Department of Civil Engineering, Mehran University of Engineering and Technology, Shaheed Zulfiqar Ali Bhutto Campus, Khairpur Mirs', Sindh, Pakistan.
Jamilus Research Centre, Faculty of Civil Engineering and Built Environment, Universiti Tun Hussein Onn Malaysia, Parit Raja, 86400, Batu Pahat, Johor, Malaysia.
Environ Sci Pollut Res Int. 2021 Aug;28(29):38947-38968. doi: 10.1007/s11356-021-13435-2. Epub 2021 Mar 20.
The production of cement contributes to 10% of global carbon dioxide (CO) pollution and 74 to 81% towards the total CO pollution by concrete. In addition to that, its low strength-to-weight ratio, high density and thermal conductivity are among the few limitations of heavy weight concrete. Therefore, this study was carried out to provide a solution to these limitations by developing innovative eco-friendly lightweight foamed concrete (LFC) of 1800 kg/m density incorporating 20-25% palm oil fuel ash (POFA) and 5-15% eggshell powder (ESP) by weight of total binder as supplementary cementitious material (SCM). The influence of combined utilization of POFA and ESP on the fresh state properties of eco-friendly LFC was determined using the J-ring test. To determine the mechanical properties, a total of 48 cubes and 24 cylinders were prepared for compressive strength, splitting tensile strength and modulus of elasticity each. A total of 24 panels were prepared to determine the thermal properties in terms of surface temperature and thermal conductivity. Furthermore, to assess the environmental impact and eco-friendliness of the developed LFC, the embodied carbon and eco-strength efficiency was calculated. It was determined that the utilization of POFA and ESP reduced the workability slightly but enhanced the mechanical properties of LFC (17.05 to 22.60 MPa compressive strength and 1.43 to 2.61 MPa tensile strength), thus satisfies the ACI213R requirements for structural lightweight concrete and that it can be used for structural applications. Additionally, the thermal conductivity reduced ranging from 0.55 to 0.63 W/mK compared to 0.82 W/mK achieved by control sample. Furthermore, the developed LFC showed a 16.96 to 33.55% reduction in embodied carbon and exhibited higher eco-strength efficiency between 47.82 and 76.97%. Overall, the combined utilization of POFA and ESP as SCMs not only enhanced the thermo-mechanical performance, makes the sustainable LFC as structural lightweight concrete, but also has reduced the environmental impacts caused by the disposal of POFA and ESP in landfills as well as reducing the total CO emissions during the production of eco-friendly LFC.
水泥生产导致全球二氧化碳（CO）污染的 10%，而混凝土导致的 CO 污染总量的 74%至 81%。此外，其低的比强度、高密度和热导率是重质混凝土的几个局限性之一。因此，本研究通过开发创新的环保轻骨料泡沫混凝土（LFC）来解决这些局限性，该混凝土密度为 1800kg/m，总胶凝材料重量的 20-25%为棕榈油燃料灰（POFA），5-15%为蛋壳粉（ESP）作为辅助胶凝材料（SCM）。通过 J 环试验确定了 POFA 和 ESP 的联合利用对环保 LFC 新拌性能的影响。为了确定力学性能，共制备了 48 个立方体和 24 个圆柱体，每个分别进行抗压强度、劈裂抗拉强度和弹性模量试验。共制备了 24 个面板来确定表面温度和热导率方面的热性能。此外，为了评估所开发的 LFC 的环境影响和环保性，计算了包含的碳和生态强度效率。结果表明，POFA 和 ESP 的利用略微降低了工作性，但提高了 LFC 的力学性能（抗压强度从 17.05MPa 提高到 22.60MPa，劈裂抗拉强度从 1.43MPa 提高到 2.61MPa），从而满足 ACI213R 对结构轻骨料混凝土的要求，可用于结构应用。此外，与控制样品达到的 0.82W/mK 相比，热导率降低了 0.55-0.63W/mK。此外，所开发的 LFC 的包含的碳减少了 16.96-33.55%，生态强度效率在 47.82-76.97%之间提高。总的来说，POFA 和 ESP 作为 SCM 的联合利用不仅提高了热机械性能，使可持续的 LFC 成为结构轻骨料混凝土，而且减少了 POFA 和 ESP 在垃圾填埋场处置造成的环境影响，以及减少了环保 LFC 生产过程中的总 CO 排放量。
