Thermal parameters.

This study proposes an innovative approach for the recycling of dry wastewater sludge in the production of fired clay bricks, aiming to create environmentally friendly and cost-effective building materials. Consequently, the proposed research focuses on optimizing the thermal and mechanical properties of ceramic bricks, while incorporating sewage sludge as a pore-forming agent in brick manufacturing process. For the assessment of porosity in ceramic brick mixtures with varying volumetric proportions of ash, clay and wastewater sludge, a novel method for microscopy image analysis is proposed. This advanced image segmentation method uses active contours driven by local image information to accurately estimate brick porosity from light microscopy images, coping with light reflections, intensity inhomogeneity, and the defocus effect present on the sample surface. The thermal properties of the ceramic blocks were assessed using non-contact infrared lock-in thermography and thermogravimetric analysis (TGA). The obtained results indicate that incorporating sewage sludge increases porosity, thereby improving the material’s insulating properties, with the cost of reduced mechanical strength. Nevertheless, the compressive strength for a mixture containing 15% of sewage sludge meets the criteria for the production of first-class bricks, according to ASTM C62 standards for brick manufacturing. The present study demonstrates that incorporating sewage sludge into fired clay ceramic bricks production is a feasible and sustainable approach, offering significant advantages for waste management and promoting energy-efficient building design.本研究提出了一种用于烧制黏土砖生产中干燥废水污泥资源化回收的创新方法，旨在制备环境友好且经济高效的建筑材料。据此，本研究聚焦于优化陶瓷砖的热学与力学性能，同时在制砖流程中引入污水污泥作为成孔剂。针对灰分、黏土与废水污泥体积占比各异的陶瓷砖混合料的孔隙率评估需求，本研究提出了一种全新的显微图像分析方法。该先进图像分割技术采用由局部图像信息驱动的主动轮廓（active contours）算法，可从光学显微图像中精准估算砖体孔隙率，能够有效应对样本表面存在的光反射、图像强度不均与散焦效应问题。研究采用非接触式红外锁相热成像技术与热重分析（TGA）对陶瓷砌块的热学性能进行了表征。所得结果表明，掺入污水污泥可提升孔隙率，进而改善材料的隔热性能，但同时会导致力学强度下降。不过，按照美国材料与试验协会（ASTM）制砖标准ASTM C62的要求，掺加15%污水污泥的混合料所制砖体的抗压强度，符合一等砖的生产标准。本研究证实，在烧制黏土陶瓷砖的生产中掺入污水污泥是一种可行且可持续的方案，可为废弃物管理带来显著益处，并助力节能建筑设计的推广。