Upcycling end-of-life bricks in high-performance one-part alkali-activated materials
Upcycling end-of-life bricks in high-performance one-part alkali-activated materials
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DOI：
10.1016/j.dibe.2023.100231
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发表时间：
2023-09
影响因子：
8.2
通讯作者：
Yazeed A. Al-Noaimat;Mehdi Chougan;Mazen J. Al‐Kheetan;M. Yio;Hong S. Wong;S. Ghaffar
中科院分区：
文献类型：
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作者：
Yazeed A. Al-Noaimat;Mehdi Chougan;Mazen J. Al‐Kheetan;M. Yio;Hong S. Wong;S. Ghaffar
单组分碱活性材料（AAMs）通过在其组成中容纳各种废物、工业副产品和报废材料，可以保护自然资源和降低建筑环境的碳含量。本研究探讨了用粉状和骨料两种物理状态的废砖分别部分替代AAMs中的粉煤灰前驱体和天然骨料的可行性。对改性aam的力学性能、微观结构、吸水性、冻融性和耐火性能进行了评价。同时考察了不同比例纳米石墨片的添加效果。结果表明，砖基单组分AAM的力学性能、孔隙结构、吸水率和抗冻融性能与粉煤灰基AAM相当，耐火性能提高65%。将砖作为骨料可使AAMs的抗压强度和抗折强度分别提高17%和27%，并且在暴露于高温后抗压强度没有降低的情况下，抗冻融能力普遍增强。与不含纳米石墨的混合物相比，加入0.1 wt%纳米石墨的混合物进一步提高了30%的抗弯强度，降低了18%的吸水率，并提高了抗冻融性。此外，添加0.5%的纳米石墨提高了复合材料的耐火率，使其强度性能比暴露前提高了19%。
One-part alkali-activated materials (AAMs) can preserve natural resources and lower embodied carbon of the built environment by accommodating various wastes, industrial by-products, and end-of-life materials in their composition. This study investigates the feasibility of using end-of-life bricks in two physical states, powder and aggregate, to partially replace fly ash precursor and natural aggregate in AAMs, respectively. The mechanical characteristics, microstructure, water absorption, freeze-thaw and fire resistance of the modified AAMs were evaluated. The effect of adding different ratios of nano graphite platelets was also investigated. Results showed that brick-based one-part AAMs can achieve mechanical properties, pore structure, water absorption and freeze-thaw resistance comparable to fly ash-based AAM while having 65% better fire resistivity. Incorporating bricks as aggregate resulted in a maximum improvement of 17% and 27% in the AAMs' compressive and flexural strength levels, respectively, and a general enhancement in the freeze-thaw resistance with showing no reduction in compressive strength after exposure to elevated temperature. Incorporating 0.1 wt% nano-graphite further enhanced flexural strength by 30%, decreased water absorption by 18% and improved freeze-thaw resistance compared to the mix without nano-graphite. Moreover, adding up to 0.5% nano-graphite enhanced the fire resistivity of the composite, allowing it to exhibit 19% better strength performance than before exposure.