This study investigates the mechanical and thermal properties of cement mortars incorporating two types of waste slags: ferrochrome (FeCr) slag aggregate was used as a replacement for sand at ratios of 25, 50, 75 and 100 wt%, and ground granulated blast furnace slag (GGBS) was used as a partial replacement for cement at a ratio of 25 wt%. Compressive strength, volume of permeable voids (VPV), drying shrinkage, and thermal conductivity tests were conducted after 28 days of curing. The microstructure characteristics were examined by scanning electron microscopy. The experimental results revealed that FeCr waste aggregates could satisfactorily replace natural fine sand in cement mortars up to 25 wt% without a remarkable degradation of compressive strength. Furthermore, increasing the replacement ratios of FeCr aggregates by over 25 wt% resulted in a noticeable decrease in thermal conductivity and an increase in the permeable void content of cement mortars. The increased VPV of FeCr slag-blended mortars led to a significant increase in drying shrinkage. The integration of GGBS with FeCr aggregates led to enhanced compressive strength and reduced VPV and drying shrinkage, thus contributing to an improved microstructure.

中文翻译：

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掺入混合废渣的水泥砂浆的热物理、机械和微观结构特性研究

本研究调查了掺入两种废渣的水泥砂浆的机械和热性能：铬铁 (FeCr) 矿渣骨料被用作以 25、50、75 和 100 重量％的比例代替砂，以及磨碎的粒状高炉矿渣(GGBS) 以 25 wt% 的比例用作水泥的部分替代品。在固化 28 天后进行抗压强度、渗透空隙体积 (VPV)、干燥收缩率和热导率测试。通过扫描电子显微镜检查微观结构特征。实验结果表明，FeCr 废骨料可以令人满意地替代水泥砂浆中高达 25 wt% 的天然细砂，而不会显着降低抗压强度。此外，将 FeCr 骨料的替代率提高 25% 以上会导致导热系数显着降低，水泥砂浆的渗透空隙率增加。FeCr 矿渣混合砂浆的 VPV 增加导致干燥收缩率显着增加。GGBS 与 FeCr 骨料的结合提高了抗压强度并降低了 VPV 和干燥收缩，从而有助于改善微观结构。