潜能值降低了13%至36%，GCS的降低了56%至78%，从而使产品的环境足迹更小。
