Basnett Anmol, Sekar Anandh, Nachiar Sindhu, Alaneme George Uwadiegwu
Department of Civil Engineering, SRM Institute of Science and Technology, Kattankulathur, Chennai, India.
Department of Civil, School of Engineering and Applied Sciences, Kampala International University, Kampala, Uganda.
Sci Rep. 2025 Jul 1;15(1):21424. doi: 10.1038/s41598-025-07551-z.
The growing need for sustainable construction materials has driven significant efforts to reduce dependence on virgin raw materials and minimize construction and demolition (C&D) waste. In this context, recycled aggregates and alternative fillers have emerged as promising substitutes to conventional materials, contributing to environmental sustainability while enhancing concrete performance. This study investigates the influence of bond strength in three distinct concrete mixes: Mixed Recycled Aggregate (MRA) concrete, Treated Mixed Recycled Aggregate (TMRA) concrete, and TMRA incorporating Olivine Sand (TMRAOS) concrete. Experimental analyses, including compressive strength, pull-out tests and microstructural evaluations using HRSEM, revealed that the incorporation of treated MRA and Olivine Sand significantly enhanced the bond strength at the rebar-concrete interface. The TMRAOS mix exhibited superior mechanical strength, showing improvements of 28.55% and 11.90% compared to MRA and TMRA mixes, respectively. In terms of bond performance, bond strength increased from 4.48 to 5.85 MPa in MRA to 6.11-8.05 MPa in TMRA, and further to 6.35-8.67 MPa in TMRAOS, with corresponding slip values of 2.48-4.36, 2.75-4.87, and 2.96-5.23 mm, respectively. It also demonstrated improved stress distribution, reduced crack propagation, and enhanced bond-slip behaviour. Finite element modelling (FEM) further validated these findings, showing strong agreement between experimental and numerical results. This study highlights TMRAOS concrete as an eco-friendly and structurally efficient alternative to conventional concrete, with strong potential for sustainable infrastructure applications.
对可持续建筑材料日益增长的需求促使人们做出巨大努力，以减少对原生原材料的依赖，并将建筑和拆除（C&D）废物降至最低。在这种背景下，再生骨料和替代填料已成为传统材料的有前景的替代品，在提高混凝土性能的同时促进了环境可持续性。本研究调查了三种不同混凝土混合料的粘结强度影响：混合再生骨料（MRA）混凝土、处理后的混合再生骨料（TMRA）混凝土以及掺入橄榄石砂的TMRA（TMRAOS）混凝土。实验分析，包括抗压强度、拉拔试验以及使用高分辨率扫描电子显微镜（HRSEM）的微观结构评估，结果表明，掺入处理后的MRA和橄榄石砂显著提高了钢筋与混凝土界面的粘结强度。TMRAOS混合料表现出优异的机械强度，与MRA和TMRA混合料相比，分别提高了28.55%和11.90%。在粘结性能方面，MRA的粘结强度从4.48MPa提高到TMRA的6.11 - 8.05MPa，进而提高到TMRAOS的6.35 - 8.67MPa，相应的滑移值分别为2.48 - 4.36mm、2.75 - 4.87mm和2.96 - 5.23mm。它还表现出改善的应力分布、减少的裂纹扩展以及增强的粘结-滑移行为。有限元建模（FEM）进一步验证了这些结果，实验结果与数值结果显示出高度一致性。本研究强调TMRAOS混凝土是一种生态友好且结构高效的传统混凝土替代品，在可持续基础设施应用方面具有巨大潜力。
