Nuruzzaman Md, Almeida Jaydon, Amin Md Tanvir Ehsan, Sarker Prabir Kumar
School of Civil and Mechanical Engineering, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
Materials (Basel). 2024 May 14;17(10):2326. doi: 10.3390/ma17102326.
This paper presents a study on the combined use of two by-products, namely quarry dust (QD) and ferronickel slag (FNS), as a full substitute for natural sand to improve the greenness of concrete production. Quarry dust was used in increments of 25% to a maximum of 75% substitution, where nickel slag was used as the remaining proportion of fine aggregate. All the combinations of quarry dust and nickel slag were found to be compliant with AS 2758.1 and they showed notably better grading than 100% sand. In this research, standard concrete tests, such as the slump test for fresh concrete, and compression, tensile and shrinkage tests for hardened concrete, were conducted. Scanning electron microscopy and X-ray diffraction analysis were also conducted for microstructural investigation. The results concluded that the combinations of quarry dust and nickel slag in concrete as a whole substitution of sand provide similar results for these properties. Specifically, 25% quarry dust with 75% nickel slag proved to be the most promising alternative to sand, with compressive and splitting tensile strengths of 62 and 4.29 MPa, respectively, which were 16% and 20% higher than those of the control mix. Also, lower drying shrinkage was observed for this combination compared to the control mix. The higher strength is attributed to the rough texture and angular shape of both quarry dust and nickel slag providing a better mechanical interlocking. The validity of this result has also been confirmed through image analysis of micrographs from various specimens. In microstructural investigations, specimens with QD and FNS exhibited fewer voids and a more compact surface compared to the control specimen. This shows the potential for further research into the use of quarry dust and nickel slag in the production of green concrete.
本文介绍了一项关于联合使用两种副产品（即采石场粉尘（QD）和镍铁渣（FNS））作为天然砂的完全替代品以提高混凝土生产绿色度的研究。采石场粉尘以25%的增量使用，最高替代量为75%，其中镍渣用作细骨料的剩余比例。发现采石场粉尘和镍渣的所有组合均符合AS 2758.1标准，并且它们的级配明显优于100%的砂。在本研究中，进行了标准混凝土试验，如新拌混凝土的坍落度试验以及硬化混凝土的抗压、抗拉和收缩试验。还进行了扫描电子显微镜和X射线衍射分析以进行微观结构研究。结果表明，混凝土中采石场粉尘和镍渣作为砂的整体替代品在这些性能方面提供了相似的结果。具体而言，25%的采石场粉尘与75%的镍渣被证明是最有前途的砂替代品，其抗压强度和劈裂抗拉强度分别为62 MPa和4.29 MPa，比对照混合料分别高出16%和20%。此外，与对照混合料相比，该组合的干燥收缩率更低。更高的强度归因于采石场粉尘和镍渣的粗糙质地和棱角形状提供了更好的机械联锁。通过对各种试件微观照片的图像分析也证实了该结果的有效性。在微观结构研究中，与对照试件相比，含有QD和FNS的试件孔隙较少且表面更致密。这表明在绿色混凝土生产中使用采石场粉尘和镍渣还有进一步研究的潜力。
