The utilization of recycled aggregate (RA) from the construction and demolition waste (C&DW) in civil engineering applications, has proven to be an eco-efficient environmentally friendly approach to overcome the current environmental concerns. Nevertheless, the poor quality of RA has limited its utilization in high-grade civil engineering applications. To maximize and promote the use of RA, it is essential that an appropriate process of treatment methods is included in the production of RA to improve its properties. This research aimed to examine the effects of various enhancement methods on the mechanical properties (consistency, compressive strength, flexural strength, tensile splitting strength, and elastic modulus) of recycled aggregate concrete (RAC). This research also included microstructure investigation using Scan Electron Microscopy (SEM) images. The enhancement methods used were treating RA by Soaking in Cement-Pulverized Fuel Ash-Silica Fume solution (SCP), Sand Envelope Mixing Approach (SE), and their combination (SCP + SE). The enhanced RACs showed an increased 28-day compressive strength of up to 46 MPa suitable for structural applications. The tensile splitting strength, flexural strength, and modulus elasticity values of the enhanced RACs were 10%, 16%, and 6% higher than that of the untreated RAC. The improved mechanical performance of the enhanced RAC was attributed to the strengthened interfacial transition zone, better overall interlocking of the treated RA with the new cement paste, filled-up pores and micro-cracks, reduced water absorption, and improved aggregate impact value. The SEM images for the enhanced RACs showed better-compacted microstructure, lesser pores and microcracks. The application of the proposed innovative regime of enhancement methods is anticipated to promote the use of RA in the construction industry and provide a better scientific understanding of the performance of concrete produced with 100% treated RA from the C&DW for structural applications.

在土木工程应用中利用建筑和拆除废物 (C&DW) 中的再生骨料 (RA) 已被证明是一种解决当前环境问题的生态高效环保方法。然而，RA 的低质量限制了其在高级土木工程应用中的应用。为了最大限度地利用和促进 RA 的使用，必须在 RA 的生产中包括适当的处理方法过程以改善其性能。本研究旨在检验各种增强方法对再生骨料混凝土 (RAC) 的力学性能（稠度、抗压强度、抗弯强度、拉伸劈裂强度和弹性模量）的影响。这项研究还包括使用扫描电子显微镜 (SEM) 图像进行的微观结构研究。使用的增强方法是通过浸泡在水泥-粉煤灰-硅灰溶液 (SCP)、砂包络混合方法 (SE) 以及它们的组合 (SCP + SE) 来治疗 RA。增强型 RAC 的 28 天抗压强度提高了 46 MPa，适用于结构应用。增强型 RAC 的拉伸劈裂强度、弯曲强度和模量弹性值比未处理的 RAC 高 10%、16% 和 6%。增强型 RAC 力学性能的改善归因于界面过渡区的强化、处理后的 RA 与新水泥浆体的整体互锁性更好、孔隙和微裂缝的填充、吸水率的降低以及骨料冲击值的提高。增强型 RAC 的 SEM 图像显示出更好的压实微观结构、更少的孔隙和微裂纹。所提议的增强方法创新制度的应用预计将促进 RA 在建筑行业的使用，并为使用来自 C&DW 的 100% 处理的 RA 生产的混凝土用于结构应用的性能提供更好的科学理解。