Faculty of Civil Engineering and Architecture, Kaunas University of Technology, Kaunas, LT 44249, Lithuania.
Department of Civil Engineering, Maharaja Agrasen Institute of Technology, Maharaja Agrasen University, Baddi 174103, India.
Sci Total Environ. 2022 Sep 10;838(Pt 3):156407. doi: 10.1016/j.scitotenv.2022.156407. Epub 2022 Jun 2.
In order to mitigate the problems associated with the deposition of biomass ashes, it becomes essential to use these materials efficiently. One solution to the problem is utilization of these wastes in the concrete industry. Due to the massive development of infrastructure, the demand for cement is tremendously rising which results in the surge of cement concrete by 30 billion tonnes every year. Plant-based straw and husk ashes are residual waste containing high amounts of silica, which can also be accommodated as a pozzolanic material in concrete. This study presents a complete review of various husk and straw ashes and their impacts on the fresh and hardened properties of concrete including its preparation, microstructure, workability, compressive strength, splitting tensile strength and flexural strength. Special emphasis has been given to the durability characteristics of concrete focussing on porosity, water penetration, carbonation, acid resistance, sulphate, and chloride attack. The data gathered shows that fineness of ashes provides filler and pore refinement effect and gains additional hydration products, resulting in an improvement of the mechanical and durability properties of concrete. The addition of ashes as supplementary cementitious materials in concrete enhances the mechanical performance up to a certain replacement. The optimum level of replacement for rice husk ash, wheat straw ash, and sugarcane straw ash was observed at 10-20%. While wheat husk ash, groundnut husk ash, rice straw ash, and millet husk ash provide optimum strength gains at 10% replacement of OPC. An increase in the replacement content of mostly ashes has a positive effect on water absorption and resistance to acid, sulphate, and chloride attacks.
为了减轻生物质灰分沉积所带来的问题，有效地利用这些材料变得至关重要。解决该问题的一种方法是在混凝土行业中利用这些废物。由于基础设施的大规模发展，对水泥的需求急剧增加，导致每年水泥混凝土的产量增加 300 亿吨。基于植物的秸秆和壳灰是含有大量二氧化硅的残余废物，也可以作为火山灰材料容纳在混凝土中。本研究全面回顾了各种壳灰和秸秆灰及其对混凝土的新拌和硬化性能的影响，包括其制备、微观结构、工作性、抗压强度、劈裂抗拉强度和弯曲强度。特别强调了混凝土的耐久性特性，重点关注孔隙率、水渗透、碳化、耐酸、硫酸盐和氯化物侵蚀。收集的数据表明，灰分的细度提供了填充和细化孔隙的效果，并获得了额外的水化产物，从而提高了混凝土的力学和耐久性性能。在混凝土中添加灰分作为辅助胶凝材料，可以在一定程度上提高其力学性能。稻壳灰、麦秸灰和甘蔗秸灰的最佳替代率为 10-20%。而麦壳灰、花生壳灰、稻秸灰和小米壳灰在替代 10%的波特兰水泥时，可获得最佳的强度增长。大多数灰分的替代含量增加对吸水性和耐酸、硫酸盐和氯化物侵蚀有积极影响。
