Abbass Wasim, Abbas Safeer, Aslam Fahid, Ahmed Ali, Ahmed Tauqir, Hashir Agha, Mamdouh Amr
Department of Civil Engineering, University of Engineering and Technology, Lahore 54890, Pakistan.
Department of Civil Engineering, College of Engineering in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj 16273, Saudi Arabia.
Materials (Basel). 2022 Jun 4;15(11):4003. doi: 10.3390/ma15114003.
Burnt clay bricks are one of the most important building units worldwide, are easy and cheap to make, and are readily available. However, the utilization of fertile clay in the production of burnt clay bricks is also one of the causes of environmental pollution because of the emission of greenhouse gases from industrial kilns during the large-scale burning process. Therefore, there is a need to develop a new class of building units (bricks) incorporating recycled industrial waste, leading toward sustainable construction by a reduction in the environmental overburden. This research aimed to explore the potential of untreated coal ash for the manufacturing of building units (coal ash unburnt bricks). Coal ash unburnt bricks were manufactured at an industrial brick plant by applying a pre-form pressure of 3 MPa and later curing them via water sprinkling in a control shed. Various proportions of coal ash (i.e., 30, 35, 40, 45, 50, and 55%) were employed to investigate the mechanical and durability-related properties of the resulting bricks, then they were compared with conventional burnt clay bricks. Compressive strength, flexural strength, an initial rate of water absorption, efflorescence, microstructural analysis via scanning electron microscopy, and cost analysis were conducted. The results of the compressive strength tests revealed that the compressive strength of coal ash unburnt brick decreased with an increase in the content of coal ash; however, up to a 45% proportion of coal ash, the minimum required compressive strength specified by ASTM C62 and local building codes was satisfied. Furthermore, bricks incorporating up to 45% of coal ash also satisfied the ASTM C62 requirements for water absorption. Coal ash unburnt bricks are lighter in weight owing to their porous developed microstructure. The cost analysis showed that the utilization of untreated, locally available coal ash in brick production leads us on the path toward more economical and sustainable building units.
烧粘土砖是全球最重要的建筑材料之一，制作简单且成本低廉，原料也很容易获取。然而，在烧粘土砖生产过程中使用肥沃的粘土也是环境污染的原因之一，因为在大规模烧制过程中工业窑炉会排放温室气体。因此，有必要开发一类新型建筑材料（砖），将回收的工业废料纳入其中，通过减轻环境负担来实现可持续建设。本研究旨在探索未经处理的煤灰用于制造建筑材料（煤灰免烧砖）的潜力。煤灰免烧砖在一家工业砖厂制造，施加3兆帕的预成型压力，随后在控制棚中通过洒水进行养护。采用不同比例的煤灰（即30%、35%、40%、45%、50%和55%）来研究所得砖块的力学性能和耐久性相关性能，然后将其与传统烧粘土砖进行比较。进行了抗压强度、抗弯强度、初始吸水率、泛霜、通过扫描电子显微镜进行的微观结构分析以及成本分析。抗压强度测试结果表明，煤灰免烧砖的抗压强度随着煤灰含量的增加而降低；然而，煤灰比例高达45%时，满足了美国材料与试验协会C62标准和当地建筑规范规定的最低抗压强度要求。此外，煤灰含量高达45%的砖块也满足了美国材料与试验协会C62标准对吸水率的要求。由于其多孔的微观结构，煤灰免烧砖重量更轻。成本分析表明，在砖生产中使用未经处理的当地可用煤灰使我们朝着更经济、可持续的建筑材料迈进。
