The transition towards a Circular Economy necessitates the development of methodologies for optimal utilization of secondary resources. One such resource is sewage sludge ash (SSA). SSA can be utilized in construction materials, but as it contains a high concentration of the critical raw material phosphorous (P), extraction of P before the use in construction materials must be considered. EasyMining in Sweden has developed a method for acid extraction of P (Ash2Phos). This work investigates the use of the acid-washed SSA from this process (AW-SSA) in concrete; as partly sand or cement replacement. Castings of mortar prisms showed that a 10% direct replacement of the sand fraction was not possible, as the AW-SSA had a high water demand. Subsequently, the workability was too low for casting. Grinding the AW-SSA before use as cement replacement, on the other hand, gave encouraging results. At 10% replacement, the mortar had a similar 28-day compressive strength as the reference. The Strength Activity Index and Frattini Test did not show conclusive results; however, the AW-SSA is probably not pozzolanic. However, the ground AW-SSA likely has a (latent) hydraulic nature, positively influencing late strength development. The 42-day compressive strength of mortar with 10% replacement exceeded that of the reference with about 5 MPa. This latent hydraulic nature underlines an interesting potential for transforming SSA into two products; phosphorous and material for partly cement replacement in concrete.

向循环经济过渡需要开发优化利用二次资源的方法。其中一种资源是污水污泥灰分 (SSA)。SSA 可用于建筑材料，但由于它含有高浓度的关键原材料磷 (P)，因此必须考虑在用于建筑材料之前提取 P。瑞典的 EasyMining 开发了一种酸提取 P (Ash2Phos) 的方法。这项工作调查了在混凝土中使用该工艺 (AW-SSA) 中的酸洗 SSA；作为部分沙子或水泥的替代品。砂浆棱柱的铸件表明，由于 AW-SSA 对水的需求量很大，因此不可能直接替换 10% 的沙子部分。随后，可加工性太低而不能铸造。在用作水泥替代品之前研磨 AW-SSA，另一方面，取得了令人鼓舞的结果。在更换 10% 时，砂浆具有与参考相似的 28 天抗压强度。强度活动指数和 Frattini 测试未显示结论性结果；然而，AW-SSA 可能不是火山灰。然而，地面 AW-SSA 可能具有（潜在的）水力性质，对后期强度发展产生积极影响。替换 10% 的砂浆的 42 天抗压强度超过参考的约 5 MPa。这种潜在的水力特性凸显了将 SSA 转化为两种产品的有趣潜力；磷和混凝土中部分水泥替代的材料。强度活动指数和 Frattini 测试未显示结论性结果；然而，AW-SSA 可能不是火山灰。然而，地面 AW-SSA 可能具有（潜在的）水力性质，对后期强度发展产生积极影响。替换 10% 的砂浆的 42 天抗压强度超过参考的约 5 MPa。这种潜在的水力特性凸显了将 SSA 转化为两种产品的有趣潜力；磷和混凝土中部分水泥替代的材料。强度活动指数和 Frattini 测试未显示结论性结果；然而，AW-SSA 可能不是火山灰。然而，地面 AW-SSA 可能具有（潜在的）水力性质，对后期强度发展产生积极影响。替换 10% 的砂浆的 42 天抗压强度超过参考的约 5 MPa。这种潜在的水力特性凸显了将 SSA 转化为两种产品的有趣潜力；磷和混凝土中部分水泥替代的材料。这种潜在的水力特性凸显了将 SSA 转化为两种产品的有趣潜力；磷和混凝土中部分水泥替代的材料。这种潜在的水力特性凸显了将 SSA 转化为两种产品的有趣潜力；磷和混凝土中部分水泥替代的材料。