Endale Solomon Asrat, Yehualaw Mitiku Damtie, Taffese Woubishet Zewdu, Vo Duy-Hai
Faculty of Civil and Water Resource Engineering, Bahir Dar Institute of Technology, Bahir Dar University, Bahir Dar P.O. Box 26, Ethiopia.
Department of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO 65401, USA.
Materials (Basel). 2025 May 1;18(9):2080. doi: 10.3390/ma18092080.
This research aims to address the environmental and economic challenges associated with conventional concrete by partially replacing cement-the most polluting, expensive, and energy-intensive ingredient-with industrial paint sludge ash (PSA), a highly contaminated industrial waste that is typically landfilled. Mortar mixtures were prepared with PSA replacement levels ranging from 0% to 20% in 5% increments while maintaining a constant water-to-binder ratio of 0.48. This study comprehensively evaluated the fresh, mechanical, durability, and microstructural properties of the PSA-modified mortar to assess its potential as an ecofriendly construction material. Results showed that as PSA content increased, the fresh properties, such as workability/slump flow and setting time, decreased, while the water demand for attaining normal consistency increased. Soundness tests indicated expansion up to 15% PSA replacement, beyond which expansion became more pronounced. Compressive strength improved significantly with PSA replacements of 5% to 15% compared to the control sample, with a slight decline at 15% relative to 5% and 10%. This trend was consistent with bulk density and ultrasonic pulse velocity measurements. Furthermore, the incorporation of PSA enhanced key durability properties, including water absorption, sulfate resistance, and porosity reduction, up to 15% PSA replacement. Microstructural analysis using SEM, XRD, TGA/DTA, and FTIR confirmed that PSA inclusion led to increased mortar densification, with the 10% PSA mix exhibiting thermal stability and minimal mass loss at elevated temperatures. FTIR spectra further indicated improved composition with higher PSA content. Overall, PSA proved to be a viable partial cement replacement, offering enhanced mortar properties without compromising performance. Its use contributes to sustainability by reducing reliance on cement, lowering construction costs, and eliminating the environmental and logistical burdens of paint sludge disposal.
本研究旨在通过用工业漆渣灰（PSA）部分替代水泥（最具污染性、昂贵且能源密集型的成分）来应对与传统混凝土相关的环境和经济挑战，工业漆渣灰是一种通常被填埋的高污染工业废料。制备了PSA替代水平从0%到20%（以5%的增量）的砂浆混合物，同时保持水胶比恒定为0.48。本研究全面评估了PSA改性砂浆的新拌性能、力学性能、耐久性和微观结构性能，以评估其作为生态友好型建筑材料的潜力。结果表明，随着PSA含量的增加，新拌性能，如工作性/坍落度流动度和凝结时间降低，而达到标准稠度所需的用水量增加。安定性试验表明，在PSA替代量高达15%时会有膨胀，超过该替代量后膨胀变得更加明显。与对照样品相比，当PSA替代量为5%至15%时，抗压强度显著提高，在15%时相对于5%和10%略有下降。这一趋势与堆积密度和超声脉冲速度测量结果一致。此外，在PSA替代量高达15%时，掺入PSA增强了关键的耐久性性能，包括吸水率、抗硫酸盐性和孔隙率降低。使用扫描电子显微镜（SEM）、X射线衍射（XRD）、热重/差示热分析（TGA/DTA）和傅里叶变换红外光谱（FTIR）进行的微观结构分析证实，掺入PSA导致砂浆致密化增加，含10% PSA的混合物在高温下表现出热稳定性和最小质量损失。FTIR光谱进一步表明，随着PSA含量的增加，成分有所改善。总体而言，PSA被证明是一种可行的部分水泥替代品，在不影响性能的情况下提高了砂浆性能。其使用通过减少对水泥的依赖、降低建筑成本以及消除漆渣处置的环境和物流负担，有助于实现可持续发展。
