Sujatha Aanattuthadathil, Balakrishnan Santhamma Deepa
Division of Civil Engineering, School of Engineering, Cochin University of Science and Technology, Kochi, 682 022, Kerala State, India.
Environ Sci Pollut Res Int. 2025 Jun;32(27):16340-16360. doi: 10.1007/s11356-025-36655-2. Epub 2025 Jun 26.
The rising demand for concrete is rapidly depleting finite resources of its constituent materials, such as sand and gravel. Addressing this issue demands alternative recycled or bio-based eco-friendly sources for aggregates. In recent decades, crushed coconut shells have been utilized as an alternative for coarse aggregate to produce concrete. However, the key challenges in producing structural-grade coconut shell aggregate concrete (CSAC) include high cement consumption and high absorption of the coconut shell aggregate (CSA). Therefore, in this study, cement was partially replaced with GGBFS (10% and 20%) to reduce cement consumption, and treated CSA was used (using grout coating) to improve the quality of CSA in CSAC. The study aimed to evaluate the strength and durability properties of CSAC with GGBFS and treated CSA. The properties of CSAC mixes such as compressive strength, water absorption, sorptivity, rapid chloride penetration, and resistance to chemical attacks were evaluated. The experimental studies show that the water absorption value of treated CSA concrete with 10% GGBFS mix(T/10) was 10.69% less compared to untreated CSA concrete with 10% GGBFS mix(U/10) at 180 days, respectively. Similarly, the sorptivity of the T/10 mix was 11.86% less compared to U/10. The 180-day compressive strength of the T/10 mix was 7.51% and 2.32% more compared to the control CSAC mix(U/0) and U/10 mix, respectively. The environmental impacts of CSAC were evaluated by fast-track LCA and compared with conventional aggregate concrete (CC). The carbon footprint values of the T/10 mix and CC mix were 462.51 kg COe/ m and 483.82 kg COe/ m, respectively. This study proves that the strength, durability, and ecological properties of CSAC were improved by incorporating GGBFS and treated CSA into the concrete mix.
对混凝土不断增长的需求正在迅速耗尽其组成材料（如沙子和砾石）的有限资源。解决这一问题需要替代的回收或生物基环保骨料来源。近几十年来，碎椰子壳已被用作粗骨料的替代品来生产混凝土。然而，生产结构级椰子壳骨料混凝土（CSAC）的关键挑战包括水泥消耗量高和椰子壳骨料（CSA）吸水率高。因此，在本研究中，用粒化高炉矿渣（GGBFS）部分替代水泥（10%和20%）以减少水泥消耗，并使用处理过的CSA（采用灌浆涂层）来提高CSAC中CSA的质量。该研究旨在评估掺加GGBFS和处理过的CSA的CSAC的强度和耐久性性能。对CSAC混合料的性能进行了评估，如抗压强度、吸水率、吸渗系数、快速氯离子渗透和耐化学侵蚀性。试验研究表明，180天时，掺10% GGBFS的处理过的CSA混凝土（T/10）的吸水率比未处理的掺10% GGBFS的CSA混凝土（U/10）低10.69%。同样，T/10混合料的吸渗系数比U/10低11.86%。T/10混合料180天的抗压强度分别比对照CSAC混合料（U/0）和U/10混合料高7.51%和2.32%。通过快速生命周期评估（LCA）对CSAC的环境影响进行了评估，并与传统骨料混凝土（CC）进行了比较。T/10混合料和CC混合料的碳足迹值分别为462.51 kg COe/m和483.82 kg COe/m。本研究证明，通过在混凝土混合料中掺入GGBFS和处理过的CSA，CSAC的强度、耐久性和生态性能得到了改善。
