Kanagaraj Balamurali, Shaji Shinu, Jafrin Meshach, Raj R Samuvel, Anand N, Lubloy Eva
Department of Civil Engineering, Karunya Institute of Technology and Sciences, Coimbatore, India.
Department of Construction Materials and Technologies, Faculty of Civil Engineering, Budapest University of Technology and Economics, Budapest, 1521, Hungary.
Heliyon. 2024 Oct 22;10(21):e39676. doi: 10.1016/j.heliyon.2024.e39676. eCollection 2024 Nov 15.
The increasing scarcity of natural materials and rising construction costs have prompted the need for alternative materials that can match the performance of conventional aggregates. This study explores the use of recycled aggregate concrete (RAC) as a sustainable alternative, supplemented with natural and synthetic fibers to overcome the inherent strength limitations caused by the residual cement paste on the aggregate surface. To enhance the mechanical and thermal stability of RAC, steel, polypropylene, and coconut fibers were incorporated. The rheological, hardened, and post-fire properties of fiber-reinforced RAC were thoroughly investigated. After 28 days, the porosity of RAC with fiber reinforcement was observed to be less than 2 %. The concrete was also exposed to elevated temperatures as per ISO 834 guidelines to assess its thermal performance. Key parameters such as mass loss, crack width, porosity, and strength degradation were analyzed. Image analysis was used to track surface modifications and measure surface porosity after heating. Among the fiber types, steel fiber reinforced concrete exhibited superior mechanical and thermal performance, followed by coconut fiber reinforced concrete, making coconut fibers a viable natural alternative to synthetic fibers. RAC without fibers displayed the highest porosity (20 % and 32 %) after exposure to 821 °C and 1029 °C, respectively. Strength degradation ranged from 40 to 50 % after heating to 821 °C, increasing to 74-80 % at 1029 °C, irrespective of fiber type. This research highlights the potential of fiber-reinforced RAC for structural applications, offering a sustainable solution with comparable strength and durability to conventional concrete.
天然材料日益稀缺以及建筑成本不断上升，促使人们需要能与传统骨料性能相媲美的替代材料。本研究探索了使用再生骨料混凝土（RAC）作为一种可持续的替代材料，并辅以天然纤维和合成纤维，以克服骨料表面残留水泥浆所导致的固有强度限制。为提高RAC的力学和热稳定性，掺入了钢纤维、聚丙烯纤维和椰纤维。对纤维增强RAC的流变性能、硬化性能和火灾后性能进行了深入研究。28天后，观察到纤维增强RAC的孔隙率小于2%。还按照ISO 834指南将混凝土暴露于高温下，以评估其热性能。分析了质量损失、裂缝宽度、孔隙率和强度退化等关键参数。使用图像分析来跟踪加热后的表面变化并测量表面孔隙率。在各种纤维类型中，钢纤维增强混凝土表现出卓越的力学和热性能，其次是椰纤维增强混凝土，这使得椰纤维成为合成纤维可行的天然替代品。无纤维的RAC在分别暴露于821°C和1029°C后，孔隙率最高（分别为20%和32%）。加热至821°C后强度退化范围为40%至50%，在1029°C时增至74 - 80%，与纤维类型无关。本研究突出了纤维增强RAC在结构应用中的潜力，提供了一种强度和耐久性与传统混凝土相当的可持续解决方案。
