Given the rising popularity of foam concrete (FC) for both structural and insulating purposes, evaluating the feasibility of recycling after its lifespan is crucial in the context of the growing emphasis on sustainable building practices. One approach to recycling FC incorporating microencapsulated phase change material (MPCM) involves utilizing recycled foam concrete powder (RFCP) as an additive in cement composites. This article aims to investigate the impact of RFCP without and with MPCM when employed as a partial replacement for cement in mortars. Furthermore, the study verifies various processing methods such as crushing, grinding, and heat treatment for RFCP. The results reveal that introducing RFCP, regardless of the MPCM presence and processing method, significantly affects the properties of both cement and mortar. The presence of MPCM in RFCP negatively influences the flowability of fresh mortars, delays the setting time, and reduces the hydration heat within the first 48 h. However, the presence of MPCM does not significantly affect mortars' strength and water absorption but simultaneously it increases shrinkage and decreases thermal conductivity. Grinding RFCP mitigates the adverse effects of MPCM, while thermal processing removes MPCM from RFCP, albeit with an associated increase in water demand. A noteworthy finding is that mortars having 20 % RFCP, with or without MPCM, exhibit compressive strengths exceeding 16 MPa and 42.5 MPa after 2 and 28 days, respectively. These results meet the requirements outlined in EN-196-1 for cement of class 42.5, highlighting the potential to produce CEM II/A-F 42.5 using RFCP with MPCM.

中文翻译：

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利用废弃泡沫混凝土与 MPCM 作为砂浆中水泥的替代材料

鉴于泡沫混凝土（FC）在结构和隔热方面的日益普及，在人们日益重视可持续建筑实践的背景下，评估其使用寿命后回收的可行性至关重要。回收利用微胶囊相变材料 (MPCM) 的 FC 的一种方法是利用回收泡沫混凝土粉末 (RFCP) 作为水泥复合材料的添加剂。本文旨在研究 RFCP 在用作砂浆中水泥的部分替代品时，不含和含有 MPCM 的影响。此外，该研究还验证了RFCP的破碎、研磨和热处理等各种加工方法。结果表明，无论 MPCM 的存在和加工方法如何，引入 RFCP 都会显着影响水泥和砂浆的性能。 RFCP 中 MPCM 的存在会对新拌砂浆的流动性产生负面影响，延迟凝固时间，并降低前 48 小时内的水化热。然而，MPCM 的存在不会显着影响砂浆的强度和吸水率，但同时会增加收缩率并降低导热率。研磨 RFCP 可以减轻 MPCM 的不利影响，而热处理则可以从 RFCP 中去除 MPCM，尽管这会导致需水量的增加。一个值得注意的发现是，含有 20% RFCP 的砂浆，无论是否含有 MPCM，在 2 天和 28 天后的抗压强度分别超过 16 MPa 和 42.5 MPa。这些结果满足 EN-196-1 中对 42.5 级水泥的要求，凸显了使用 RFCP 和 MPCM 生产 CEM II/AF 42.5 的潜力。