Lee Jeong-Bae
Department of Smart Construction and Environmental Engineering, Daejin University, 1007 Hoguk-ro, Pocheon-si 11159, Republic of Korea.
Materials (Basel). 2024 Nov 18;17(22):5625. doi: 10.3390/ma17225625.
The global construction industry faces increasing pressure to adopt sustainable practices, particularly in reducing cement-related CO emissions. This study investigates the feasibility of using treated wastewater sludge (WWS) as a partial replacement for cement in repair mortars. Treated (A-WWS) and untreated (B-WWS) sludge were evaluated for their effects on workability, mechanical strength, durability, and environmental impact. Flow tests revealed that A-WWS maintained workability similar to the control mixture, while B-WWS reduced flow due to its coarser particles. Compressive strength tests showed that a 10% A-WWS substitution improved strength due to enhanced pozzolanic reactions, while untreated sludge reduced overall strength. Water absorption and bond strength tests confirmed the improved durability of A-WWS mortars. Chemical attack resistance testing demonstrated that A-WWS significantly reduced carbonation depth and chloride penetration, enhancing durability. Microstructural analysis supported these findings, showing denser hydration products in pretreated sludge mixtures. An environmental hazard analysis confirmed low heavy metal content, making sludge-based mortars environmentally safe. Although wastewater sludge shows promise as a partial cement replacement, the processing energy demand remains substantial, necessitating further investigation into energy-efficient treatment methods. This research highlights the potential of pretreated WWS as a sustainable alternative in construction, contributing to reduced cement consumption and environmental impact without compromising material performance. The findings support the viability of sludge-based repair mortars for practical applications in the construction industry.
全球建筑业面临着越来越大的压力，需要采用可持续发展的做法，特别是在减少与水泥相关的碳排放方面。本研究调查了使用经处理的废水污泥（WWS）作为修补砂浆中水泥的部分替代品的可行性。对经处理的（A-WWS）和未经处理的（B-WWS）污泥在工作性、机械强度、耐久性和环境影响方面的效果进行了评估。流动试验表明，A-WWS保持了与对照混合物相似的工作性，而B-WWS由于其颗粒较粗而降低了流动性。抗压强度试验表明，10%的A-WWS替代物由于火山灰反应增强而提高了强度，而未经处理的污泥则降低了整体强度。吸水率和粘结强度试验证实了A-WWS砂浆的耐久性有所提高。抗化学侵蚀试验表明，A-WWS显著降低了碳化深度和氯离子渗透，提高了耐久性。微观结构分析支持了这些发现，显示预处理污泥混合物中的水化产物更致密。环境危害分析证实了重金属含量低，使基于污泥的砂浆在环境上是安全的。尽管废水污泥作为水泥的部分替代品显示出前景，但处理所需的能源需求仍然很大，需要进一步研究节能处理方法。这项研究突出了预处理WWS作为建筑领域可持续替代品的潜力，有助于在不影响材料性能的情况下减少水泥消耗和环境影响。研究结果支持了基于污泥的修补砂浆在建筑业实际应用中的可行性。
