Universidade Federal de Santa Catarina (UFSC), Departamento de Engenharias da Mobilidade (EMB), Rua Dona Francisca, 8300, 89219-600 Joinville, SC, Brazil.
Université Gustave Eiffel (former IFSTTAR), Route de la Bouaye, 44340 Bouguenais, France.
An Acad Bras Cienc. 2021 Nov 22;93(suppl 4):e20201662. doi: 10.1590/0001-3765202120201662. eCollection 2021.
This manuscript evaluates the technical feasibility of reusing coal ash in the formulation design of dense asphalt mixes. Physicochemical and mineralogical properties of fly and bottom ash matrixes prepared with coal ash were analyzed by scanning electron microscopy (SEM), X-Ray diffraction (XRD), semi-quantitative spectrometry by X-Ray fluorescence (XRF) and surface characterization by Nitrogen (N2) adsorption. Filler fractions under 0.075 mm with 6.0% in weight from an entirely gneissic aggregate gradation curve taken as reference were compared to identical mixes prepared with fly and bottom ashes individually and also to a combined sample with 3.0% of each ash type. Tests on compaction ability with gyratory shear press, resistance to action of water and to rutting were carried out to compare mechanical performance. The results indicate that both gneissic and coal ash fillers do not form dipoles of effective electric attractions to bituminous matrixes, resulting in inert and hydrophilic behavior regarding to action of water, respectively. Despite surface and morphologic characteristics underlying the mechanical performance of gneissic fillers, coal ash matrixes have shown, in general, good technical feasibility to be used in asphalt mixes.
本文评估了在密级配沥青混合料的配方设计中重复利用粉煤灰的技术可行性。采用扫描电子显微镜（SEM）、X 射线衍射（XRD）、X 射线荧光（XRF）半定量光谱法和氮（N2）吸附表面特性分析，对采用粉煤灰制备的飞灰和底灰基质的物理化学和矿物特性进行了分析。以完全片麻岩级配曲线的 0.075 毫米以下重量占 6.0%的填料分数为参考，与单独采用飞灰和底灰制备的相同配合比以及采用 3.0%每种类型灰分的混合样品进行了对比。采用旋转剪切压实机进行压实能力测试、水作用和车辙阻力测试，以比较力学性能。结果表明，片麻岩和粉煤灰填料均不会对沥青基质形成有效的电吸引力偶，因此在水作用方面表现出惰性和亲水性。尽管片麻岩填料的表面和形态特征对其力学性能有一定影响，但总的来说，粉煤灰基质在沥青混合料中具有良好的技术可行性。
