MECHANICAL PROPERTIES AND SUSTAINABILITY OF ALUM SLUDGE AS A PARTIAL REPLACEMENT OF FINE AGGREGATE
Main article
Abstract
A substantial volume of alum sludge is generated globally during the water purification process for human consumption. The existing studies have highlighted that the conventional disposal methods pose significant environmental challenges, necessitating the exploration of more sustainable alternatives for alum sludge disposal. This research aims to investigate the workability and compressive strength behavior of traditional concrete by incorporating dry alum sludge as a replacement for fine aggregate (river sand). The alum sludge underwent treatment at 105 °C, was dried, crushed and sieved to achieve a fine particle. This treated alum sludge was then used to replace fine aggregate at varying percentages: 5, 10 and 15%. Specimens were prepared in cube forms (100×100×100mm) targeting a compressive strength of 25 MPa. The study aimed to understand the impact on the filler material properties, workability and strength of both fresh and hardened concrete. The compaction factor test and slump test results were employed to identify the fresh properties of the concrete. The compressive strength tests were conducted at 7, 14 and 28 days. The findings from the compressive strength tests indicated that a replacement of fine aggregate up to 10% was effective in achieving the targeted concrete strength. However, a reduction in workability was observed when the alum sludge filler was increased to 15%, while the 5% filler exhibited superior workability performance. This research contributes to altering certain aspects of concrete behavior by introducing the alum sludge as a replacement material for fine aggregate, thereby promoting environmental sustainability. The findings have sparked considerable debate in the field regarding concrete strength properties and behaviors, emphasizing the importance of exploring alternative materials for more eco-friendly construction practices.
